BUILDING MATERIALS AND STRUCTURES REPORTS

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BMSl Research on Building Materials and Structures for Use in Low-Cost Housing 10^ BMS2 Methods of Determining the Structural Properties of Low-Cost House Constructions 10^ BMS3 Suitability of Fiber Insulating Lath as a Plaster Base 10^ BMS4 Accelerated Aging of Fiber Building Boards 10^ BMS5 Structural Properties of Six Masonry Wall Constructions 15^ BMS6 Survey of Roofing Materials in the Southeastern States 15^ BMS7 Water Permeability of Masonry Walls 10^ BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel 10^ BMS9 Structural Properties of the Insulated Steel Construction Company's "Frameless-Steel" Constructions for Walls, Partitions, Floors, and Roofs 100 BMSlO Structural Properties of One of the "Keystone Beam Steel Floor" Constructions Sponsored by the H. H. Robertson Co 10(5 BMSll Structural Properties of the Curren Fabrihome Corporation's "Fabrihome" Constructions for Walls and Partitions 100 BMS12 Structural Properties of "Steelox" Constructions for Walls, Partitions, Floors, and Roofs

Sponsored by Steel Buildings, Inc 150 BMS13 Properties of Some Fiber Building Boards of Current Manufacture 100 BMS14 Indentation and Recovery of Low-Cost Floor Coverings 100 BMS15 Structural Properties of "Wheeling Long-Span Steel Floor" Construction Sponsored by

the Wheeling Corrugating Co 100 BMS16 Structural Properties of a "Tilecrete" Floor Construction Sponsored by Tilecrete Floors, Inc . 100 BMS17 Sound Insulation of Wall and Floor Constructions 100 Supplement to BMS17, Sound Insulation of Wall and Floor Constructions 50 BMS18 Structural Properties of "Pre-Fab" Constructions for Walls, Partitions, and Floors Sponsored by the Harnischfeger Corporation 100 BMSIO Preparation and Revision of Building Codes 150 BMS20 Structural Properties of "Twachtman" Constructions for Walls and Floors Sponsored by

Connecticut Pre-Cast Buildings Corporation 100 BMS21 Structural Properties of a Concrete-Block Cavity-Wall Construction Sponsored by the National Concrete Masonry Association 1 100 BMS22 Structural Properties of "Dun-Ti-Stone" Wall Construction Sponsored by the W. E. Dunn Manufacturing Co 100 BMS23 Structural Properties of a Brick Cavity-Wall Construction Sponsored by the Brick

Manufacturers Association of New York, Inc 100 BMS24 Structural Properties of a Reinforced-Brick Wall Construction and a Brick-Tile CavityWall Construction Sponsored by the Structural Clay Products Institute 100 BMS25 Structural Properties of Conventional Wood-Frame Constructions for Walls, Partitions,

Floors, and Roofs 150 BMS26 Structural Properties of "Nelson Pre-Cast Concrete Foundation" Wall Construction

Sponsored by the Nelson Cement Stone Co., Inc 100 BMS27 Structural Properties of "Bender Steel Home" Wall Construction Sponsored by the Bender Body Co 100 BMS28 Backflow Prevention in Over-Rim Water Supplies 100 BMS29 Survey of Roofing Materials in the Northeastern States 100 BMS30 Structural Properties of a Wood-Frame Wall Construction Sponsored by the Douglas

Fir Plywood Association 100 BMS31 Structural Properties of "Insulite" Wall and "Insulite" Partition Constructions Sponsored by The Insulite Co 150

[List continued on cover page iii]
UNITED STATES DEPARTMENT OF COMMERCE • Jesse H. Jones, Secretary

NATIONAL BUREAU OF STANDARDS • Lyman J. Briggs, Director

BUILDING MATERIALS

and STRUCTURES

REPORT BMS88

Recommended Building Code Requirements for

New Dwelling Construction

With Special Reference to War Housing

Report of Subcommittee on Building Codes

Central Housing Committee on Research, Design,

and Construction

ISSUED SEPTEMBER 25, 1 942

The National Bureau of Standards is a fact-finding organization;

it does not "approve" any particular material or method of construction. The technical findings in this series of reports are to be construed accordingly.

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • I942

FOR SALE BY THE SUPERINTENDENT OF DOCUMENTS, WASHINGTON, D. C. • PRICE 20 CENTS
Foreword

Building code requirements are frequently criticized on the ground

that they call for excessive amounts of materials and discourage the

introduction of new methods of construction. Such criticism is pointless unless improved requirements can be offered that will have

the effect of correcting the conditions mentioned. In this report a

representative committee, drawn from the Federal agencies most

concerned, with housing, presents its recommendations for such improved requirements. The intent is to assure safety and health and

at the same time permit the greatest possible flexibility in design and

construction. The recommended requirements cover single- and twofamily houses and multiple dwellings of limited height.

Lyman J. Briggs, Director.

[n]
Recommended Building Code Requirements

for

New Dwelling Construction

With Special Reference to

War Housing

Report of Subcommittee on Building Codes of the Central Housing Committee

on Research, Design, and Construction

Horace W. Peaslee, Chairman

(Secretary, Central Housing Committee)

Mary Fidelia Taylor, Secretary

George N. Thompson, Technical Adviser

(National Bureau of Standards)

Hollo H. Britten for C-E. A. WiNSLOw,

U. S. Public Health Service.

George R. Callis, Jr., Biu"eau of Yards and Docks (Navy).

TiRRELL J. Ferrenz and

Bruce E. Clark,

Federal Home Loan Bank Board.

Lx'THER M. Leisenring and

Charles M. Foster,

Office of Chief of Engineers (War).

William V. Eeed and

Ernest H. Olsen,

Division of Defense Housing Coordina,-

tion.

Bert M. Thorijd and

Louis Grandgent,

United States Housing Authority.

Howard P. Vermilya and

W. V. VanCott,

Federal Housing Administration.

Henry H. Waples,

Public Buildings Administration and

War Production Board.

ABSTRACT

A series of recommended requirements suitable for use in building codes is presented. These requirements

apply to single- and two-family houses and to multiple

dwellings of limited height. They cover such matters

as fire resistance, light and ventilation, exits, strength

of construction, and chimneys and fireplaces. In

general, good practice is required, certain well-recognized standards and specifications being cited as acceptable evidence of good practice. Specific dimensions

and other details are given where necessary. The

report contains an appendix in which additional in- formation is given, including methods of meeting

specific code provisions and references to source

material.

[1]
CONTENTS

Page

Foreword ii Introduction 6 Chapter I. General 7

Sec. 100. Scope 7

Sec. 101. Temporary permits 7

Sec. 102. Materials and methods not specifically authorized 7

Sec. 103. Second-hand materials 8

Sec. 104. Private water and sewage-disposal systems 8 Chapter II. Definitions 8 Chapter III. Fire-resistance classifications 11

Sec. 300. General 11

Sec. 301. Types of construction 11

1 . Fireproof 11

2. Incombustible 11

3. Exterior-protected 11

4. Wood-frame 12

Sec. 302. Doubtful classifications 12

Sec. 303. Partial compliance 12 Chapter IV. General building restrictions 12

Sec. 401. Zoning restrictions 12

Sec. 402. Limitations 12

1. Height 12

2. Area 12

3. Building lines 13

Sec. 403. Party walls 13 Chapter V. Light and ventilation 13

Sec. 500. General 13

Sec. 501. Rooms 13

1. Habitable rooms 13

(a) Minimum area 13

(b) Minimum height 13

(c) Minimum width 13

(d) Number of windows 13

(e) Rooms below finished grade 13

2. Bathrooms and water-closet compartments 13

3. Privacy 13

Sec. 502. Windows 14

1. Arrangement 14

2. Glass area 14

3. Openable area 14

4. Screening 14

Sec. 503. Ventilating skylights 14

Sec. 504. Yards 14

1. Rear yards 14

2. Side yards 14

3. Unobstructed 15

Sec. 505. Courts 15

1. Width 15

2. Area 15

3. Unobstructed 15

4. Drainage 15

5. Intakes 15

Sec. 506. Buildings on the same lot 15

Page

Chapter VI. Exits 15

Sec. 600. General 15

Sec. 601. Kinds of exits 15

Sec. 602. Number of exits 15

Sec. 603. Location 16

1. Distance 16

2. Distribution 16

Sec. 604. Stairways 16

1. Width 16

2. Construction 16

(a) Materials 16

(b) Treads and risers 16

(c) Landings 16

(d) Handrails 16

(e) Enclosures 16

(f) Lighting and ventilation__ 16

Sec. 605. Doorways 16

1. Width 16

2. Hanging of doors 17

Sec. 606. Public hallways 17

1. Width 17

2. Enclosure 17

3. Lighting and ventilation 17

Sec. 607. Modifications in exit width 17

Sec. 608. Obstructions 17 Chapter VII. Construction 17

Sec. 700. General 17

1. Quality of materials 17

2. Details and connections 17

3. Design and workmanship 17

Sec. 701. Working stresses 18

1. General 18

2. Increases 18

Sec. 702. Loads 18

1. Design 18

2. Floor, ceiling, and roof loads. 18

3. Wind loads 18

(a) Unit loads 18

(b) Anchorage 18

Sec. 703. Soil-bearing capacity 18

1. Normal conditions 18

2. Varying soil conditions -18

3. Filled ground 18

4. Clearing of building site 19

5. Protection of adjoining property 19

Sec. 704. Foundations 19

1. Required 19

2. Depth 19

3. Frozen ground 19

4. Footings 19

(a) Materials 19

(b) Design 19

5. Pile foundations 19

6. Foundation walls 20

(a) General 20

(b) Thickness 20

(c) Height above ground 20

[2]
Page

Chapter VII. Construction—Continued.

Sec. 704-6. (d) Waterproofing 20

(e) Drainage 20

Sec. 705. Masonry 20

1. Quality of materials 20

(a) Brick 20

(b) Structural clay tile 21

(c) Concrete masonry units __ 21

(d) Plain concrete 21

(e) Stone 21

(f) Gypsum block 21

(g) Mortar 21

2. Lateral support 22

(a) Solid masonry walls 22

(b) Walls of hollov/ units 22

(c) Cavity walls 22

(d) Methods 22

3. Solid brick walls 22

(a) Thickness—bearing 22

(b) Thickness—nonbearing _ _ 22

(c) Bond 22

4. Walls of hollow masonry units_ 22

(a) Thickness 22

(b) Bond 22

6. Plain concrete walls 22

(a) Thickness—bearing 22

(b) Thickness—nonbearing 23

(c) Reinforcement 23

6. Stone walls 23

(a) Thickness 23

(b) Bond 23

7. Hollow walls of solid units and

cavity walls 23

(a) Height 23

(b) Thickness 23

(c) Bond 23

8. Veneered masonry walls 23

(a) Materials 23

(b) Loading 24

(c) Attachment of veneer 24

9. Faced walls 24

(a) Materials 24

(b) Thickness 24

(c) Bond 24

10. Piers 24

(a) Height 24

(b) Size 24

(c) Hollow isolated piers 24

11. Openings in walls or parti- tions 24

12. Parapet walls 24

(a) Thickness 24

(b) Height 24

13. Spandrel walls 24

14. Partitions 25

(a) Bearing 25

(b) Nonbearing 25

15. Miscellaneous requirements- - 25

(a) Bonding at intersections ^ 25

(b) Chases and recesses 25

Chapter VII. Construction—Continued.

Sec. 705-15. (c) Lintels and arches 25

(d) Separation of combustible

structural members 25

(e) Concentrated loads 26

(f) Cornices 26

16. Existing walls 26

17. Erection 26

(a) Protection 26

(b) Support on wood 26

(c) Nailing blocks 26

Sec. 706. Reinforced concrete 26

1. General 26

2. Mix 26

3. Walls 26

(a) Anchoring 26

(b) Thickness 26

4. Protection of reinforcement- _ 26

(a) Footings 26

(b) Structural members 26

5. Protection 27

6. Working stresses 27

(a) Allowable stresses 27

(b) Increased stresses 27

7. Removal of forms 27

Sec. 707. Reinforced brick masonry 27

Sec. 708. Steel and iron 1 27

1. General 27

2. Working stresses 27

(a) Structural and rivet steeL 27

(b) Cast steel 28

3. Light steel construction 28

4. Steel joists 28

5. Miscellaneous requirements- _ 28

(a) Thickness 28

(b) Protection 28

Sec. 709. Wood construction 28

1. General 28

2. Determination of required

sizes 28

3. Working stresses 29

• 4. Posts 29

5. Splicing 29

6. Exterior walls 29

(a) Load-carrying capacity, _ 29

(b) Sheathing 29

(c) Masonry vcnccr on woodframe construction 29

(d) Stucco on wood-frame construction 29

(e) Ribbon boards 30

(f) Notching of studs 30

(g) Plates 30

(h) Framing over openings in bearing walls 30

(i) Jambs in bearing walls 30

7. Interior partitions 30

(a) Load-carrying capacity-- 30

(b) Plates 30

[3]
Page

Chapter VII. Construction—Continued.

Sec. 709-7. (c) Framing over openings in bearing partitions 30

8. Floors and roofs 30

(a) Joists and girders 30

(b) Headers and trimmers 31

(c) Support of rafters 31

(d) Bridging 31

9. Plank-and-beam construction. 32

(a) Design 32

(b) Beams 32

(c) Planl£ 32

(d) Exterior-wall framing 32

(e) Interior columns 32

(f) Fastenings 32

10. Wood houses with plywood

coverings 32

(a) Material 32

(b) Gluing plywood to framing members 32

(c) Design of flat panel with

stressed coverings 32

(d) Fastenings 33

11. Termites and decay 33

(a) Site of building 33

(b) Removal of debris 33

(c) Foundations 33

(d) Foundation wall vents 33

(e) Porches 33

(f) Selection of lumber 33

(g) Closeness to ground 33

(h) Girders in masonry or re- inforced-concrete walls. 33

(i) Floor sleepers 33

(j) Protection of material 33

(k) Expansion joints 33

(1) Water pipes 33 (m) Flashing over doors and

windows 33

(n) Moisture in walls 33 Chapter VIII. Fire protection 34

Sec. 800. General 34

Sec. 801. Fire separation 34

1. Between dwellings 34

2. Between dwelling units 34

3. Fire walls 34

4. Chimneys 34

5. Hazardous spaces 34

6. Garages 34

Sec. 802. Firestopping 35

1. General 35

2. Exterior walls 35

(a) Wood construction 35

(b) Furred spaces 35

3. Partitions 35

4. Stairs 35

5. Pipes or ducts 35

6. Sliding doors 35

7. Exterior cornices 35

8. Inspection 36

Page

Chapter VIII. Fire protection—Continued.

Sec. 803. Shafts 36

1. Enclosure required 36

2. Openings 36

3. Connections 36

Sec. 804. Roof coverings 36 Chapter IX. Chimneys and heating appliances. 36

Sec. 900. General 36

Sec. 901. Construction of chimneys 36

1. Materials 36

2. Foundations 37

3. Bonding 37

4. Corbeling of chimneys 37

5. Height 37

6. Concrete chimneys 37

7. Hollow masonry units 37

8. Solid concrete block 37

9. Stone 37

10. Flashing 37

11. Change of interior dimensions. 37

12. Special types of chimneys 38

Sec. 902. Flues 38

1. Flue lining 38

2. Separation 38

3. Construction 38

4. Area 38

5. Cleaning 38

Sec. 903. Fireplaces 38

1. Use of firebrick 38

2. Incombustible hearths 38

3. Fire prevention 39

(a) Removal of wood center- ing 39

(b) Clearances from combustible construction 39

Sec. 904. Smoke pipes 39

1. Connection with flue 39

(a) Connection required 39

(b) Number limited 39

(c) Thimbles 39

2. Passage through combustible

construction 39

(a) Ceilings, floors, roofs 39

(b) Partitions 39

3. Clearances from combustible

construction 39

Sec. 905. Mounting of heat appliances 39

1. General 39

2. Hearths.... 40

3. Clearances for stoves and

ranges 40

4. Clearances for gas ranges 40

5. Bases for heating furnaces 40

6. Clearances for heating fur- naces 40

Sec. 906. Ducts 40

1. Material 40

2. Protection 40

(a) Clearances from combustible construction 40

[4]
Page

Chapter IX. Chimneys—Continued.

Sec. 906-2. (b) Clearances within floors and partitions 41

3. Cold-air ducts 41

Sec. 907. Registers 41

1. Setting 41

2. Register boxes 41

3. One-pipe furnaces and floor furnaces 41

4. Fixed registers 41

Sec. 908. Mechanical circulation warm-air

sj^stems 41

1. General 41

2. Recirculation 41

3. Return ducts 42

Sec. 909. Steam and hot-water pipes 42

1. Clearances from combustible

construction 42

2. Pipe coverings 42

Sec. 910. Appliances 42

1. Gas appliances 42

(a) General 42

(b) Gas logs 42

(c) Gas-fired furnaces 42

(d) Water heaters 42

Ce) Venting 42

(f) Liquefied petroleum gases- 42

2. Oil-fired appliances 42

3. Steam and hot-water boilers.- 42

4. Automatic stokers 43

Sec. 911. Combustion 43 Chapter X. Safeguards against accidents 43

Sec. 1001. Stairways 43

Sec. 1002. Steps 43

Sec. 1003. Porches and terraces 43 Chapter XI. Electrical 43

Sec. 1100. General 43

Sec. 1101. National Electrical Code 43

Sec. 1102. Inspection 43 Chapter XII. Plumbing 43

Sec. 1200. General 43

Sec. 1201. Plumbing standards 43

Sec. 1202. Sanitary fixtures 43 APPENDIX*

Appendix 44

Par. 100. General 44

Par. 101. Temporary permits 44

Par. 102. Materials and methods not specifically authorized 44

Par. 104. Private water and sewage-disposal systems 44

Par. 300. Fire-resistance classifications 44

Par. 502. Windows 44

Par. 502-2. Glass area 44

Par. 502-4. Screening 44

Par. 606-3. Lighting and ventilation 44

Par. 700. Quality of materials 45

*For explanation of paragraph numbering, see Appendix, para- graph preceding par. 100.

Page

Appendix—Continued.

Par. 704. Foundations 45

Par. 704-4. Design of footings 45

Par. 705. Masonry 45

Par. 705-1. Quality of materials 45

Par. 705-15 (c). Lintels and arches 45

Par. 706. Reinforced concrete 45

Par. 707. Reinforced brick masonry 45

Par. 708. Steel and iron : 45

Par. 709-1. General 45

Par. 709-2. Determination of required

sizes 45

Par. 709-3. Working stresses 46

Par. 709-6 (a). Load-carrying capacity 70

Par. 709-6 (d). Stucco on wood-frame

construction 70

Par. 709-6 (h). Framing over openings in bearing walls 70

Par. 709-8 (b). Headers and trimmers 70

Par. 709-8 (c). Collar beams and tie beams 70

Par. 709-8 (d). Bridging 70

Par. 709-9. Plank-and-beam construction.. 70

Par. 709-10 (a). Material 71

Par. 709-10 (b). Gluing plywood to framing members 71

Par. 709-10 (c). Design of flat panel with

stressed coverings 71

(1) Construction features. 71

(2) Strength and stiffness. 71

Par. 709-11. Termites and decay 71

Par. 800. General 72

Par. 801. Fire separation 72

Par. 802-1. General 72

Par. 804. Roof coverings 72

Built-up roof coverings 72

Prepared roof coverings 73

Class 4 roof coverings 74

Class 5 roof coverings 74

Par. 900. General 74

Par. 901-12. Special types of chimneys 74

Par. 903. Fireplaces 74

Par. 908. Mechanical circulation warm-air

systems 74

Par. 910. Appliances 75

Par. 1000. Safeguards against accidents 75

Par. 1101. National Electrical Code 75

Par. 1201. Plumbing standards 75

Par. 1202. Sanitary fixtures 75

Rats 75 Noise 75

TABLES

1. Basic stresses for clear material 46

2. Working stresses for various lumber-association grades 48

3. Working stresses for various lumber-association grades of dimension 50

[5]
TABLES—continued

4. Maximum spans for floor joists of one- and two-story houses and of multiple

dwellings, 45 \h/W 52

5. Maximum spans for floor joists of multiple

dwellings, 55 Ib/ft^ 54

6. Maximum spans for ceiling joists, no stor- age, 10 lb/ft2 56

7. Maximum spans for ceiling joists, light storage, 30 Ib/ft^ 66

8. Maximum spans for roof joists and rafters, slopes 3 in 12 and less, not supporting

plastered ceiling, 20 Vo/W 58

8a. Maximum spans for roof joists and rafters, slopes 3 in 12 and less, not supporting

plastered ceiling, 30 Ih/W 58

9. Maximum spans for roof joists and rafters, slopes 3 in 12 and less, supporting

plastered ceiling, 20 Ib/ft^ 60

9a. Maximum spans for roof joists and rafters, slopes 3 in 12 and less, supporting plas- tered ceiling, 30 Ib/ft^ 60

10. Maximum spans for roof rafters, slopes

between 8]4 in 12 and 3 in 12, light roof- ing material, 20 \h/W 62

TABLES—continued

10a. Maximum spans for roof rafters, slopes

between 10y2 in 12 and 3 in 12, light

roofing material, 30 Ib/ft^ 62

11. Maximum spans for roof rafters, slopes Syi

in 12 and greater, light roofing material, 20 lb/ft2 64

11a. Maximum spans for roof rafters, slopes

10^2 in 12 and greater, light roofing material, 30 lb/ft2 64

12. Maximum spans for roof rafters, slopes

between 8>4 in 12 and 3 in 12, heavy

roofing material, 20 Ib/ft^ 66

12a. Maximum spans for roof rafters, slopes be- tween 10)4 in 12 and 3 in 12, heavy

roofing material, 30 Ib/ft^ 66

13. Maximum spans for roof rafters, slopes 8/2 in 12 and greater, heavy roofing material, 20 lb/ft2 68

13a. Maximum spans for roof rafters, slopes

10}^ in 12 and greater, heavy roofing

material, 30 Ib/ft^ 68 INTRODUCTION

The suggested building code requirements for

dwellings that appear in this report have been

prepared by a committee representing Federal

agencies concerned with various aspects of housing. The project was initiated at the suggestion of the Division of Defense Housing

Coordination which felt that such an undertaking would have an immediate value in

connection with problems gi'owing out of the

emergency and might be expected to carry its influence over into more normal times. It suggested that a committee of the Central

Housing Committee be established with in- structions to review the situation and adjust any

conflicting viewpoints on specific requirements.

The procedure employed in the work was

first to segTegate and compare typical existing

requirements, then to consider these in the light

of standards developed by the several housing

agencies and of information supplied by re- search, and finally to draft requirements repre- senting the composite judgment of the committee members. Many valuable suggestions were received from various governmental agencies. Standards of private agencies interested

in good construction also provided much helpful

material.

The committee recognizes that emergency

conditions limit the availability of certain

materials, require stringent economy in the use

of others, and make the use of substitutes neces- sary in some cases. It is of the opinion, however, that it is not practicable to write building

code requirements in terms of a severely restrict- ed list of materials based on temporary shortages nor to suggest details about substitutes in

the code itself. Such matters are covered more

flexibly and efficiently by general pi'ovisions in

the code, supplemented by regulations that can be put mto effect or withdrawn in accordance

with fluctuating conditions. Similarly, it has

been found best to treat the subject of new materials and methods of construction in a general

way, providing for acceptance on submittal of satisfactory evidence that they are suitable.

In general, the committee favors simplicity

of treatment where building code requirements

are presented. To this end, it has relied upon

references to many standards of public and

private agencies where inspection demonstrated that details were satisfactorily treated

in such standards. It has also presented as appendix matter various acceptable ways of meeting the code requirements in order to conserve space in the code itself and to widen the

field of choice of materials and methods.

[6]
I One point regarding these requirements deserves special emphasis. Such requhements can

I be legally effective only when they call for the

minimum that is necessary for safety and health.

This places them in a difl'crent class from other

standards, which properly take into consideration expected life, comfort, livability, good

taste, and other matters that are socially and

economically desirable but cannot be legally

i required. An appreciation of the distinction

' should help to clear up some of the confusion

I that exists regarding apparent inconsistencies

between building standards and building code

,1 requirements.

I The committee wishes to express its apprecia-

!| tion to the many governmental agencies that

j have responded freely to requests for informai tion and advice. Many individuals within the

organizations represented on the committee

j have been consulted on special problems and

have made very helpful suggestions. Special

1 aclmowledgment is made to the Forest Products

Laboratory of the United States Department of

? Agriculture and to the National Bureau of

\ Standards of the United States Department of

i| Commerce. Mention should also be made of

'j the close cooperation extended by other comI mittees of the Central Housing Committee, inI eluding those on Definitions, Design Standards,

I and Fire Resistance Classifications. The sugI gestions of the last-named committee have been

f especially helpful.

The report is presented as suitable for recom- mendation where advice is sought of Federal

agencies as to proper building code requirements in areas not now having such requirements. It is also offered for consideration

wherever local building code requirements are being adopted or revised. It is believed that

such a document can provide a continuing

service through which the experience of Federal

j agencies and the results of Federal research can

be made continuously available to local gov1 ernmental authorities. Periodical revision is planned; and criticism and suggestions for

j improvement are invited.

CHAPTER I. GENERAL*

Section 100. Scope

The requirements of this Code apply to dwellings hereafter erected, not over 2}^ stories

in height when containing 1 or 2 dwelling units,

and not over 2 stories in height when containing more than 2 dwelling units; and also to minor accessory structures, such as garages.

Section 101. Temporary Permits

It shall be unlawful to construct or add to a dwelling or other structure in violation of the

provisions of this Code; except that dwellings or other structures not conforming in all respects

to this Code may be approved by the building

official under a special permit issued by the

building official, authorizing him to require

their demolition or removal at the expiration of

1 year. Such permit may be extended for 1 additional year or for 1 year after the termination of a legally declared national emergency at the discretion of the building oflScial. For the

purpose of determining the adequacy of the

dwelling or other structure constructed under

such permit, the buUding official may accept the

certification of any Federal housing agency that

the dwelling or other structure is deemed adequate for its intended pui-pose and isneccssai-y

in the public interest. (See Appendix, par. 101 .)

Section 102. Materials and Methods not

Specifically Authorized

Materials and methods of construction not

specifically authorized by this Code may be

approved for use by the building official on

submittal of evidence satisfactory to him that

such use will result in safe construction at least equivalent to that required by this Code.^ ^ For

the purpose of determining safety, the building

*NOTE.—In municipalities and areas where there is no building code, it is recommended that the procedure concerning powers and duties of the building official, method of obtaining permits, and other administrative matters be governed by the proposed Administrative Requirements for Building Codes being developed by a committee of the American Standards Association, except as this procedure may be modified by tbis chapter. (See Appendix, par. 100.) See footnotes 1 and 2 on page 8.

466009°—42 2 [7]
official may require submittal of drawings,

methods of analysis, test data, or any other

information necessary to reach a decision.

Newly developed materials and methods of

construction for which specific requirements are not given in this Code shall not be used until

the buUding official has issued regulations fixing

the practices to be followed, but no such regulation shall have the effect of increasing the working stresses for any material mentioned in this Code or of reducing the fixe-resistive, fire- protective, or health features of the Code. (See

Appendix, par. 102.)

Section 103. Second-Hand Materials

Second-hand materials may be used provided

they comply in quality to requirements for materials in this Code. Masonry units shall be

thoroughly cleaned before reusing. Structural

members shall not be reused if so affected by

previous use as to impair their usefulness for the

purpose intended.

Section 104. Private Water and SewageDisposal Systems

Prior to occupancy, a certificate of inspection

to indicate compliance with acceptable requirements shall be obtained by the owner or his

agent from the State or local health official having jurisdiction in the case of all water and

sewage-disposal systems not municipally owned

and operated. Except as may be otherwise

provided in law, in this Code, or in duly promulgated regulations, the provisions of Parts I and

II of the Sanitation Code for State or Local

Adoption, of the United States Public Health

Service, shall be deemed to be acceptable practice. (See Appendix, par. 104.)

CHAPTER II. DEFINITIONS

For the purpose of this Code, the terms listed

below shall have the meanings given in this

chapter.

1 In addition to its general application, this provision will apply with

particular force during the war emergency to the use of substitute materials mentioned in the Defense Housing Critical List to take the place

of metals and other critical materials.

2 Attention is called to the fact that in the Administrative Require- ments for Building Codes referred to in the note at the foot of p. 7, provision is made for appeal to a board of appeals in case there is dis- satisfaction with the action of the oflBcial.

Alley means a narrow supplementary thor- ' oughfare for the public use of vehicles and \ pedestrians affording access to abutting property.

Approved, as applied to a material, device, : mode of construction, or testing agency, means

approved by the buUding official under the 1 provisions of this Code, or by other authority i designated by law to give approval in the matter ! in question.

Area, as applied to the dimensions of a buUd- { ing, means the maximum horizontal area of the

building at finished grade, exclusive of unroofed ; porches, terraces, steps, and areaways.

Basement means that portion of a buUding

between floor and ceiling partly underground,

but having less than half its clear height below

the adjoining finished grade. When 50 percent i or more of the floor area of a basement is I occupied for human habitation, it shall be

counted as a story.

Bearing partition. (See Partition, Bearing.)

Bearing wall. (See Wall, Bearing.) '| Building means an enclosed structure having ' exterior or party walls and a roof, designed for the shelter of persons, animals, or property.

Building official means the officer or other

person charged with the administration and

enforcement of this Code or his duly authorized

representative.

Cavity wall. (See Wall, Cavity.)

| Cellar means that portion of a building be- * tween floor and ceiling partly underground, but i having half or more than half of its clear i i. height below the adjoining finished grade. [| Common property line means a line dividing ^ one lot from another.

Concrete, Plain.—"Plain concrete" means \\ concrete cast in place without metal reinforcei ment or reinforced only for shrinkage or tem-

| perature changes.

| Concrete, Reinforced.—"Reinforced concrete" means concrete in which reinforcement, other \ ' than that provided for shrinkage or tempera- i ture changes, is embedded in such a manner

that the two materials act together in resisting

i forces. ' Court means an open, unoccupied space 1 bounded on two or more sides by the exterior ' walls of a building or by exterior waUs and lot < lines.
Court, Height.—"Height," as applied to a

court, means the vertical distance from the

level of the floor of the lowest story containing

habitable rooms served by that court to the

top of the walls bounding the court. In case

the tops of such walls are at different elevations,

the measurement shall be taken to the average

elevation of the two highest walls that are

opposite.

Court, Inner.—An "inner court" is a court

enclosed on all sides by exterior walls of a

building or by exterior walls and lot lines on

which walls are allowable.

Court, Length.—^" Length," as applied to an

outer court, means the mean horizontal distance

between the open and closed ends of the

court. Court, Outer.—An "outer court" is a court

enclosed on not more than three sides by

exterior walls of a building or by exterior walls

and lot lines on which walls are allowable, with

one side or end open to a street, driveway,

alley, or yard.

Court, Width.—"Width", as applied to an

inner court, means its least horizontal dimension. Width, as applied to an outer court, means the shortest horizontal dimension measured in a direction substantially parallel with

the principal open end of such court. Dead load. (See Load, Dead.)

Dwelling means a building designed or oc- cupied as the living quarters for one or more

families or households, usually equipped with

cooking, bathing, toilet, and, where necessary,

heating facilities. Dwelling unit means a dwelling or a portion

thereof providing complete living facilities for one family.

Faced wall. (See Wall, Faced.)

Fire-division wall. (See Wall, Fire-division.)

Fire door means a door construction consisting

of door, frame, and sill, which under approved

fire-test conditions meets the requirements for the location in which it is to be used.

Fire partition. (See Partition, Fire.)

Fire resistance means the period of resistance

to standard exposure under the standard fire

test. (See Appendix, par. 800.)

Fire wall. (See Wall, Fire.)

Grade.—"Grade," when used in connection

with lumber for structural piu-poses, is a classification with respect to strength and suitability

for use as a structural member.

Grade, Finished.—"Finished grade" means

the line formed at the junction of a building

and the area immediately surrounding the

building to which the ground is to be or has

been cut or filled. Grade, Natural.—"Natural grade" means the

surface of the ground prior to excavation.

Habitable room means a room occupied by one

or more persons for living, sleeping, eating, or

cooking, and includes kitchens serving a dwelling unit but does not include bathrooms, watercloset compartments, laundries, serving and

storage pantries, corridors, cellars, attics, and

spaces that are not used frequently or dxuing

extended periods.

Flalf story. (See Story, Half.)

Height, Building.—"Height," as applied to a

building, means the vertical distance from the

finished grade at the principal entrance of the

building to the highest point of such building

exclusive of chimneys, penthouses, parapets,

and ornamental features.

Height, Court. (See Court, Height.)

Height, Story.—"Height," as applied to a

story, means the vertical distance from the sur- face of a floor to the surface of the next floor above.

Height, Wall.—"Height," as applied to a

wall, means the vertical distance to the top

measured from the foundation wall, or from

a girder or other immediate support of the

wall. Hollow wall. (See Wall, Hollow.)

Incombustible.—"Incombustible," as applied

to a material, means that the material will not

of and by itself ignite when its temperature and

that of the surrounding air is 1,200° Fahrenheit

(649° C).

Lintel means a structural member supporting

masonry above an opening in a wall or partition.

Load, Dead.—"Dead load" means the weight

of walls, floors, roofs, partitions, and other per- manent portions of the structure. Lot means a portion or parcel of land considered as a unit, devoted to a certain use or

occupied by a building or a group of buildings

that are united by a common interest or use, and

the customary accessories and open spaces

belonging to the same.

[9]
Lot line means a line dividing one lot from

another, or from a street or other public space. Masonry means stone, brick, structural clay

tile, concrete masonry units, gypsum tile or block, structural glass block, or other similar

building tmits or materials, or a combination of

same, bonded together with mortar. Masonry

also includes plain concrete. Multiple dwelling means a dwelling containing

separate dwelling units for three or more families, with joint services or facilities or both.

Nonbearing partition. (See Partition, Nonbearing.)

Nonbearing wall. (See Wall, Nonbearing.)

Occupied shall be construed as though fol- lowed by the words "or intended, arranged, or designed to be occupied."

Panel wall. (See Wall, Enclosure.)

Partition, Bearing. "Bearing partition" means

a partition which supports any vertical load in

addition to its own weight.

Partition, Fire. "Fke partition" means a

wall or partition which subdivides a story of a

building to restrict the spread of fire or to provide an area of refuge.

Partition, Nonbearing. "Nonbearing partition" means a partition which supports no load

other than its own weight.

Party wall. (See Wall, Party.)

Pier means an isolated column of masonry;

a bearing wall not bonded at the sides into

associated masonry and whose length does not

exceed four times its thickness shall be considered a pier.

Plain concrete. (See Concrete, Plain.)

Property line, Common. (See Common property line.)

Reinforced concrete. (See Concrete, Reinforced.)

Room, Habitable. (See Habitable room.)

Shaft means an enclosed shaftway or space, extending through one or more stories of a

building, connecting a series of two or more

openings in successive floors, or floors and roof. Spandrel wall. (See Wall, Spandrel.)

Standardfire test means the fire-test procedure

formulated and published by the American

Society for Testing Materials under the title of "Standard Specifications for Fire Tests of Building Construction and Materials." (See

Appendix, par. 800.)

Story means that part of a building comprised

between a floor and the floor or roof next above

wherein 75 percent or more of the clear floor area has the minimum height established for habitable rooms. (See Basement.)

Story, Half.—A "half story" is one wherein

less than 75 percent of the clear floor area under

the roof next above has the minimum height

established for habitable rooms. An unflnished

space immediately under a roof of a multiple

dwelling shall not be considered a half story.

Street means a highway or thoroughfare

dedicated or devoted to public use by legal

mapping, user, or other lawful manner; and

includes avenue, road, alley, lane, boulevard,

terrace, concourse, driveway, and sidewalk.

Structure means a combination of materials

forming a construction having more or less permanent location.

Veneered wall. (See Wall, Veneered.)

Wall, Bearing.—A wall which supports any

vertical load in addition to its own weight.

Wall, Cavity.—A wall built of masonry units or of plain concrete, or a combination of these

materials, so arranged as to provide a continuous

air space within the wall from bottom to top,

and in which the inner and outer parts of the

wall are tied together with metal ties. Wall, Common-property-line.—A wall along a property line against which a wall can be built on the adjoining property.

Wall, Enclosure.—An exterior nonbearing wall

between cohunns or piers and supported at each story.

Wall, Faced.—A wall in which the masonry

facing and backing are so bonded as to exert common action imder load.

Wall, Fire.—A wall, whose strength is dependent upon incombustible materials, which

subdivides a building or separates buildings to

restrict the spread of flre, by starting at the

foundation and extending continuously through

all stories to or above the roof. Wall, Fire-division. —A wall which subdivides

a building to restrict the spread of fire, but is not necessarfly continuous through all stories nor extended through the roof. Wall, Hollow.—A wall built of solid masonry

units so arranged as to provide an air space

within the waU, bonding between separate

vertical withes being effected by the same

[10]
masonry units used in the wall construction so

; that the withes exert common action under load.

! Wall, Nonbearing.—A wall which supports no

vertical load other than its own weight.

Wall, Panel. (See Wall, Enclosure.)

Wall, Party.—A wall used jointly by two

parties under easement agreement and erected

at or upon a line separating two parcels of land

that may be held under different ownership.

Wall, Spandrel.—A part of a wall between the

top of a window or door of one story and the

sill of a window or door above.

I Wall, Veneered.—A wall having a facing

which is not attached and bonded to the backing

} so as to form an integral part of the wall for purposes of load bearing and stability.

Yard, Front.—A yard across the full width

of the lot, extending from the front line of the

building to the front line of the lot. Yard, Rear.—A yard across the full width of

; the lot, extending from the rear line of the buildI ing to the rear line of the lot.

I Yard, Side.—A yard extending from the

j front yard or front lot line to the rear yard or

rear lot line, from the side line of the building

to the side lot line.

j CHAPTER III. FIEE-RESISTANCE

CLASSIFICATIONS

II

I Section 300. General

For the purpose of this Code, construction

'I shall be classified into four different types which

' shall be limited as to height, ground-floor area, and location, and in other respects as required

i elsewhere in this Code. (See Appendix, par.

, 300.)

Section 301. Types of Construction

; 1. Fireproof

"Fireproof construction" means that in which

I structural members, including partitions, are of

J incombustible materials having a fire resistance

sufficient to withstand the fire severity resulting

i from complete combustion of the contents.

The minimum fire resistance of structural members shall be as follows:

Exterior walls—outside exposure: Distance from a common property line or other structures: Hours Under 10 feet (including commonproperty-line walls) 2 From 10 to 20 feet V/t More than 20 feet 1 Fire walls, fire-division walls, and party walls. _ 2

Fire partitions 1 Interior bearing walls 1 Columns, girders, trusses 1 Floor construction 1 Roof construction 1 provided that unprotected combustible or in- combustible roof construction may be used over an unusable attic space if the ceiling and the

construction below the attic are of incombustible

materials having a fire resistance not less than

that specified for floor construction.

Roof coverings shall conform to Class 1, Class 2, or Class 3 coverings if over incombustible sheathing, and to Class 1 or Class 2 coverings

if over combustible construction, as defined in

Section 804.

S. Incombustible

Incombustible construction is that in which

the exterior walls, bearing walls, floor and roof

construction, and other structural members are

of incombustible materials. Fire waUs shall have a fire resistance of at least 2 hours; party

walls and common-property-line walls shaU have

a fire resistance of at least Iji hours. Unprotected combustible roof construction and sheathing may be used over unusable spaces if protected beneath by a ceiling and supporting

construction of incombustible materials having

a fire resistance of at least }{, hour. Roof coverings shall conform to Class 1, Class 2, or Class 3, as defined in Section 804.

S. Exterior-Protected

Exterior-Protected construction means that

in which exterior walls are gi'ound supported

and of masonry or other incombustible construction. Interior framing is partly or wholly

of wood or other similar materials. The mini-

[11]
mum fire resistance of structural members shall be as follows:

Exterior walls—outside exposure: Distance from a common property line or other structures : Hows Under 10 feet 2 From 10 to 20 feet 1/

Over 20 feet 1 Party and common-property-line walls: At and below a framed first floor 2 Elsewhere IJ^ Fire walls: At and below a framed first floor 3 Elsewhere 2

Roof coverings shall conform to Class 1 or Class 2 when the dwelling or other structure is 12 feet or less from another building or other

structure or from a common property line. They shall meet requirements of Class 1, Class

2, or Class 3 when more than 12 feet from such

buildings, other structures, or lot lines.

4- Wood-Frame

Wood-Frame construction means that in

which exterior walls are wholly or partly of wood

or other combustible materials, including construction having an incombustible exterior veneer. Fire walls, party walls, and commonproperty-line walls shall have the following

minimum fire resistance:

Fire walls: Hows At and below a framed first floor 3 Elsewhere 2 Party and common-property-line walls: At and below a framed first floor 2 Elsewhere 1/

Roof coverings shall meet the requirements

of Class 1, 2, 3, or 4 in Section 804, provided

that when the dwelling or other structure is more than 12 feet from an adjacent dwelling

or other structure or from a common property

line, Class 5 roofing may be used.

Section 302. Doubtful Classifications

In case there is doubt as to the classification

within which a given dwelling or other structure

falls, the building official shall determine such

classification.

Section 303. Partial Compliance

Nothing in this Code shall require full compliance with a type of construction, if, under

this Code, a less restricted form of construction

is permitted; but no dwelling or other structure

shall be deemed to be of a given type of construction unless it conforms with all specific

provisions of this Code applying to that type.

CHAPTER IV. GENERAL BUILDING

RESTRICTIONS

Section 401. Zoning Restrictions

Nothing in this Code shall be construed to lower in any way existing zoning requirements.

If the requirements of this Code exceed existing

zoning requirements, then this Code shall govern.

Section 402. Limitations

1. Height \ No dwelling or other structure of Type 4

Wood-Frame construction shall exceed 40 feet or 2K stories at any point above finished grade, i

2. Area \ The ground-floor area of dwellings or groups

'

of attached dwellings of Type 2 Incombustible

or Type 3 Exterior-Protected construction

shall not exceed 4,500 square feet unless

j separated by fire walls into areas none of which ! exceeds 4,500 square feet. Within each area ; of 4,500 square feet there shall be not more than i 6 dwelling units: provided that in multiple i dwellings there shall be not more than 8 dwell- i ing units, 4 to a floor if the floor construction > between stories has a fire resistance of 1 hour. . The groxmd-floor area of a dwelling or of a i group of attached dwellings of Type 4 WoodFrame construction shall not exceed 3,000

square feet unless separated by fire walls into areas none of which exceeds 3,000 square feet. Within each ground-floor area of 3,000 square ^ feet there shall be not more than 4 dwelling

units.

Where a floor is over a basement or crawl

space and is of fireproof construction or where

it consists of a concrete slab laid on the ground,

[12]
the gToxmd-floor area and the number of dwelling units between fire walls, or either, may be

increased by 50 percent.

S. Building Lines

Except as specifically permitted in law or

regulations, no dwelling or other structure shall be so located that any part extends beyond

established building lines.

Section 403. Party Walls ^

Party walls shall be designed as bearing walls

capable of carrying safely any loads which may

be imposed from both sides; and shall be so constructed that a dwelling unit on either side

may be razed without impairment of structural

stability of the wall. (See ch. Ill and sec. 801-2.)

CHAPTER V. LIGHT AND VENTILATION

Section 500. General

For the purpose of providing adequate light

and ventilation, every building shall be constructed, arranged, and equipped to conform

to the provisions of this chapter.

Section 501. Rooms

1. Habitable Rooms

(a) Minimum area.—Living rooms shall have

an area not less than 150 square feet, or not

less than 160 square feet when dining space is included and not less than 220 square feet when

dining and cooking space is included, provided

that this area shall be not less than 210 square

feet when located in a dwelling unit having less than two bedrooms.

The area of kitchens shall be not less than 60

square feet, or not less than 90 square feet when

s The municipality or agency using this Code should examine the

statutes, ordinances, or other regulations pertaining to party walls in the community for correlation therewith. The recommendations in this Code incorporate only minimum requirements considered essential to health and safety to life. Some authorities contend that the mutuality

of ownership inherent in a party wall should impose additional construe

tion requirements. Presented below is the suggested wording for a code requirement based on this contention: Party walls shall be of masonry; they shall bear on foundations of the same type and construction as exterior wall foundations; they shall extend to the underside of the roof sheathing.

dining space is included, provided that the area

of the kitchen shall be not less than 50 square

feet when located in a dwelling imit having less than two bedrooms.

The area of at least one bedroom shall be not

less than 100 square feet. The area of any other habitable room shall be not less than 70 square feet. The minimum areas required above are exclusive of storage and closet space.

(6) Minimum height. —Habitable rooms shall have a clear height of not less than 7 feet 6 inches, provided that rooms in half stories shall have a clear height of 7 feet 6 inches in at least one-half their area. In computing the area of rooms in half stories, all portions less than 5

feet in height shall be disregarded.

(c) Minimum width.—Habitable rooms, ex- cept kitchens, shall be not less than 7 feet in width.

{d) Number oj windows.—Every habitable room shall have one or more windows conforming to the requirements of this chapter.

(e) Rooms below finished grade.—No room

which has less than 50 percent of its height

above the average adjoining finished grade

shall be occupied as a habitable room.

2. Bathrooms and Water-Closet Compartments

Every bathroom and every water-closet

compartment shall have one or more windows

or, when immediately under a roof, may have

a ventilating skylight, conforming to the re- quirements of this chapter.

S. Privacy

When a bathroom is provided, the following

requii-ements shall apply:

When there are several bedrooms, at least two bedrooms shall have access to a bathroom

without passing through another habitable room. Every bedroom shall have access to a bathroom without passing through another bed- room. Every habitable room shall have access

to every other habitable room without passing

through a bedroom.

No bathroom shall open directly into a

kitchen. No bathroom shall provide sole access

to any other room. No bathroom in a base-

[13]
ment shall serve as the only bathroom for a

living unit above.

Section 502. Windows

1 . Arrangement *

Every window required by this Code shall open directly on a street, alley, yard or court, or an approved open space equivalent to a yard

or court conforming to the requirements of this chapter.

The tops of windows providing requhed glass area shall be not more than 1 foot below the

finished ceilmg unless they are at least 7 feet

above the finished floor.

2. Glass Area

The aggregate glass area of windows or other

glazed openings requu-ed or permitted by this chapter shall be not less than the following (see

Appendix:, par. 502):

For habitable rooms, Ko of the floor area served by the windows or openings, but not

less than 12 square feet except for kitchens, which

shall have not less than 9 square feet (see

Appendix, par. 502-2)

For batlirooms and water-closet compartments, Yio of the floor area served, but not

less than 3 square feet; For basements and cellars, }io of the floor area served.

S. Openable Area ^

The aggxegate openable area of windows or other glazed openings required or permitted by

this chapter shall be not less than the following:

For habitable rooms, 50 percent of the

required glass area; For bathrooms and water-closet compartments, 50 percent of the required glass area, but

not less than 3 square feet; For basements and cellars, the entire re- quired glass area.

4. Screening

When deemed necessary by the local health

authorities, dwellings shaU be effectively

screened. (See Appendix, par. 502-4.)

* It is recommended that windows be so located as to provide as even a

distribution of light as possible throughout habitable rooms.

' It is recommended that consideration be given to requiring cross or through ventilation in aU dweUing units. (See Appendix, par. 502-2.)

Section 503. Ventilating Skylights

Skylights permitted by this chapter shall have

glass area not less than that required for windows they replace. They shall be arranged with

the sides extended above the roof and there

provided with hinged glazed sash having an

area not less than that required for openable

parts of windows, or they may be arranged with

fixed incombustible louvered sides having the

required openable area and a pivoted glazed

sash at the ceflmg line.

Section 504. Yards

1. Rear Yards

Every dwelling shall have a rear yard not less than 20 feet in depth. For each foot of height

that the wall located along the rear yard exceeds

15 feet above the average finished grade, the

depth of such yard shall be increased not less than 4 inches.

In the case of an irregular lot or where the

wall of a dwelling is not parallel to the lot line,

the required minimum depth of a rear yard may

be deemed to be the average depth (measured

perpendicular to the building wall), provided

that no such rear yard shall be less in depth

than 15 feet at any point. This minimum shall be increased 4 inches for each foot of height that

the wall located along the rear yard exceeds 15

feet above the average finished grade.

In computing the depth of a rear yard for any

dwelling when the rear of such yard opens on an

alley, one-half the width of such alley may be

assumed to be a portion of the yard.

2. Side Yards

Each side yard shall have a width of not less than 5 feet, provided that 4 inches shall be

added for each foot of height that the wall

located along the yard exceeds 15 feet above

the average finished grade.

In the case of an irregular lot or where a wall

of a dwelling is not parallel to the lot line, the

required minimum width of a side yard maybe

deemed to be the average width (measured

perpendicular to the wall of the dweUing), provided that no such side yard shall be less in

width than 3 feet at any point. This minimum

shall be increased 4 inches for each foot of

[14]
height that the wall located along the side yard

exceeds 15 feet above the average finished grade.

S. Unobstructed

Every yard shall remain unobstructed for its required width or depth and full height, except

that cornices projecting not more than 12 inches

into the required width or depth, ordinary

window sills or belt courses projecting not more than 4 inches into the required width or

depth, and drop awnings, shall not be considered obstructions. Clothes poles, arbors,

uncovered porches, steps, terraces, garden

trellises, and similar accessories are not prohibited by this requirement.

Section 505. Courts

1. Width

Every outer court serving habitable rooms

shall have a width of not less than 5 feet nor

less than 1 foot for each 3 feet or fraction

thereof in height.

Every inner court serving habitable rooms

shall have a width of not less than 10 feet nor

less than 1 foot for each 1 foot or fraction thereof

in height.

Courts shall not be deeper than twice their

width.

2. Area

The cross-sectional area of an inner court

serving habitable rooms shall be not less than

one and one-half times the square of its required

width.

3. Unobstructed

Every court shall remain unobstructed for

its required width or depth and full height,

except that cornices projecting not more than

12 inches into the required width or depth,

ordinary window sills or belt courses projecting

not more than 4 inches into the required width

or depth, and drop awnings, shall not be considered obstructions. Clothes poles, uncovered

porches, steps, terraces, arbors, garden trellises,

and similar accessories are not prohibited by

this requu'ement.

4- Drainage

The bottom of every court shall be properly

graded and drained.

466009°—42 3

5. Intakes

Every court that does not open for its full height on one or more sides on a street or yard

shall be connected at or near the bottom with a

street or yard by an intake. Such intake shall have a cross-sectional area of not less than 21

square feet and shall remain fully open at both

ends and unobstructed for its required size and

full length except that grilles, easily opened from

the approach side when the intake is used as an

exit, may be permitted at the ends.

Section 506. Buildings on the Same Lot

If any dwelling or other structure is placed on

the same lot with another building or other

structure so that any window of either receives

light and ventilation from the space between,

the width of such space shall be at least 10 feet. This minimum shall be increased not less than

4 inches for each foot that the wall located along

the space exceeds 15 feet above finished grade.

The height is to be taken as the average height

of the two structures.

CHAPTER VI. EXITS

Section 600. General

Multiple dwellings shall be provided with

exit facilities as provided in this chapter.

Section 601. Kinds of Exits

Exits shall consist of stairways or public

hallways and doorways providing direct exit to

a street or to an exterior open space leading to a

street. Exterior iron fire escapes shall not be

considered as required exits.

Section 602. Number of Exits

Every floor of a multiple dwelling and every

floor area enclosed by fire and exterior waUs

shall have not less than two exits ; provided that

when no entrance door of a dweUing unit is distant more than 20 feet from a door opening

into an exit stairway or from the top riser of such stairway, one exit may be permitted.

[IS]
Section 603. Location

1. Distance

Exits shall be so located that the distance

from the entrance door of a dwelling unit to an exit shall not exceed 60 feet; provided that no such door located on a dead-end hallway

shall be more than 20 feet from an exit.

2. Distribntion

When a floor has two or more exits, they shall be placed as far apart as practicable.

Section 604. Stairways

1. Width

No stairway serving as an exit shall have a width of less than 36 inches.

The aggregate width of stairways serving as

exits shall be not less than 22 inches for every

30 persons or fraction thereof served by the

stairway.^

2. Construction

(a) Materials.—Stairs and landings of stair- ways serving as exits shall be constructed of

incombustible materials, provided that combustible materials may be used in buildings of

Type 3 Exterior-Protected and Type 4 WoodFrame construction. Stairways shall have

solid treads.

(b) Treads and risers.—Treads and risers of

stairs in stairways serving as exits shall be so proportioned that the sum of two risers in

inches and the width of one tread in inches is not less than 24 nor more than 26, provided that no riser shall exceed 7% inches and no tread

shall be less in width than 9K inches exclusive

of nosing.

Winders shall not be used.

Treads and risers shall be of uniform width

and height in any one flight.

The minimum headroom of all required

stairways shall be 7 feet at every point measvired

vertically at the riser. The minimum number of risers in any flight

of a required stairway shall be not less than three.

(c) Landings.—No flight of stairs shall have a

' A suggested method of estimating the width of a required stairway is on the basis of 1)4 persons for each habitable room in each dwellingunit.

vertical rise of more than 12 feet between floors or landings.

The length and width of landings shall be not

less than the width of stairways in which they

occur.

(d) Handrails.—Required stairways shaU

have enclosing walls or well-secured balustrades or guards on both sides and shall be provided

with handrails on at least one side. When 44

inches or more in width, they shaU have handrails on both sides. Handrails shall project not more than 3^ inches into the width of the stair- way.

(e) Enclosures.—Required stairways and public hallways shall be enclosed with construction

having a fire resistance of at least % hour.

Stairways extending into basements and cellars shaU be provided with approved self-closing

metal-clad doors or with wood slab doors of a minimum thickness of 1% inches.

No openings except the necessary doorways,

and windows opening to the exterior of the

building, shall be permitted in enclosures of

stairways and hallways serving as exits.

(J) Lighting and ventilation.—Adequate facUities for artificial lighting shall be provided.

When dependence is placed upon natural

light, windows containing at least 12 square feet of glass area, or the equivalent of this in glass

block or glazed doors, shall be supplied; provided that a stairway of one continuous flight

may be lighted by a door on the entrance level

having a glass area of at least 10 square feet. Required stairways shall be provided with

ventilating skylights with fixed louvers, windows on an exterior wall glazed with plain glass, or a plain-glass skylight with a metal screen below the glass. The open or openable area in

the case of the first two devices shall be at least

6 square feet.

Section 605. Doorways

1. Width

No doorway serving as an exit shall have a

width of less than 32 inches.

The aggregate width of exit doorways to the

outside of a building from lobbies, hallways, or passageways into which exit stairways discharge shall be at least equal to the width of the

stairways.

[16]
The width of exit doorways at the foot of exit

stairways or at the head of exit stairways serving

basements shall be at the rate of not less than

20 inches for every 22 inches of stairway width

served.

^. Hanging of Doors

The doors of doorways serving as exits except

exterior doors shall swing in the direction of

exit travel and shall be so hung and arranged

that they shall not obstruct the travel along an exit passageway, stairway, or other required

exit, provided that a door swung flat against a

wall is not considered an obstruction and, provided further, that no door shall at any point in

its swing reduce the width of an exit stairway

by more than 18 inches.

No door of a doorway serving as an exit shall open immediately on a flight of stairs but a

landing at least the width of the door shall be

provided between such door and such stairs. Interior doors which provide access to or from a dwelling unit shall not be regarded as

exits. Section 606. Public Hallways

1. Width

The width of a public hallway shall be at

least equal to the width of the exit doorway to which it leads, but not less than 36 inches.

2. Enclosure

Walls, partitions, floors, and ceiling construction enclosing public hallways shall have a fire resistance of not less than that required for the

construction in which they occur but not less than 3/4 hour in any case.

3. Lighting and Ventilation

Adequate facilities for artificial lighting shall

I be provided. When dependence is placed on

natural light, windows or skylights containing

at least one-twentieth of the hallway floor area, or an equivalent area in glass blocks or glazed

I doors, shall be provided. (See Appendix, par. 606-3.)

Section 607. Modifications in Exit Width

There shaU be no reduction in required exit

width along the line of exit travel except as

specifically permitted in this chapter.

Section 608. Obstructions

No fire-extinguishing apparatus, radiator,

steam, or other riser shall be placed in an exit or in a hallway leading to an exit unless placed

in such a manner as not to interfere with free travel and unless heating apparatus is guarded

by substantial metal screens or is otherwise

safeguarded from contact with occupants.

CHAPTER VII. CONSTRUCTION

Section 700. General

1. Quality of Materials

All building materials shall be of good quality,

conforming to generally accepted standards.

Except as may be otherwise provided in law, or

in this Code, or in duly promulgated regulations,

the specifications of the American Society for

Testing Materials or other generally accepted

standards—such as Federal Specifications,

standards of the American Standards Association, or Commercial Standards promulgated by

the United States Department of Commerce

through the National Bureau of Standards

shall be deemed to be generally accepted

standards. (See Appendix, par. 700.)

B. Details and Connections

An members shall be so framed, tied, and

braced as to develop the strength and rigidity

necessary for the purposes for which they may

be used. No member shall be stressed in excess of the strength of its details and connections.

8. Design and Workmanship

Design of structural members, and workmanship in the fabrication and preparation of

materials and in their installation, shall con- form to generally accepted good practice.

Specific provisions of this section shall be controlling but shall not be deemed to suspend

other requirements of good practice which shaU

be regarded as supplementing such specific

provisions. Except as may be otherwise provided in law, or in this Code, or in duly promulgated regulations, the standards of Federal

or State agencies, national technical organiza-

[17]
tions, or fire underwriters shall be deemed to be

generally accepted good practice.

Section 701. Working Stresses

1. General

Dwellings and other structures shall be so designed that the safe working stresses of the

materials used are not exceeded.

2. Increases

Higher stresses than herein specified may be

used, but only if it is clearly established, by

test or other satisfactory evidence, that material

of a higher grade or a superior workmanship

than is generally provided in ordinary good

practice is to be employed. The use of higher

stresses, however, shall not be allowed until a statement, giving the reasons for such permission together with the facts and circumstances on which it is based, is placed on file and made

a part of the official record of the permit.

Section 702. Loads

1. Design

All parts of dwellings and other structures

shall be designed to support safely their own

weight and all other loads to which they may

be subjected.

2. Floor, Ceiling, and Roof Loads

The minimum load to be assumed as caused

by the occupancy for design of fioors shall be

not less than 40 pounds per square foot uniformly distributed, provided that, for upper

floors of single-family dwellings, the load may

be reduced to 30 povmds in designing floor joists for flexure. Where attics are to be used for light storage, a live load of not less than 20 pounds per square

foot shall be assumed on ceiling joists. Where

no provision is made for attic storage, no live load need be assumed on ceiling joists.

The total load to be used in designing girders

shall include the dead load of floor, ceiling, and

partition constructions plus the combined dead

and live load of the roof plus 50 percent of the

assumed live loads of floors and ceilings.

[

An imposed load of not less than 20 pounds

per square foot shall be assumed on roofs either

flat or pitched.'' This load shall be on the

horizontal projection.

3. Wind Loads

(a) Unit loads.—Vertical faces of dwellings

and other structiu-es shall be capable of withstanding a horizontal wind load of not less than

20 pounds per square foot, allowing for wind

from any direction.

Roofs or sections of roofs with slopes greater

than 30 degrees shall be capable of withstanding

a wind load of 20 pounds per square foot acting

inward normal to the surface, the load to be

applied to the windward slope only.

Where construction and provision for anchorage is satisfactory to the building official, submittal of design computations or test data may

be waived by him.

(b) Anchorage.—Adequate anchorage of roofs

to walls and columns, and of walls and columns

to foundations, shall be provided to resist safely

vertical lifting forces and to prevent any sliding or overturning.®

Section 703. Soil-Bearing Capacity

1. Normal Conditions

The safe carrying capacity of soil may be

assumed, for the purposes of this Code, as at

least 2 tons per square foot, provided that this i shall be modified where necessary in accordance

with rulings of the building official on the basis

of character and capacity of soil.

2. Varying Soil Conditions

In case a dwelling or other structure rests partly on rock or hardpan and partlj^ on some

other soil, measures shall be taken to equalize

settlement.

3. Filled Ground

No dwelling or other structure shall be placed

upon filled ground until the building official has

fixed by test or inspection the safe sustaining

power that may be assumed.

The load given is to be taken as the absolute minimum and should

be increased when necessary to take account of local conditions, including

loads caused by snow.

8 As a specific basis for design of anchorage, a suction or vertical lifting force of 20 pounds per square foot is suggested, assuming 2/3 of the dead load is acting to resist the force.

]
Jf.. Clearing of Building Site

All stumps and roots shall be removed from

the soil for a distance of 12 inches around and

beneath the space to be occupied by the dwelling

or other structure.

6. Protection oj Adjoining Property

Except as may be otherwise provided in law,

I excavations made to a depth of 12 feet or less

'I below natural grade shall be so protected that

the soil of adjoining property will not cave in

j or settle, but the expense of underpinning or

! extending the foundations of buildings or other

I structures on adjoining properties shall be borne

i by the adjoining property owner. For exca- vations ill excess of 12 feet below natural grade,

all expenses of any nature incurred by the

adjoining property owner in protecting his

; property shall be borne by the party causing

the excavation to be made.

Section 704. Foundations

1. Required

All dwellings or other structures shall have

foundation walls or piers, except when supj ported by concrete slabs whose design is approved by the building official.

2. Depth

Except when erected upon solid rock, foundation walls or piers shall be carried below frost

line and not less than 12 inches below natural

grade, provided that this requirement shall not

apply to structures other than dwellings which

are of Type 2 Incombustible or Type 4 WoodFrame construction not more than one story

in height and 400 square feet in area.

3. Frozen Ground

No dwelling or other structure shall be built

upon frozen ground.

4. Footings

(a) Materials.—Footings of walls, columns,

and piers shall consist of plain concrete,

reinforced concrete, or solid masonry units

when approved by the building official, provided that footings of wood may be used if

they are entirely below peiTnanent water level or subjected to a preservative treatment by

pressure processing confoiTning to good practice. Except as may be otherwise provided in

duly promulgated regulations, the recom- mendations of the American Wood-Preservers'

Association shall be deemed to be good practice.

(See Appendix, par. 704.)

(6) Design.—Footings of walls, chimneys,

piers, and columns shall be of dimensions to maintain a safe load on the soil and shall be so designed that the pressure on the soil per unit

of area shall, so far as practicable, be uniform

under all parts of the building or structure. Footings shall rest on level solid ground or rock.

Whenever excavation for footings is carried

below the planned depth, the space so excavated,

below the proposed footings, shall be filled solidly with concrete. The maximum projection of a footing shall be one-half of its depth

unless reinforcement is provided to resist bending. (See Appendix, par. 704-4.)

5. Pile Foundations

PUes intended to sustain walls or buildings

shall be of wood, reinforced concrete, steel

shells filled with concrete, or other approved

types. So far as practicable, they shall be

driven to a solid bearing; or they shall be

driven to provide adequate support in accord- ance with good engineering practice. The

method of driving shall be such as not to impair

their strength.

Wood piles shall be sound and straight

timber. Piles and capping timbers or portions

thereof, which are not placed below permanent

water level, shall be pressure-treated with

creosote in conformance with good practice.

Except as may be otherwise provided in duly

promulgated regulations, the recommendations

of the American Wood-Preservers' Association

shall be deemed to be good practice. (See

Appendix, par. 704.)

Piles and capping timbers or portions thereof

may not extend within 12 inches of the ground

surface. The safe sustaining power of wood

piles shall be determined by an approved for- mula or by test. When doubt exists as to the safe sustaining

power of pUes upon which a dwelling or other

[19]
structure is to be supported, the buUding

oj0B.ciaI may order a test to be made.

6. Foundation Walls

(a) General.—Foundation walls shall be of

sufficient strength and thickness to resist lateral pressure from adjacent earth and to support

their vertical loads safely.

(b) Thickness.—In no case shall a foundation

wall be less in thickness than the wall immediately above, provided that masonry veneered

walls may project not more than % inch beyond

the outside face of the supporting wall. When buUt of brick masonry, coursed stone,

structural clay tUe, or concrete masonry units, or when they are hollow walls of solid units,

foundation walls shall be not less than 12 inches

thick, provided that when such walls do not

extend more than 7 feet below the adjacent

ground level, or when the area within the

foundation walls is not excavated, walls may

be 8 inches thick if included within the allowable

height of 8-inch walls. When buUt of brick masonry reinforced with

at least one %-inch round deformed bar, con- tinuous from footing to top of foundation wall,

for each 2-foot length of wall, foundation walls

shall be at least 8 inches thick.

When buUt of concrete cast in place, foundation walls shall be at least 8 inches thick, or 6

inches thick for buildings or other structures not exceeding one story in height ; provided that

if such walls extend more than 7 feet below the

adjacent ground, they shall be reinforced in the same manner as described above for reinforced

brick masonry, or shall be increased in thickness

at least 1 inch for each additional foot of depth.

When buUt of rubble stone, foundation walls

shall be at least 16 inches thick. Rough or random rubble without bonding or level courses

shall not be used as foundations for walls ex- ceeding 35 feet in height.

When the character of soU makes it necessary,

the building official may require pilasters, buttresses, or additional wall thickness to guard

against the result of lateral pressure. He may

also require the installation of drain tile around

footings to cariy ground water away from the

structure.

(c) Height above ground.—Foundation walls

supporting wood or light steel structural members shall extend at least 6 inches above the

finished grade.

(d) Waterproofing.—Unless deemed unnecessary by the building official, foundation walls of basements and cellars shall be made watertight.

(e) Drainage.—When the surface of the

ground beneath a building having no basement

or cellar is below the outside finished grade,

adequate provision shall be made for draining

any space beneath the building.

Section 705. Masonry

1 . Quality of Materials ®

(a) Brick—Brick (clay or shale).—Brick

exposed to weather or soil, but not subject to

frost action when permeated with water, shall conform to the requirements for grade "MW"

brick of the Tentative Specifications for Building Brick (Made from Clay or Shale), ASTM

Designation C 62-4 IT of the American Society

for Testing Materials. When exposed to * weather or soil and subject to frost action when

permeated with water, brick shall conform to the

requirements for grade "SW". When not

exposed to weather or soU, brick shall conform

to the requirements for grade "NW".

Sand-lime brick.—Sand-lime brick exposed to weather or soil, but not subject to frost action

when permeated with water, shall conform to the

requirements for grade "MW" brick of the

Standard Specifications for Sand-Lime Building Brick, ASTM Designation C 73-39 of the

American Society for Testing Materials. When

exposed to weather or soU and subject to frost action when permeated with water, sand-lime

brick shall conform to the requirements for grade "SW". When not exposed to weather

or soU, sand-lime brick shall conform to the

requirements for grade "NW".

Concrete brick.—Concrete brick exposed to weather or soU shall conform to the requirements for grade "A" brick of the Standard

Specifications for Concrete Building Brick,

ASTM Designation C 55-37 of the American

Society for Testing Materials. When not

exposed to weather or soU, concrete brick shall

• See Appendix, par. 705.

[20]
conform to the requirements for grade "B"

brick.

(b) Structural clay tile.—Structural clay tUe used in party walls or exposed to weather or

soil shaU conform to the requirements for grade "LBX" tUe of the Standard Specifications for Structural Clay Load-Bearing Wall

Tile, ASTM Designation C 34-39 of the

American Society for Testing Materials.

Structural clay tUe used in load-beariQg

masonry but not exposed to weather or soU

shall conform to the requirements for grade

"LB" tile of the above specifications.

Structural clay tUe used in interior non-loadbeariag masonry shall conform to the requirements of the Standard Specifications for Structural Clay Non-Load-Bearing Tile, ASTM

Designation C 56-39 of the American Society

for Testing Materials.

(c) Concrete masonry units.—Hollow concrete masonry units used in party walls or in

load-bearing masonry or exposed to weather or

soil shall conform to the requirements of the

Standard Specifications for Hollow Load-Bearing Concrete Masoney Units, ASTM Designation C 90-39 of the American Society for Testing Materials.

Hollow concrete masonry units used in nonload-bearing masonry not exposed to weather

or soil shall conform to the requirements of the

Standard Specifications for HoUow Non-LoadBearing Concrete Masonry Units, ASTM

Designation C 129-39 of the American Society

for Testing Materials.

Solid concrete masonry units shall conform

to requirements of Tentative Specifications for Solid Load-Bearing Concrete Masonry Units,

ASTM Designation C 145-39T of the American Society for Testing Materials.

(d) Plain concrete.—Plain concrete other than

concrete fill shall have a minimum compressive

strength at 28 days of 2,000 pounds per square

inch.

The maximum size of concrete aggregates

shall be not larger than one-fifth of the narrowest dimension between forms of the member

for which the concrete is to be used, nor larger

than inches.

Water used in mixing concrete shall be clean,

and free from deleterious amounts of acids,

alkalis, or organic materials.

(e) Stone.—Stone for masonry shall be sound

and durable and free from clay and loose for- mations.

(J) Chjpsum block. —Gypsum block shall not

be used in walls exposed to the weather or to

soil.

(g) Mortar.—Mortars of the following proportions, with the sand measured in a damp

loose condition, shall be acceptable for the

specific uses mentioned in this section.

Type Proportions, by volume A 1 part of Portland cement to not more than

3 parts of sand, with an addition of hydrated

lime or lime putty of not more than 25 per- cent of the cement. B 1 part of Portland cement, 1 part of hydrated

lime or lime putty, and not more than 6 parts of sand.

1 part of prepared masonry cement conforming to Type II of Federal Specification

SS-C—181B to not more than 3 parts of sand. C 1 part of Portland cement, 2 parts of hydrated

lime or lime putty, and not more than 9 parts

of sand.

1 part of prepared masonry cement to not more than 3 parts of sand. D 1 part of hydrated lime or lime putty to not more than 3 parts of sand. Foundation walls below finished grade of

structural clay tUe or lioUow concrete masonry

units shall be laid in Type A mortar. Foundation walls below finished grade of solid masonry

units shall be laid in Type A or Type B mortar,

provided that Type A mortar shall be used when

exposed to frost in the presence of moisture.

Footings and piers shall be laid in Type A or Type B mortar, provided that Type A mortar

shall be used when exposed to frost in the pres- ence of moisture.

Load-bearing and exterior walls of structural

clay tUe or hollow concrete masonry units, and

load-bearing or exterior hollow waUs of masonry

shall be laid in Type A or Type B mortar.

Cavity walls not more than 10^2 inches in

thickness shall be laid in Type A mortar.

Cavity walls more than lOJ^ inches in thickness

shall be laid in Type A or Type B mortar.

Masonry linings of existing walls shall be

laid in Type A mortar.

For other masonry. Types A, B, or C mortar

may be used, provided that Type C shall not

be used where exposed to weather or soil.

[21]
Type D mortar of approved quality may be

used in solid masonry walls, other than parapet

walls, not in contact with the soil and not less than 12 inches thick, provided that the walls are

laterally supported at intervals not exceeding

12 times the wall thickness. (See Appendix,

par. 705-1.)

2. Lateral Support

(a) Solid masonry walls.—Solid masonry walls

shall be supported at right angles to the wall

face at intervals not exceeding 20 times the

wall thickness.

(6) Walls of hollow units. —Walls of struc- tural clay tUe or hollow concrete masonry units,

and hollow walls of masonry shall be supported

at right angles to the wall face at intervals not

exceeding 18 times the wall thickness.

(c) Cavity walls.—Cavity walls shall be supported at right angles to the wall face at intervals not exceeding 14 times the wall thickness

exclusive of the cavity.

(d) Methods.—Such lateral support may be

obtained by cross walls, piers, or buttresses,

when the limiting distance is measured horizontally, or by floors and roof when the limiting distance is measured vertically. Sufficient

bonding or anchorage shall be provided between the wall and the supports to resist the

assumed wind force, acting either inward or outward. Piers or buttresses relied upon for

lateral support shall have sufficient strength

and stability to transfer the wind force, acting

in either direction, to the ground. When walls are dependent upon floors or roofs for their

lateral support, provision shall be made in the

building to transfer the lateral forces to the

ground.

S. Solid Brick Walls

(a) Thickness—bearing. —Solid brick bearing

walls shall be not less than 8 inches thick if not

over 35 feet in height, provided that walls of

buildings or other structures not exceeding one

story in height may be 6 inches thick when built

with Type A mortar and not over 9 feet in

height. Walls of buildings more than 35 feet

in height shall be not less than 8 inches thick

for the uppermost 35 feet, below which they

shall be 12 inches thick.

(b) Thickness—nonbearing.—Solid brick nonbearing exterior walls shall be not less than 6 inches thick throughout theu* height.

(c) Bond.—In solid brick walls with a masonry bond, there shall be at least one fuU-length

header in every Iji square feet of wall surface,

provided that the distance between adjacent

full-length headers shall not exceed 20 inches

either vertically or horizontally. In walls more than 12 inches thick, the inner joints

of header courses shall be covered with another

header course which shall break joints with

the course below.

Where running bond is used, at least every

seventh course shall be a full header course or each face shall be bonded into the backing by

cutting the face-brick course and using diagonal

headers behind it or by using a split brick.

4- Walls of Hollow Masonry Units

(a) Thickness.—The minimuin thickness of

bearing and nonbearing walls of structural clay

tile or concrete masonry units shall be not less than that required for solid brick walls of cor- responding type.

(b) Bond.—HoUow masonry units shall have

fuU mortar coverage on vertical and horizontal

face shells. Where two or more hollow units are used to

| make up the thickness of a wall, the stretcher i courses shall be bonded at vertical intervals not

exceeding 34 inches by lapping at least 4 inches over the unit below.

j Where walls of hollow masonry units are : decreased in thickness, a course of solid masonry | shall be interposed between the wall section

below such point and that next above.

5. Plain Concrete Walls

(a) Thickness—bearing.—Plain concrete walls

shall be not less than 8 inches thick for a height

of 35 feet, provided that walls of buildings or other structures not exceeding one story in

height may be 6 inches thick when not over 9

feet in height. Walls of buildings over 35 feet

in height shall be not less than 8 inches thick for the uppermost 35 feet, below which they shall be 11 inches thick.

[22]
(6) Thickness—nonbearing

.

—Plain concrete nonbearing walls shall be not less than 6 inches

thick throughout their height.

(c) Reinforcement.—Reinforcement, symmetrically disposed in the thickness of the wall,

shall be placed not less than 1 inch above openings, and shall extend not less than 24 inches

each side of such openings or be of equivalent

length with hooks. The reinforcement shall consist of two %-inch round rods for openings

up to 5-foot spans, with two additional ^-inch

round rods for openings up to 8-foot spans, or

their respective equivalents.

At wall junctions or returns two %-iiich roimd

rods or their equivalent, bent to the angle of

the junction, not less than 12 inches long each

side of the bend, shall be spaced not over 20

inches apart in the height of the wall, symmetrically disposed, with at least 1 inch of concrete covering the steel.

6. Stone Walls

(a) Thickness.—The minimum thickness of

walls of stone ashlar shall be not less than that

required for solid brick walls. Rubble stone walls shall be 4 inches thicker

than is required for solid brick walls of the same

respective heights, but in no case less than 16

inches.

(b) Bond.—Bond stones extending through

the wall and uniformly distributed shall be

provided to the extent of not less than 10 per- cent of the area, and there shall be at least one bond stone for every five stretchers.

7. Hollow Walls of Solid Units and Cavity Walls

(a) Height.—Hollow walls of solid masonry

units and cavity walls shall not exceed 35 feet

in height above the tops of foundation walls.

(6) Thickness.—The minimum thickness of

hollow walls of solid masonry imits shall be not

less than 8 inches.

The minimum thickness of cavity walls, exclusive of the cavity, shall be not less than that

required for walls of the material which forms

the inner part of the wall, with a tolerance of

K inch. Cavity walls formed of two nominal

4-inch withes shaU not exceed 25 feet in height.

Neither the outer nor the inner part of a cavity

wall shall be less than 3% inches thick, and the

distance between inner and outer parts of the

wall shall be not less than 2 inches nor more

than 3 inches.

(c) Bond.—The inner and outer parts of

hollow walls of solid masonry units shall be

securely tied together with headers so that the

parts of the wall will exert common action under

the load, but in no case shall there be more than

4 courses of masonry imits when laid on edge, nor more than 6 courses when laid flatwise,

between header courses. Where hollow walls of solid masonry units are decreased in thickness, a course of solid masonry

shall be interposed between the wall section

below such point and that next above.

The inner and outer parts of cavity walls

shall be securely tied together with suitable

bonding ties of adequate strength. Ties shaU be

steel rods coated with portland cement grout

or other approved protective coating, or a noncorroding metal. A ^{e-inch diameter steel rod

or its equivalent shall be used for each 3 square

feet of waU surface. The ends of the ties shall be bent to 90-degree angles to provide hooks not

less than 2 inches long and shall be embedded

in a horizontal joint of each withe.

For walls constructed of hollow units, ties shall consist of bars bent to the shape of a

rectangle with the ends butted (not welded) on one side and lying in the mortar bed of the

withe with each end of the tie lying over at

least one web of units; or they shall consist of

welded steel wire in strips of two longitudinal

wires lying in mortar beds of both withes and

cross wire equivalent to the ties specified for rectangular shapes.

Additional bonding ties shall be provided at

all openings, spaced not more than 3 feet apart

around the perimeter of the opening and within

12 inches of the edge of the opening. Cavity

walls shall be flashed so as to lead moisture to the outside through weep holes provided for the

purpose. Cavity walls of plain concrete shall be reinforced as provided in Section 705-5 (c).

8. Veneered Masonry Walls

(a) Materials.—Materials xised for veneering

shall be not less than 3 inches in thickness,

466009°—42- [23]
provided that thinner material may be used

when approved by the building official. In stone ashlar, each stone shall have a

reasonably uniform thickness, but all stones need not necessarily be of the same thickness.

(b) Loading.—In no case shall veneering be

considered a part of the required thickness of

bearing walls.

(c) Attachment oj veneer.—The veneering

shall be tied into the backing either by a header for every 300 square inches of wall

surface or by substantial, noncorrodible metal

wall ties spaced not farther apart than 1 foot

vertically and 2 feet horizontally. Headers

shall project at least 3% inches into the backing.

When veneering is used, special care shall be

taken to fill all joints flush with mortar around

openings. Slab terra cotta, flat tile, or other

thin veneering shall also be solidly cemented to the masonry backing.

9. Faced Walls

(a) Materials.—Materials used in the backing

and facing of faced walls shall conform in aU

respects to the requirements prescribed for such materials in Section 705-1. Materials

used for facing shall be not less than 2% inches

thick, and in no case less in thickness than %

the height of the unit.

(b) Thickness.—Faced walls shall be not less in thickness than is required for masonry walls

of the type which forms the backing.

(c) Bond.—Brick facing shall be bonded to walls of brick, of structm-al clay tile, or of concrete masonry units, with at least one full-length

header in every l}^ square feet of waU surface.

Stone ashlar facing shall have at least 20 per- cent of the superficial area not less than 3%

inches thicker than the remainder of the facing

to form bond stones, which shall be uniformly

distributed throughout the wall. When some stones in every alternate course

are at least 7K inches thick, bonded into the

backing at least 3% inches, and at least 20

percent of the superficial area of the waU is constituted of such bond stones uniformly dis- tributed, the ashlar facing may be counted as part of the wall thickness. Every stone not a bond stone and every projecting stone shall be

securely anchored to the backing with substantial noncorrodible metal anchors with a cross

section of not less than 0.2 square inch or other approved anchors. There shall be at

least one anchor to each stone and not less than

two anchors for each stone more than 2 feet in

length and 3 square feet in superficial area. Facing stones not over 12 square feet in area

shall have at least one anchor to each 4 square

feet of superficial face area.

10. Piers

(a) Height.—The unsupported height of piers

shall not exceed 10 times their least dimension.

(6) Size.—Piers shall be not less than 8 inches

by 16 inches or 12 inches by 12 inches for unit

masonry and not less than 10 inches by 10

inches or 12-inch diameter for plain concrete.

(c) Hollow isolated piers.—Structm-al clay

tile or hollow concrete masonry units shall not

be used for isolated piers to support girders or beams unless solidly filled with concrete, but no increase in loading shall be permitted be- cause of such filling; provided that unfilled

hollow piers may be used if their unsupported

height is not more than 4 times their least dimension. Unfilled hoUow piers shall be built

solid at their tops to a depth of at least 4 inches

unless they support concrete slabs.

11. Openings in Walls or Partitions

Openings shall not be permitted in walls or

partitions separating dwelling units.

12. Parapet Walls

(a) Thickness.—Parapet walls shall be at

least as thick as the top-story walls which support them, except that they need not in any

case be more than 8 inches thick.

(b) Height.—Parapet walls shall be at least 6 inches high, but shall be not higher than 4

times their thickness unless laterally supported.

When reinforced both horizontally and vertically with not less than %-inch rods spaced

not more than 2 feet on centers, the height of

parapet walls may be not more than 6 times

their thickness.

13. Spandrel Walls

Spandrel walls shall be not less in thickness

than that required for nonbearing walls of the

[24]
kind of material used, provided that this

thickness may be reduced to 4 inches when

backed with % iach of incombustible iasulatiag

material.

14- Partitions

(a) Bearing.—All interior bearing walls, ex- cept fire walls and fire-division waUs, are considered as bearing partitions.

j Bearing partitions shall be of sufficient thickI ness to support their vertical loads safely, but

not less than as required in Section 705-2.

(b) Nonbearing.—Nonbearing partitions of

I masonry shall be built solidly against floor and

ceiling construction below and above, and the

thickness, exclusive of plaster, shall be not less than 2 inches for a maximmn unsupported height

of 9 feet; provided that nonbearing masonry

I partitions having an unsupported height greater

] than 9 feet and not more than 12 feet, shall be

I 3 inches thick exclusive of plaster.

IS. Miscellaneous Requirements

(a) Bonding at intersections.—Masonry walls

j shall be securely anchored and bonded at points

I where they intersect and where they abut or join

the frame of a skeleton-frame building.

Cast-in-place concrete slabs bearing on masonry walls shall be considered as sufficient

anchorage for the supporting walls.

(b) Chases and recesses.—There shall be no

chases in walls that are 8 inches or less in thick- ness or within the required area of any pier;

and no chase in any wall or pier shall be deeper

than one-third the wall thickness, provided that a chase not exceeding 4 inches wide and 4 inches

deep may be built for a height of 8 feet into an

8-inch wall of a single- or two-family detached

or semidetached dwelling if any space not otherwise occupied is filled with incombustible insulating material. No horizontal chase shall ex- ceed 4 feet in length, nor shall the horizontal

projection of any diagonal chase exceed 4 feet

in length.

Recesses for radiators and similar appliances

may be built into a wall, provided the wall is not reduced below 4 inches in thickness and is backed with ^ inch of incombustible insulating

material.

Except as permitted above, no chases or re- cesses shall be permitted in any wall that will reduce the fire resistance of such wall below the

minimum specified in this Code.

The aggregate area of recesses and chases in

any wall shall not exceed one-fourth the whole

area of the face of the wall in any story.

Chases and recesses shall not be cut in solid

8-inch walls or in hollow walls, cavity walls, or walls of hollow masonry units, but may be

built in.

(c) Lintels and arches.—The masonry above

openings and recesses shall be supported by

arches or lintels of steel or of plain or reinforced

masonry, which shall bear ort the wall at each

end for not less than 4 inches and shall be supported as required for concentrated loads.

Stone or other nonreinforced masonry lintels shall not be used unless supplemented on the

inside of the wall with iron or steel lintels or with

suitable masonry arches carrying the masonry

backing.

Steel or reinforced masonry lintels shall be of

sufficient strength to carry the superimposed

load without deflection of more than one threehundred-sixtieth of the clear span.

Masonry arches shall be designed to carry

the superimposed load. Proper provision shall be made for resisting lateral thrust. (See

Appendix, par. 705-1 5(c).)

(d) Separation of combustible structural members.—A separation of at least 4 inches of solid

masonry shall be provided in all walls between

combustible members which may enter from

opposite sides. When unprotected-steel or combustible structural members frame into hoUow walls of thick- ness not greater than 12 inches, they shall project not more than 4 inches into the wall

and shall be so spaced that there shall be a dis- tance of at least 4 inches between the ends of

such members entering from opposite sides of

the wall. The space above, below, and between

such members shall be filled solidly with burntclay materials, mortar, concrete, or equivalent

fire-resistive material, to a depth of not less than

4 inches on all sides of the members.

All open cells in tiles or blocks occurring at wall ends shall be filled solidly with concrete

for a depth of at least 6 inches, or closm-e tiles set in the opposite direction shall be used.

1251
(e) Concentrated loads.—Beams, joists, girders,

and other structural members producing con- centrated loads on walls or piers shall have bearings at least 3 inches in length upon solid masonry

not less than 4 inches thick. Metal bearing

plates of adequate design and dimensions, but

not less than %6 inch thick, may be used.

(/) Cornices.—The centers of gravity of

stone cornices shall be inside the outer wall

face. Terra-cotta or metal cornices shaU be

structurally supported.

16. Existing Walls

No existing wall shall be used for renewal or extension of a building, or be increased in height,

without special written permission from the

building official.

17. Erection

(a) Protection.—All masonry shall be protected against freezing for at least 48 hours

after placing. Unless adequate precaiitions

against freezing are taken, no masonry shall be

built when the temperature is below 32 degrees

Fahrenheit on a rising temperature or below 40

degrees on a falling temperature, at the point

where the work is in progress. No frozen

materials shall be built upon. In hot dry

weather, adequate precautions shall be taken to prevent too rapid drying.

(b) Support on wood.—No masonry wall construction shall be supported on wood girders or other form of wood construction.

(c) Nailing blocks.—No timber, except nailing blocks not exceeding an ordinary brick in

size, shall be built in as a part of masonry walls;

but this shall not preclude the use, on exterior

walls, for decorative purposes only, of timber

members against the masonry or set into the

masonry to no greater extent than permitted

in this Code for chases.

Section 706. Reinforced Concrete

1. General

Except as may be otherwise provided in law,

in this section, or in duly promulgated regulations, the Building Regulations for Reinforced

Concrete of the American Concrete Institute

as adopted and amended from time to time shall be deemed to be generally accepted good practice. (See Appendix, par. 706.)

2. Mix

Concrete for reinforced concrete shall consist

of 1 part of Portland cement to not more than 6

parts of aggregate, either in the proportion of 1 part of cement, 2 parts of sand, and 4 parts of coarse aggregate measured dry by volume, and

not more than 7}^ gallons of water per sack of

94 pounds of cement ; or in such other proportion

that the crushing strength at 28 days shall be

not less than 2,000 pounds per square inch.

S. Walls

(a) Anchoring.—Enclosure walls of reinforced

concrete shall be securely anchored at all floors. Such walls when supported by girders at each

story shall be bonded or otherwise securely tied to columns or piers.

(6) Thickness.—Bearing walls shall be not less than 6 inches in thickness for the uppermost

12 feet of their height and shall be increased

1 inch for each successive 25 feet or fraction

thereof measured downward. They shall have

a thickness of at least one twenty-fifth of the

unsupported height or length, whichever is the j; shorter, provided that approved buttresses,

built-in colunms, or piers designed to carry all the vertical loads may be used in lieu of increased

thickness.

Panel and enclosure walls shall have a thick- ness of not less than 5 inches and not less than

one-thirtieth the distance between the supporting or enclosing members.

Exterior basement and cellar walls, foundation walls, and fire walls shall be not less than

8 inches thick, provided that foundation walls

of one-story buildings may be 6 inches.

4- Protectio7i of Reinforcement

(a) Footings.—The reinforcement in footings

shall be covered on all sides by not less than 3 inches of concrete wherever such footings come in contact with the ground.

(6) Structural members.—The reinforcement

in columns, girders, and beams shall be covered on all sides by not less than l}{ inches of concrete.

[26]
5. Protection

When the temperature of the surrounding

air is less than 40° Fahrenheit, the concrete

shall be heated and protected for as much time

as is necessary to insure proper curing. In hot

dry weather, adequate precautions shall be

taken to prevent too rapid drying.

6. Working Stresses

(a) Allowable stresses.—For concrete of the

grade provided for in this section the workiiig

stresses, in pounds per square inch, in reinforced concrete construction shall be taken as follows: Extreme fiber of concrete, in compression

(flexure) 900

Concrete in direct compression 500

Concrete in shear i__ 40

Bond between concrete and steel 80 Bond between concrete and approved de- formed bars 100 For steel reinforcement, in tension:

Intermediate and hard grade 20, 000

Structural grade 18, 000 Cold-drawn steel wire '° 20, 000

(b) Increased stresses.—When evidence ac- ceptable to the building official is submitted that

the concrete or reinforcing steel to be provided

ji will be of greater unit strength, the above work1 ing stresses may be increased in accordance with

I generally accepted good practice. (See sec.

li 706-1.)'

7. Removal of Forms

Forms for reinforced concrete shall remain in

place until the concrete has hardened. Those

|! parts of the forms and shoring that support

structural members shall not be removed until

: such members have acquired sufficient strength

I to support safely their own weight and such

loads as may come upon them during construction operations. All forms and other temporary

woodwork which are near to or in contact with

the concrete or the soil shall be removed when

the construction is completed.

Section 707. Reinforced Brick Masonry

Reinforced brick masonry shall conform to generally accepted good practice. Except as may be required in law, in this Code, or in duly

promulgated regulations, the requkements of

May be increased to 30,000 under conditions specified in Building Regulations for Reinforced Concrete of the American Concrete Institute.

Chapter 13 of Principles of Brick Engineering,

1939, published by Structural Clay Products

Institute, shall be deemed to be generally ac- cepted good practice. (See Appendix, par. 707.)

All mortar for reinforced brick masonry shall be Type A. (See sec. 705-1 (g).)

Section 708. Steel and Iron

1. General

Except as may be otherwise provided in law, in this section, or in duly promulgated

regulations, the Specification for the Design,

Fabrication and Erection of Structural Steel

for Buildings of the American Institute of

Steel Construction shall be deemed to be

generally accepted good practice. (See Appendix, par. 708.)

2. Working Stresses

(a) Structural and rivet steel.-—Working

stresses, in pounds per square inch, for structural steel shall not exceed the following values:

Tension:

Structural steel, net section 20, 000

Rivets, on area based on nominal diameter. 15, 000

Compression:

Columns, gross section For axially loaded columns with

values of l/r not greater than

p

120 17, 000-0. 485

For axially loaded columns with IS^.^^^., values of l/r greater than 120_ ^^ 18 000 r" in which I is the unbraced

length of the column and r

is the corresponding radius

of gyration of the section,

both in inches. Plate girder stiffeners, gross section 20, 000

Webs of rolled sections at toe of fillet 24, 000

Bending:

Tension on extreme fibers of roUed sections, plate girders,

and built-up members 20, 000

Compression on extreme fibers of rolled sections, plate girders,

and built-up members, for values of l/h not greater than '-^ 40 1+

j^gQQ

with a maximum of 20, 000

in which I is the laterally

unsupported length of the member, and b is the width of the compression flange, both

in inches. Stress on extreme fibers of pins 30, 000

[27]
Shearing:

Rivets . 15, 000

Pins, and turned bolts in reamed or drilled holes 15, 000

Unfinished bolts 10, 000

Webs of beams and plate girders, gross

section 13, 000 „ . Double Single Hearing: shear shear Rivets 40, 000 32, 000

Turned bolts in reamed or

drilled holes 40, 000 32, 000

Unfinished bolts 25, 000 20, 000

Pins 32, 000 Contact area: Milled stiffeners and other

milled surfaces 30, 000

Fitted stiffeners 27, 000

Expansion rollers and rockers (pounds per linear inch) QOOd

in which d is diameter of roller or rocker in inches.

(b) Cast steel.—Compression and bearing same as for structural steel. Other allowable

stresses, 75 percent of those for structural steel.

3. Light Steel Construction

Steel studs, or other steel structural members

of hot-rolled or cold-formed steel, other than

steel joists, having less thickness than called

for in the specifications referred to in Section 708-1 may be used either alone or in

combination with other materials provided

they are designed in accordance with generally

accepted good practice and are capable of supporting all loads, including wind loads,

without exceeding allowable working stresses. Working stresses for members of steel equal in

quality to structural steel shall be the same as

for that material. For members of steel differ- ent in quality, working stresses shall be modified as required by the buUding ofiicial. (See

Appendix, par. 708.)

4- Steel Joists

Except as may be otherwise provided in law,

in this section, or in duly promulgated regulations, the Standard Specifications for Steel

Joists of the Steel Joist Institute shall be

deemed to be generally accepted good practice

for design and installation of steel joists. When

required by the building official, design computations, test results, or other information

shall be supplied sufficient to establish the

safety of the construction. (See Appendix

par. 708.)

Field welding shall be done only when

approved by the building official. (See Appendix, par. 708.)

5. Miscellaneous Requirements

(a) Thickness.—The minimum thickness of

all steel members in exposed places, including

crawl spaces, shall be not less than 16 gage.

(6) Protection.—Steel studs, joists, and all other steel members shall be given one shop

coat of approved paint. All exposed members

shall be given a second coat in the field.

Section 709. Wood Construction

1. General

All wood structural members shall be of

sufficient quality, size, and strength and so conditioned and used as to carry their imposed

loads safely and without exceeding the allowable working stresses specified in this section.

Except as may be otherwise provided in law,

in this section, or in duly promulgated regulations, the principles set forth in the Wood

Handbook of the United States Departm^ent of

Agriculture shall be deemed to be good practice

in the design of wood construction.

Adequate nailing shall be provided at the

intersections of wood structural members and

at other points specifically designated in this section. (See Appendix, par. 709-1.)

2. Determination of Required Sizes

Unless otherwise designated, the sizes given

in this section are nominal. American Lumber

Standard dressed sizes shall be accepted as the

minimum net sizes conforming to nominal

sizes." Computations to determine the required

sizes of members shall be based on the net

dimensions (actual sizes) and not the nominal

sizes. If rough sizes or finished sizes exceeding

American Lumber Standard dressed sizes are to be used, computations may be predicated on

such actual sizes, provided they are specified

11 See Simplified Practice Recommendation RlG-39, Lumber: American Lumber Standards for Softwood Lumber, promulgated by the U. S. Department of Commerce through the National Bureau of Standards. (See Appendix, par. 709-2.)

[28]
on the plans, or in a statement appended thereto.

For convenience, nominal sizes may be shown

i on the plans.

S. Working Stresses

The allowable working stresses for all species

and grades shall be based on evaluation of the

j effect of knots, and on the limitations of decay,

I slope of grain, shakes, checks, splits, wane, and

j moisture content, in accordance with the prin-

\ ciples set forth in Miscellaneous Publication

185, Guide to the Grading of Structural Timi bers (February 1934), of the United States

Department of Agriculture, and May 1940

' Supplement thereto issued by the Forest

j Products Laboratory. (See Appendix, par.

I 709-3.)

Working stresses due to the dead and live loads, acting singly or in combination, but

! without wind or other loads of short duration,

; shall not exceed the allowable stress permitted

! for the respective species and grade. For

stresses produced by wind or other lateral loads

of short duration or by combination of wind

loads and dead and live loads, the allowable

,j stresses herein permitted may be increased 50

j percent, provided the resulting sections are not

I less than those required for dead and live loads

alone. The values for modulus of elasticity shall be taken without change under any condition of load.

Shearing stress for joint details may be taken

as 50 percent greater than the horizontal-shear

values otherwise permitted.

In joists supported on a ribbon board and

spiked to the studding, the allowable stress in

compression perpendicular to the grain may be

increased 50 percent.

4- Posts

Wood posts when used as columns in basements or cellars shall bear on concerete bases

extending not less than 3 inches above the

finished floor. The base shall bear directly on

the post footing. When the floor is not of concrete or other solid material impervious to termites, concrete bases for wood posts shall be

not less than 6 inches above the finished floor.

" Tables of working stresses containing specific values consistent with

these general requirements will be found in par. 709-3 of the Appendix.

6. Splicing

Structural framing members shaU not be

spliced between bearing points unless approved

by the building official.

6. Exterior Walls

(a) Load-carrying capacity.—^Exterior walls

shall be designed to carry safely all loads as

specified in Section 702. (See Appendix, par. 709-6 (a).)

(b) Sheathing.—Exterior walls not having

diagonal wood sheathing shall have diagonal bracing at all corners. Such other measures shall be taken to secure rigidity as may be necessary.

Wood sheathing boards shall be not less than

6 inches in width and shall be nailed to each

stud, using not less than two eightpenny nails to each stud for boards up to 8 inches wide and

three nails for wider boards. Other forms of

sheathing shall be nailed as required by the

building official. (See Appendix, par. 709-1.)

Sheathing shall be nailed to top and bottom

plates and to sills. (See Appendix, par. 709-1.)

In frame construction of 2 or 2}^ stories where

the studs are not continuous from sill to roof

and diagonal sheathing is omitted, other

sheathing or connections shall be provided so designed as to supply adequate structural

continuity between first and second stories to

resist lateral pressures.

(c) Masonry veneer on Wood-Frame construction.—Masonry veneer applied to the walls of

frame construction shall rest directly upon the

masonry foundation of the structure and shall be not less than 3% inches in thickness.

Corrosion-resistant flashing shall be installed

when necessary to prevent moisture from penetrating behind the veneer. Masomy veneer shall be securely attached to the frame structure, at intervals of not more

than 16 inches vertically and 24 inches horizontally, with noncorrodible nails or ties. A waterproof covering shall be securely

attached to the framework of the structure back of the masonry veneer.

(d) Stucco on Wood-Frame construction.—Corrosion-resistant flashing or other expedients

13 For best results, a covering should be used that permits the passage

of moisture in the form of vapor from the inside to the outside.

[29]
that will prevent penetration of moisture behind the stucco shall be used wherever

necessary.

Where sheathing is omitted, approved corner and wall bracing shall be used. If a wall is back-plastered, the plaster shall be of sufficient

thickness to extend back between the studs a distance of not less than % inch. (See Appendix, par. 709-6 (d) .) Metal reinforcement, when used, shall be of

expanded metal fabric weighing not less than

1.8 pounds per square yard or of wire fabric

weighing not less than 20 pounds per 100 square

feet, and having openings not less than % inch nor more than 2 inches in greatest dimension.

Where sheathing is omitted, the weight of such

metal reinforcement or mesh shall be not less than 3.4 pounds per square yard.

Metal reinforcement for stucco of any type

shall be furred away from sheathing or building

paper at least % inch at all points by the use of approved furring nails or devices or by suitable

metal strips unless self-furring metal lath is used.

.The thickness of stucco when applied on

metal lath or similar reinforcement shall be at

least 1 inch and the metal reinforcement shall be covered on the exposed face at least % inch.

(e) Ribbon boards.—Ribbon boards used to support joists shall be not less than 1 by 4

inches, shall be cut into the studs, and securely

naUed with not less than two tenpenny naUs

to each stud. The ends of joists adjoining

studs shall be securely spiked to the studs.

Wood blocking shall be inserted at the ends of

joists not adjoining studs.

(J) Notching of studs.—In bearing walls or

partitions, no stud shall.be cut more than onethird its depth to receive piping and duct work

or for other purposes. If more depth is re- quired, the width of studs shall be increased

accordingly.

ig) Plates.—Plates in exterior walls used to support joists or rafters shall be double, with

each piece not less than 2 inches thick and the same width as the supporting studs.

(Ji) Framing over openings in bearing walls}^—

» These requirements are based entirely on structural considerations. Attention should also be given to possible shrinkage effects due to the depth of the member. Where excessive shrinkage is indicated, resort should be had to trussing or other methods. (See Appendix, par. 709-6

(b).)

Lintels and trusses in 2- by 4-inch bearing

stud waUs shall have heights and spans designed in accordance with good engineering

practice, provided that no lintel shall be less than the equivalent of two 2- by 4-inch members on edge.

(?') Jambs in bearing walls.—All window and

door openings in bearing walls shall have studs

doubled on jambs. Such studs may be sepa- rated when effectively blocked to act as a unit.

The inner stud may be cut to receive the lintel or header over the opening but shall extend in one piece from lintel or header to bearing.

7. Interior Partitions

(a) Load-carrying capacity.—WaUs shall be

designed to carry safely the full dead and live loads. (See Appendix, par. 709-6 (a).)

(6) Plates.—In 2- by 4-inch stud construction the bearing partitions shall be provided

at the top with double plates, each at least 2 inches thick and of the same width as the studs.

When the joists are placed directly above each

stud, a single top plate may be used, provided

that joints in the plate are properly spliced to form a continuous tie and the ends are tied to adjacent walls. If properly firestopped, studs

may run through the floor and rest on girders or on partition plates.

Partitions not resting upon girders or on

partition plates below shall have sole plates of dimensions not less than that of the studs.

Partitions unsupported by walls shall be

supported on girders or double joists or on

j sole plates if placed at an angle to the joists.

Nonbearing partitions of 2- by 4-inch stud , construction shall be provided with at least

\ one 2-inch plate on top and bottom of same

width as the studs or be otherwise properly

firestopped at floor lines. .

, (c) Framing over openings in bearing partitions.—Framing over openings in bearing par- ! titions shall conform to the requirements in

Section 709-6 (h) for framing over openings in

bearing walls.

8. Floors and Roofs

(a) Joists and girders. —When supported by

masonry, joists shall have ample bearing but

not less than 3 inches.

[30]
Each tier of floor joists entering masonrywalls shall be securely anchored thereto to

resist safely a lateral force equal to the assumed

wind pressure. Such anchorage may consist

of T-shaped steel anchors attached to every

fourth joist but not more than 6 feet apart.

The ends of joists shall be beveled and anchors shall be so attached that the joists will be released from the walls in case of fire. Joists running parallel to enclosing walls

shall be anchored to the walls to resist safely a lateral force equal to the assimied wind pressure. Anchors shall be spaced not more than

8 feet apart and shall extend back and engage

at least three joists.

When enclosing walls are of wood, each joist,

beam, and girder in the wall shall be securely

spiked or anchored to the wall construction,

so as to stay in place and to resist safely all

lifts and lateral pressures required to be as- siuned by this Code.

Girders shall be fastened to each other where

they intersect or abut, so as to resist safely a lateral force equal to the assumed wind

pressure. Floor joists framing into the side of wood

girders shall be supported on metal joist hangers

or on a bearing strip or ledger board on the side

of the girders. Such strips or boards shall measure at least 2 by 3 inches. The notch in the end of the joist shall be not more than onefourth of the joist depth, and the shearing

stress shall not exceed the allowable stress when

calculated in accordance with good engineering

practice.

The ends of joists, whether resting upon

girders or bearing partitions or abutted against

the girders, shall be securely tied to the girders

or to each other, so as to resist safely an outward

thrust on the walls equal to the assumed wind

pressure or the spreading action of the roof,

whichever is the greater.

AH joints of solid and built-up wood girders

shall be made over column or pier supports.

Joists supporting nonbearing partitions which

are parallel to the joists shall be doubled.

When nonbearing partitions weighing more

than 120 pounds per linear foot are not parallel

to joists, the joist size shall be increased over

that required for normal loading or the joist

spacing shall be decreased. Where the partition is located at or within 1 foot of the center

of the span, the joist size shall be that required

for a span 2 feet greater than the actual span.

For other positions of the partition, the size of

the joist may be uniformly decreased to the

size required for ordinary loading when the

partition is over the joist supports.

Joists shall not be notched within the middle

one-half of the span. The top and bottom

edges of joists may be notched in the outer

one-quarter of the length, provided the notch

does not exceed one-sixth of the joist depth.

(b) Headers and trimmers.—Design of headers

and trimmers shall conform to good engineering

practice.

AU headers and trimmers shall be doubled

except headers receiving not more than three

tail beams and trimmers receiving a header

with only one tail beam not over one-sixth of

the joist span from the support. (See Appendix, par. 709-8 (b).)

(c) Support of rafters.—Rafters shall be

vertically supported near the ridge when the

slope is less than 4 inches per foot. Rafters,

regardless of slope, shall be thus supported

unless they are held from spreading. If the

spread of the rafters is held by ties not at the

plate line, the size of rafters shall be increased

to take care of the additional bending moments

induced by the ties when the roof is loaded

with the maximum vertical load. (See Appendix, par. 709-8 (c).) Wood rafters shaU be so spiked, or otherwise fastened to the plate or other members

as to resist safely all thrusts under fuU load

and the upward lift, but not less than the

equivalent of two sixteenpenny nails to each

rafter end shall be used. (See Appendix, par. 709-1.)

If the rafters rest upon partitions as in a

one-and-one-half-story house, these partitions

shall be considered as load bearing and the

floor joists shall be increased in size to take

care of that part of the roof load carried by

the partitions.

(d) Bridging.—Floor and flat-roof joists and

beams shall be securely bridged at intervals not

exceeding 8 feet. (See Appendix, par. 709-8

(d).)

466009° —42 5 [31]
9. Plank-and-Beam Construction

(a) Design.—Plank-and-beam construction

shall conform to good engineering practice.

(See Appendix, par. 709-9.)

(6) Beams.—The spaciag of beams, center

to center, shall in no case exceed 52 times the

actual thickness of the plank. Beams shall be

not less than 3 inches, nominal dimension,

thick nor have a depth-width ratio more than

4 based on actual dimensions. When beams

axe buUt of two or more laminations, the

depth-width ratio of a single lamination shaU

not exceed 6 based on actual dimensions.

Floor beams shall not be notched unless

additional section is provided. Beams shall not bear over doors or windows without special

provision for their support.

(c) Plank.—Plank shall be 2 inches or more

in thickness and 6 inches or more in vpidth,

nominal dimensions, and shaU be tongue-andgroove or splined.

Well-seasoned plank, with a moisture content close to that which it would reach in

service, shall be used. The plank shaU be laid at right angles to the supporting beams and

shall be both blind- and surface-naUed. Planks

which are continuous over two spans, or singlespan planks which are distributed so that they

do not occur in adjacent positions, may be

used on spans not exceeding 52 times the actual

thickness of the plank. Wliere it is necessary

to have single-span planks in adjacent positions,

the span shaU not exceed 45 times the actual

thickness of the plank.

id) Exterior-wall framing.—Studs shall not

be spaced more than 24 inches on centers. Floor, roof, and ceiling beams shall be supported at the exterior walls upon posts which

are adequate to support the load and whose

dimensions are not less than 4- by 4-iach nominal size.

(e) Interior columns.—Where beams abut

over a column, a column dimension of not less than 8 inches parallel to the direction of the

beams shall be used to provide suitable bearing

for the beams. Basement columns shall have

a cross section of at least 6 by 6 inches; those

" Plank-and-beam structuraJ floor or roof system consists of plank

subfloor or roof decking with supporting beams spaced up to 7 feet apart, instead of the usual boards for subfloor or roof decking with joists or rafters spaced the customary 12 to 24 inches.

in other stories shall be at least 4 by 4 inches,

all dimensions being nominal.

(J) Fastenings.—All structural members shall be adequately nailed to each other at their

junction to provide a well-integrated structure. Girders shall be fastened to each other where

they intersect or abut, so as to resist safely a

lateral force equal to the assumed wind pressure.

10. Wood Houses With Plywood Coverings

(a) Material.—The term "plywood" as used

in this Code shall mean a built-up board or

piece of wood made of three or more layers of veneer joined with glue and so laid that the

grain of adjacent plies is at right angles. An

odd number of plies shall be used.

Plywood to be exposed to the weather or to severe conditions of service shall meet the

requirements established for "Exterior Class" in

Commercial Standard CS45^0 for Douglas Fir

Plywood. (See Appendix, par. 709-10 (a).) Plywood for interior use above grade and not

subjected to severe conditions of service shall meet the requirements established for the

"Moisture Kesistant Class" in Commercial

Standard CS45-40 for Douglas Fir Plywood.

(See Appendix par. 709-10 (a).)

(6) Gluing plywood toJraming members.—Glue

at least equal to casein or cold-press resin glue

shall be used for gluing plywood to framing

members of walls and ceilings used under nor- i mal conditions of service. The casein glue

shaU meet the requirements of Navy Department Specifications 52G8b (July 1, 1932) for water-resistant casein glue. Cold-setting resin

glue shall meet the requirements of Navy Aero- ' nautical Specification Glue; Cold-Setting Resin

G-29 (4 April 1941). (See Appendix, par. 709-10 (b).)

'

Joints shall be of such quality that when

tested to destruction in the dry condition, at

least 50 percent of the failure shall be in the

wood.

Similar glue joints may be used for floor units '

if adequate ventilation beneath the house is

' provided. (See sec. 709-11 (d).)

(c) Design of flat panel with stressed cover- ings.—Design of flat panel with stressed coverings shall conform to good engineering practice.

(See Appendix, par. 709-10 (c).)

[32]
(d) Fastenings.—AR structioral members shall be so comiected at their junction as to provide

a well-integrated structure. The fastenings of ponel coverings to longitudinal members by any means less rigid than

gluing (such as nailing) shall not be considered

as providing a stressed covering.

11. Termites and Decay

(a) Site of building.—Adequate drainage shall be provided at the building site.

(b) Removal of debris.—All wood debris shall be removed from the building site before construction is begun. No boards, stakes, or

scraps of lumber shall be buried or left about the

building.

(c) Foundations.—All foundations shall be

made impervious to termites. If unit masonry

is used it shall be capped with 4 inches of reinforced concrete or equivalent.^®

{d) Foundation wall wenis.—Adequate cross ventilation shall be provided beneath all wood

construction over the ground so that no dead-air

pockets exist. For each area enclosed by exterior, fire, common-property-line, or party walls, the minimum

net area of vent openings in the exterior walls

shall be equal to one-half of 1 percent of the

enclosed area plus one-half of 1 square foot for each 25 lineal feet of wall surrounding the area. When the building site is relatively wet at frequent periods, the area of openings thus obtained shall be doubled.

(e) Porches.—Porches, steps, and terraces

shall be insulated from the foundation and woodwork so as to prevent termites and moisture

from gaining access to the building from the fill or space beneath the entrance platform. (See

Appendix, par. 709-11.)

(/) Selection of lumber.^''—No lumber showing

evidence of decay shall be used.

(g) Closeness to ground.—Except as permitted

in Section 704^ (a), no wood shall be placed

in contact with the soU. Clearance under

buildings without basements shall be a minimum

" Requirements concerning termites are Intended only tor those areas where it has been established that termite infestation exists. (See Appendix, par. 709-11.) " Precautions should be taken to guard against excessive moisture

.content caused by conditions during delivery and installation.

of 18 inches below the bottom of all wood substructures, to allow crawl space for making

inspections. Access doors or openings shall be

provided.

All wood used in basements, such as stair

carriages, door frames, partitions, or posts,

shall rest on poured-concrete plinths, pedestals, or curbs that extend above the general floor

level.

(h) Girders in masonry or reinforced-concrete

walls.—Air spaces of inch or more shall be

provided around the ends of girders located

below or near the grade line and which rest on masonry or reinforced concrete from which

moisture may be absorbed, unless the girders are treated with an approved pressiu'e preservative treatment or are made of all heartwood of one of the more decay-resistant species. (See

Appendix, par. 709-11.)

(i) Floor sleepers.—Floor sleepers, furring

strips, or other wood embedded in or laid on masonry or concrete that is in direct contact

with the ground shaU be treated with an

approved pressure preservative treatment.

Pieces shall be completely framed before treat- ment whenever possible ; but when cutting after treatment is unavoidable, the cut surfaces shall be given two brush coats of a suitable preservative. (See sec. 704-4 (a) .) (j) Protection of material.—Every other material into the composition of which cellulose enters and which forms a part of a building shall be protected in a manner similar to that required

for wood.

(k) Expansion joints.—Expansion joints in

floors and space around pipes penetrating

floors and walls shaU be sealed with coal-tar

pitch, coal-tar plastic cement, or crimped metal

connectors.

(/) Water pipes.—Water pipes shaU be sus- pended from the joists in basements to prevent

the absorption of condensation water by the

wood.

(m) Flashing over doors and windows.—Adequate flashings shall be used over doors and

windows to provide ready drainage of water.

(n) Moisture in walls. —A vapor-resistant

barrier shall be used at or near the inner face

of the exterior walls to prevent the accumvdation of moisture in the walls.

[33]
CHAPTER VIII. FIRE PROTECTION

Section 800. Geneeal

When construction is required to have a

definite fire resistance, this shall be determined

under the procedure set forth in the Standard

Specifications for Fire Tests of Building Construction and Materials, ASTM Designation

C 19-41 of the American Society for Testing

Materials. (See Appendix, par. 800.)

The provisions of this chapter are minimum

requirements for fire-protection piirposes and

shall not be deemed to modify any other requirements of this Code, nor shall they be construed

to modify any zoning requirements that may

apply.

Section 801. Fiee Sepaeation

1. Between Dwellings

If dwellings are not attached or do not adjoin, a clear space not less than 10 feet wide shall be

left between them and a clear space not less than 5 feet wide shall be left between dwellings

and common property lines. (See ch. III.)

2. Between Dwelling Units

Walls, floors, and other construction separating dwelling units shall have a fire resistance

of at least % hour. Such walls or partitions

shall extend from the finished grade or from

floor construction having a fire resistance of not

less than % hour when over a common basement

or cellar. When the attic space is or can be

used for storage, they shall extend up to the

under side of the roof sheathing; provided that

when attic space cannot be used for storage

and there is an incombustible finish on the

ceiling of the top story, the walls or partitions

may terminate at the ceiling of such story.

(See ch. III; sec. 402-2; and Appendix, par.

801.)

3. Fire Walls

Fire walls shall be ground supported, and

self-supporting in the event of collapse of adjoining construction on one side. They shall extend to the inner face of waU and roof sheathing. In the case of roofs of masonry or reinforced concrete, fire waUs shall be buUt up

tightly to the under side of the roof.

4. Chimneys

No combustible beams, joists, or rafters

shall be placed within 2 inches of the outside

face of chimneys or of masonry enclosing a flue,

provided that this distance may be reduced to inch when the members are faced to their

full depth with asbestos insulating board or other approved insulating material not less than Yi inch thick. No combustible stiidding,

lathing, fuiTing, or plugging shall be placed

against any chimney or in the joints thereof. Such combustible construction shall either be

set away from the chimney or the plastering

shall be directly on the masonry or on metal

lath and furring or on other incombustible

lathing and furring material. Combustible fur- ring strips placed around chunneys to support

base or other trim shall be insulated from the

masonry by asbestos paper at least Y, inch

thick, and metal wall plugs or approved incombustible naU-holding devices attached to the

wall surface shall be iised for nailing.

5. Hazardous Spaces

Except in single- and two-family dwellings,

boiler rooms, incinerator rooms, storage rooms

for inflammable materials, and coal bins shall be enclosed by incombustible construction having a fire resistance of at least % hour. Openings into such enclosures, except coal bins, shall be protected by approved self-closing fire doors.

6. Garages

When a garage for not more than two auto- mobiles is located within a single- or two-family

dwelling, the waUs, partitions, and ceiling shaU

be protected on the garage side with a fire- resistant construction at least equal to an in- combustible facing not less than inch thick or with such a facing not less than % inch thick

backed with tongue-and-groove boards not less than 1 inch in nominal thickness.

When a garage for more than two and not more than five automobiles is located within a dweUing, the floor construction above the

garage and the walls and partitions enclosing it shall have a fire resistance of at least % hour.

[34]
When a garage for more than five automobiles

is located within a dwelling, the floor construction above the garage and the walls and partitions enclosing it shall be fireproof.

When a garage is attached to a dwelling, the

ceiling construction over the garage and the

walls separating it from the dwelling shall be

of construction conforming to that given above,

according to the number of automobiles accom-

; modated.

When a garage accommodates up to five automobiles, openings from a dwelling into the

garage shall be restricted to a single doorway

provided with a door covered with metal on the

garage side or a flush type wood door not less than 1% inches in nominal thickness. In the

case of garages accommodating a larger number

of automobiles, such openings shall be provided

i with approved self-closing fire doors. No glass

shall be permitted in any door between a dwell-

' ing and a garage. Every door sill shall be

raised at least 7 K inches above the garage floor

' level.

' Garage floors shall be of incombustible

material.

Heating devices for garages shall be instafled

, in approved separate heating rooms or shall be

I of an approved type installed approximately at

ij the eave level or near the ceiling.

Section 802. Firestopping

1. General

Firestopping shall be supplied at the locations specified in this section and shaU be so arranged as to cut off all concealed draft openings and form an effectual fire barrier between

stories and between the upper story and the

roof space. (See Appendix, par. 802-1.)

2. Exterior Walls

(a) Wood construction.—Exterior walls of

wood construction shall be properly firestopped

at each floor level and at the level where the

roof rafters connect with the wall plate.

(6) Furred spaces.—For all masonry waUs

that are furred or studded off, the space created

by the furring or studding shall be properly

firestopped once in each story. Spaces around

chimneys shall be firestopped with incombustible material.

3. Partitions

Where stud partitions rest directly over each

other and the studs run down between the floor beams and rest on the top plate of the partition

below, the spaces between the studding shall be

properly firestopped.

4. Stairs

The space between stair carriages shall be

firestopped by a header beam at top and bottom. Where a stair run is not aU in one room

or where a closet is located beneath the stairs,

the stair carriages shall have an intermediate

firestop, so located as to cut oft" communication between portions of the stairs in different rooms, or between the closet and the room in

which it is placed. Such stops shall be made of

plank or other suitable material.

If a fhght of stairs leading to the second story

is over a flight of stairs leading to the basement

or cellar, the stair construction to the second

story shall have a fire resistance of at least 1 hour, provided that this shall not apply to stairways within dweUtng units.

5. Pipes or Ducts

Where any pipe or duct passes through a

floor, the space between the pipe or duct and

the floor construction shaU be firestopped.

Where the tnstaUation of pipes, ducts, or conduits in waUs, floors, or partitions requires

the removal of any firestopping, the spaces

around the pipes, ducts, or conduits at such

points where firestopping was removed shaU

be tightly filled with asbestos, mineral wool,

or other incombustible insulating material.

6. Sliding Doors

When sliding doors are pocketed in partitions,

such pockets shall be completely firestopped at the top, bottom, and ends.

7. Exterior Cornices

Exterior cornices built of wood or having

wood frames on rows of buildings shall be either

fully firestopped between each building or completely separated.

[35]
8. Inspection

No firestopping shall be concealed from view

until opportunity has been given the building

official to inspect the same.

Section 803. Shafts

1. Enclosure Required,

Shafts passing through space occupied by

more than one dwelling imit shall be enclosed

with construction having a fixe resistance of at

least % hour.

Shafts passing through more than one story of

space occupied by one dwelling unit shall be

lined with sheet metal or other approved in- combustible material.

The bottoms of shafts not extending to the

basement or cellar floor and the tops of shafts

not extending through the roof shall be enclosed as required above.

2. Openings

Openings in shafts shall be restricted to those

necessary for the purpose of the shaftway.

Such openings shall be protected with approved

fire doors or other approved protective devices

in the case of shafts required to have a definite

fire resistance and by doors or other devices

lined with sheet metal or other approved in- combustible material in the case of shafts re- quired to be lined with metal or incombustible

material.

S. Connections

The connections of shafts to adjoining construction having a lower fire resistance shall be

such that the fire resistance of the enclosure will

be maintained.

Section 804. Roof Coveeings

Roof coverings shall conform to the following

classifications, whose use is governed by the

requirements of this Code for types of construction:^*

Class 1 roofing materials shall be effective

against severe fire exposures, shall not carry or communicate fire, shall afford a relatively high

degree of protection against fire to any combustible roof deck on which they may be placed,

" For specific materials that will meet these requirements, see Appendix, par. 804.

shall not slip from position, shall possess no

flying-brand hazard, and shall not require fre- quent repairs to maintain their fire-protective

properties.

Class 2 roofing materials shall be effective

against moderate fire exposures, and shall not

be readily flammable or carry or communicate

fire. They shall afford a moderate degree of protection to the roof deck, shall not slip from

position, shall possess no flying-brand hazard,

and shall require only infrequent repairs in order to maintain the above properties.

Class 8 roof coverings shaU not be readily

flammable or carry or communicate fire under

light fire exposures, shall afford some degree of protection to the roof deck, shall not slip from

position nor possess any flying-brand hazards,

and shall maintain these properties with only

occasional repairs.

Class 4 roof coverings present less resistance

to ignition from sources such as flying brands

than the Class 3 coverings and give at least a

slight degree of protection to the roof deck. In burning they will give off flying brands. Their

susceptibility to ignition from brands on the

roof will increase with time. As applied by ac- cepted methods, they will not slip from position.

Class 5 comprises wood shingles that on ac- count of thickness, length, treatment, coatings,

underlay, or supporting sheathing are not in- cluded in Class 3 or 4. It does not include very

readily ignitable and hazardous roofing materials such as light asphalt or tar-impregnated

paper and straw thatch.

CHAPTER IX. CHIMNEYS AND HEATING APPLIANCES

Section 900. General

Chimneys and heating appliances shall be

constructed and installed in accordance with

good practice, provided that the specific re- quirements in this chapter shall be observed.

(See Appendix, par. 900.)

Section 901. Construction of Chimneys

1. Materials

Chimneys shall be of approved masonry or reinforced concrete or of other approved

materials.

[36]
2. Foundations

Masonry or reinforced-concrete chimneys

shall not rest upon or be carried, by wood

floors, beams, or brackets, nor be hung or supported by metal stirrups from wood construction, but shall be built upon concrete or masonry foundations or reinforced-concrete

slabs properly proportioned to carry the load

without danger of settlement or cracking. The

footings shall be carried below the frost level.

S. Bonding

Masonry or reinforced-concrete walls of

buildings may form parts of chimneys when the

chimney walls are securely bonded into the

walls of the building and when the flue is lined with flue lining the same as an independent chimney.

4. Corbeling of Chimneys

Corbeled chimneys shall not be supported

by hollow walls, cavity walls, or walls of hollow

units. SoHd walls supporting corbeled chimneys shall be not less than 12 inches thick,

and corbeling shall not project more than 1 inch per course and not more than 6 inches

in any case. The total offset, overhang, or corbel of an

independent chimney shall not exceed % the

width of the chimney in the direction of the

offset.

5. Height

Chimneys shall be built at least 2 feet above

flat roofs, provided that the tops of chimneys

shall not be below the tops of adjacent parapet

walls. In the case of sloping roofs, chimneys

shall be not less than 1 foot above the ridge

of the roof that the chimney penetrates and

not less than 1 foot above the highest ridge

within 10 feet of the chimney. Unless provided with a stone, terra-cotta, concrete, castiron, or other special cap or top, the chimney

lining shall project not less than 2 inches. No

chimney top shall decrease the required flue area.

6. Concrete Chimneys

Concrete for chimneys cast in place shall flow readily, be well rodded, and shall be reinforced vertically and horizontally. The walls

shall be at least 3% inches thick and shall be

lined throughout with fire-clay flue lining.

7. Hollow Masonry Units^^

Hollow masonry units shall not be used for

the walls of an independent chunney, but may

be used for chimneys built in connection with

exterior walls of buildings built of hollow units,

in which case the chimney walls shall be at least 8 inches thick. The outer 8 inches of a building

waU may serve as the outside wall of the

chimney, but the remaining chimney waUs

shall be constructed of two layers of 4-inch

hollow units set with broken vertical joints, or they may be built of 4 inches of solid masonry.

In either case, the outside wall of the chimney

shall be securely bonded into the walls of the

building. No chimney shaU be corbeled from a

wall built of hollow imits.

8. Solid Concrete Block

Solid concrete block used in chimney construction shall be at least 3% inches thick, and blocks

enclosing more than one flue shall have suitable

reinforcement completely encircling the blocks

and well embedded in them.

9. Stone

The walls of chimneys built of sawed or dressed stone in courses, properly bonded at corners and tied with metal anchors, shall be

at least 3^^ inches thick. Chimney walls of

other stone shall be at least 8 inches thick.

10. Flashing

Connections between chimneys and roofs

shall be made with cap and base flashing of

sheet metal or other approved material, ar- ranged to allow for any lateral or vertical move- ment between chimney and roof.

11. Change of Interior Dimensions

No change in the interior dimensions of

chimneys shall be made within a distance of 6

inches above or below the rafters or roof joists.

" Tests now in progress may disclose the advisability of relaxing these requirements.

[37]
12. Special Types oj Chimneys

Chimneys of construction other than covered

in the foregoing requirements shall be permitted

only when approved by the building official and installed in accordance with regulations

issued by him. (See Appendix, par. 901-12.)

Section 902. Flues

1. Flue Lining

Chimneys built of brick, stone, or other

masonry units shall be lined throughout with

fire-clay flue lining; provided that in chimneys

having solid brick walls 8 inches or more thick,

the flue lining may be omitted. Flue linings

shall be at least % inch thick, and shall be

suitable for the purpose and adapted to withstand high temperatures and the resultant gases

from burning fuel. The flue sections shall be

set in Type A or Type B mortar. The joints

shall be smooth on the inside.

2. Separation

When two or more flues are contained in the same chimney, withes of brick or mortar not

less than 3% inches thick shall be provided at

intervals not exceeding 30 inches horizontally,

but not more than two flues without such

separation. Where the flue linings are not

separated by withes, the joints shall be staggered and the vertical distance between joints

in adjoining flue linings shall be not less than 7

inches.

S. Construction

The masonry shaU be built around each sec- tion of lining as it is placed, and all spaces

between masonry and linings shall be filled with

mortar. Linings shall start at least 8 inches

below the center line of smoke-pipe intakes or, m the case of fireplaces, from the apex of the

smoke chamber and shall be continuous the

entire height of the flue. No smoke-pipe in- take shall be cut into a flue lining already set in

place. Flues shall be built as nearly vertical as possible, but in no case at an angle greater

than 45 degrees from the vertical. Where

flues change direction, the abutting linings at the angle joints shall be cut to fit closely, and

at no point shall the cross-sectional area be

reduced.

4.. Area

The inside effective area of flue linings shall be not less than the area of the smoke outlets on the appliances to which the flue is connected,

but not less than K2 the opening for fireplaces.

The least dimension of any rectangular flue shall be not less than K of the greatest di- mension.

For flues serving several gas appliances, the

flue area shall be at least equal to the aggregate

areas of the appliance outlets. Single vent flues for storage water heaters,

stoves, ranges, and other domestic gas appli- ances having relatively small gas consumption

shall have a flue diameter of at least 3 inches,

provided, however, that this shall not apply

to gas plates and portable gas heating appli- ances. Such flues, unless enclosed in solid

masonry walls, shall be of incombustible material of approved design and thickness, and

shall vent through and above the roof. The diameter of a vent flue serving a gasfired instantaneous or continuous-flow water

heater shall be not smaller than the diameter

of the outlet on the appliance to which it is connected.

5. Gleaning

Flues shall be thoroughly cleaned and left smooth on the inside.

Section 903. Fireplaces

1 . Use oi Firebrick

The walls of fireplaces shall be not less than

8 inches thick, provided that if built of stone

or hollow units they shall be not less than 12 inches thick. The faces of such minimumthickness walls exposed to fire shall be lined

with firebrick, soapstone, cast iron, or other

suitable fire-resistive material. When lined

with at least 4 inches of firebrick, such lining

may be included in the required minimum

thickness. When the firebrick lining is less than 4 inches thick, such lining shall not be

included in the required thickness.

2. Incombustible Hearths

Fireplaces, except when designed and used

for approved gas appliances only, shall have

hearths of brick, stone, tile, or other approved

[38]
incombustible material supported on masonry

or reinforced concrete. Such hearths shall extend at least 16 inches outside the chimney

breast and not less than 8 inches each side of

the fireplace opening along the chimney breast.

The arches shall be of brick, stone, hollow tile, or other approved masonry at least 4 inches

thick. A flat stone or a reinforced-concrcte

slab may be used to carry the hearth instead of an arch, if it is properly supported and a suitable

fill is provided between it and the hearth.

Hearths shall be of brick, stone, tUe, or concrete, as may be specified. The combined

thickness of the hearth and supporting arch

or slab shall be not less than 6 inches at any

point.

3. Fire Prevention

(a) Removal of wood centering.—Wood center- ing used in the construction of any part of the

supporting arch of a fireplace, which is below

the hearth and inside the chimney breast, shall be removed when the construction of the arch

is completed and before plastering on the

underside.

(6) Clearances from combustible construction.—No combustible construction shall be

placed within 4 inches of the back wall of any

fireplace. Combustible or unprotected header

beams supporting trimmer arches at fireplaces

shall be not less than 20 inches from the face

of the chimney breast.

No combustible mantel or other combustible

construction or finish shall be placed within

8 inches of either side or of the top of sin.y fire- place opening, provided that no combustible

mantel shelf shall be less than 12 inches above

such openmg.

Section 904. Smoke Pipes

1. Connection With Flue

(a) Connection required.—Every smoke pipe

shall connect with a smoke flue by means of a

tight joint.

(b) Number limited.—Not more than one smoke pipe shall be connected to a flue. A vent

from a gas-burning appliance not exceeding 13

square inches may connect into the same flue as a smoke pipe provided the connection is above the smoke pipe.

(c) Thimbles.—Thimbles shall be built in at the time the chimney is buUt. Smolce pipes

shall enter chimneys through a fire-clay or metal thimble or flue ring of masonry. Neither

the intake pipe nor the thimble shall project

into the flue.

2. Passage Through Combustible Construction

(a) Ceilings, floors, roofs.—No smoke pipe

shall pass through a ceiling, floor, or roof construction of combustible material.

(6) Partitions.—Smoke pipes shall not pass

through combustible partitions, unless protected by double metal ventilated thimbles

8 inches larger m diameter than the pipe or 4 inches larger in. diameter than the pipe, with

the space between the pipe and the thimble

filled solidly with approved incombustible in- sulating material, or unless protected by a concentric sleeve of diameter 2 inches larger than

the pipe, with the space between fflled solidly

with incombustible insulating material and the

outside surface of the sleeve distant at least 2 inches from combustible material.

S. Clearances From Combustible Construction ^° The clear distance in aU directions between

a smoke pipe and combustible construction,

including plaster on a combustible base, shah

be not less than 12 inches; provided that this

clearance may be reduced one-half when such

construction is protected by cement-asbestos

board or asbestos millboard not less than %

inch thick or equivalent approved covering

extending the full length of the smoke pipe and

not less than 12 inches beyond it on both sides, or where plaster is on metal or wii-e lath.

Section 905. Mounting of Heat Appliances

1. General

Except as hereinafter otherwise provided,

heat appliances shall be momited on masonry

bases not less than 3 inches thick supported on

the ground, or they shall be mounted on floors of fireproof construction with incombustible

floormg or surface finish, or on trimmer arches

supporting hearths as requned in this Code for

fii'eplaces, in all cases extending not less than 12

2» These clearances may be decreased when it has been established by

test that lesser distances are safe for a particular installation.

466009°—42 6 [39]
inches beyond such appHances on all sides or to the partitions of the room in which the heater

is located.

Hearths

Stoves or ranges burning solid fuel, the lower

surface of which is a portion of the fire box,

shall be set on hearths supported by masonry

trimmer arches extending not less than 6 inches on all sides beyond such appliances; provided

that when such appliances have legs giving an

open air space of not less than 5 inches below

the bottom of the appliance, they may be set on sheet metal underlaid with not less than %

inch of asbestos or other equivalent approved

incombustible material; and, provided further,

that where such appliances have ash boxes

under the entire fire box and are set on legs

giving an open air space of not less than 5

inches below the bottom of the appliance, they

may be set on sheet metal.

S. Clearances Jor Stoves and Ranges^^

No stove or range shall be placed within 24

inches from combustible construction nor within

18 inches of combustible supports or combustible base of plastered construction; provided

that when such construction is protected by a

shield of galvanized or bright sheet metal or other equivalent approved incombustible material extending from the floor to 1 foot above

and 1 foot beyond the sides of such appli- ances, these distances may be reduced one-half.

4- Clearances for Gas Ranges

Domestic gas ranges shall have a distance

between the burners and a combustible floor of not less than 12 inches unless such floors are protected with asbestos board under sheet

metal or other equivalent approved incombustible material. The oven back or side of the

cooking top shall be not less than 6 inches from

combustible material unless such material is protected by approved incombustible material

as in the case of burners.

21 These clearances may be decreased when it has been established by

test that lesser distances are safe for a particular stove or range and such

clearances are recommended by the manufacturer.

5. Bases Jor Heating Furnaces

Unless otherwise approved by the building j official, hot-air, hot-water, and steam heating \ furnaces installed on wood-joisted floors or on i other combustible construction shaU have i protective bases of sheet metal or asbestoscement board. In addition to and above this

base, there shall be a hollow masonry base ' arranged for free air circulation through it for i all coal-fired equipment and for aU other equip- t ment not protected by a wet base or which ; does not have a combustion chamber at least ! 12 inches above the floor.

6. Clearances for Heating Furnaces^^ j No hot-air, hot-water, or steam heating j furnace shall be located nearer than 24 inches

j in any direction to woodwork or other com- i bustible material or construction, including

plaster on combustible base. In the case of furnaces which are enclosed in jackets providing an air space or which are insulated in an ; approved manner, this distance may be reduced

to 18 inches; provided that when combustible

material is protected with %-inch gypsum

board under }^-inch asbestos board, or with

%-inch Portland cement plaster on metal

lath, this distance may be further reduced to not less than 6 inches.

Section 906. Ducts !

1. Material

Warm-air ducts, fittings, and connections in

warm-air heating systems shall be made of

bright tin, galvanized iron, or other approved

incombustible material.

2. Protection

(a) Clearances from combustible construction.—

The clear distance between exposed warm-air

ducts leading from the furnace to vertical or waU stacks and combustible construction shaU

be not less than 1 inch unless such construction

is covered with asbestos paper weighing not

less than 12 pounds per 100 square feet and

the paper covered with galvanized or bright

23 These clearances may be decreased when it has been established by

test that lesser distances are safe for a particular type of heater and such

clearances are recommended by the manufacturer.

[40]
sheet metal, or unless equivalent protection is provided.

(6) Clearances within floors and partitions.—

If the bonnet temperature of a warm-air heating

system exceeds 200° Fahrenheit, no warm-air

duct shall enter a floor, partition, or other

construction of combustible material unless it

is at least 6 feet distant in a horizontal direction from the furnace or imless it is covered

with asbestos paper or millboard at least Yt, inch thick or equivalent approved protection.

A clearance of not less than inch shall be maintained between combustible construction and warm-air heating stacks, floor or waU

ducts, and their inlets and outlets, and they

shall be covered with not less than one thick- ness of asbestos paper weighing not less than

12 pounds per 100 square feet, or equivalent

approved protection.

3. Cold-Air Buds

The cold-air ducts of heating systems within

6 feet of their connection with the furnace shall be of metal or approved incombustible material. Section 907. Registees

1. Setting

If the bonnet temperature of a warm-air

heating system exceeds 200° Fahrenheit, registers used in heating systems, placed in woodwork or in combustible floors, shall be sur- rounded with a border of incombustible material not less than 2 inches wide, securely set

in place, or shall be instaUed in some other

approved manner.

2. Register Boxes

If the bonnet temperature exceeds 200°

Fahrenheit, floor registers shall be provided

with double register boxes of tin or galvanized

iron or other approved incombustible material,

with an air space of not less than Yu inch

between inner and outer boxes; or, where single

boxes are used, they shaU be insulated from

the wood or other combustible material by

asbestos paper weighing not less than 12

poimds per 100 square feet and a clear space

of not less than inch shaU be left from

combustible material.

3. One-Pipe Furnaces and Floor Furnaces

When a register box is placed in a combustible

floor dii'ectly over a one-pipe furnace or floor furnace, the register box shall be constructed

double with a -Rented an- space of not less than

4 inches between, except where the warm-air

passage is surrounded by a cold-air passage.

Combustible material enclosmg register boxes

of waU-register type furnaces shall be insulated

from the register box with an incombustible

material having a maximum coefficient of heat

transmission of 1.0 Btu per square foot per

hom per degree of temperatine difference for

the thickness used.

With the exception of waU-register types of

furnaces, floor fm^naces shaU not be placed

closer than 6 inches to the nearest waU. Wallregister types shall not be placed closer than 6

inches to a corner. Furnaces shaU be so placed that a door,

drape, or similar object cannot be directly over

or less than 12 inches in front of the register of

the fmenace.

Jf.. Fixed Registers

If the bonnet temperature of a warm-air

heating system exceeds 200° Fahi'enheit, one

register without valve or movable louvers shaU

be provided in the system.

Section 908. Mechanical Cieculation WaemAiE Systems

1. General

Except as may be otherwise provided in law,

in this section, or in duly pi'omulgated regulations, the Standards of the National Board of

Fire Underwriters for the InstaUation of Air Conditioning, Warm Air Heating, Air Coohng and

Ventilating Systems or the recommendations

of the National Wann Air Heating and Air

Conditioning Association shall be deemed to be

generally accepted good practice in the design

and installation of mechanical cu'culation warmau' systems. (See Appendix, par. 908.)

2. Recirculation

The installation of equipment providing the

recirculation of an- from one dwelling imit to another is forbidden.

[41]
3. Return Ducts

No return duct of a mechanical circulation

warm-air system shall be permitted from a

kitchen, bathroom, or garage.

Section 909. Steam and Hot-Watek Pipes

1. Clearances From. Combustible Construction

Where steam or hot-water pipes pass through

combustible floors or partitions, or other combustible construction, there shall be on all sides

of the pipe an open space which shall be enclosed at the ends with incombustible material.

2. Pipe Coverings

Coverings or insulation used on steam or hot-water pipes shall be of incombustible

material.

Section 910. Appliances

1. Gas Appliances

(a) General.—Except as may be otherwise

provided in law, in this section, or in duly

promiilgated regulations, the Approval Requirements for Central Heating Gas Appli- ances and the Requirements and Recommended Practice for House Piping and Appli- ance Installation of the American Gas

Association shall be deemed to be generally

accepted good practice with respect to such

appliances. (See Appendix, par. 910.)

(b) Gas logs.—No gas log, gas grate, or similar

heating appliance shall hereafter be installed

except in a fireplace constructed as prescribed

by this Code and connected with a smoke flue or an outlet pipe as hereinafter provided.

(c) Gas-fired furnaces.—Gas-fired steam or hot-water furnaces shall be instaUed as pre- scribed in this Code for heat appliances and

shall be connected with a smoke flue conforming to this Code.

(d) Water heaters.—Water heaters shall be

connected to smoke flues or outlet pipes as hereinafter provided.

(e) Venting.-—Outlet pipes for venting gas

appliances shall be standard cast-iron soil pipe, terra-cotta pipe, or other approved incombustible material, so connected as to prevent

leakage at the joints.

Such outlet pipes shall have cross-sectional areas of not less than the aggregate areas of the

vent outlets of the appliances connected to them.

Such outlet pipes shall be connected to chimnej^s or be carried to and through the roof or through an exterior wall to the outer air. When not connected to chimneys, they shall be

surmounted by a suitable cap. Unless insulated with not less than one

thickness of asbestos paper weighing not less than 12 pounds per 100 square feet, or with

equivalent protection, such outlet pipes shall be separated from woodwork or other combustible material by a clearance on all sides of not less than 1 inch.

(/) Liquefied petroleum gases.—Except as may be otherwise provided in law, in this section, or in duly promulgated regulations, the

Standards of the National Board of Fire Underwriters for Liquefled Petroleum Gases as recommended by the National Fire Protection

Association shall be deemed to be generally

accepted good practice with respect to the use

of such gases. (See Appendix, par. 910.)

2. Oil-Fired Appliances

Except as may be otherwise provided in law,

in this section, or in duly promulgated regulations, the Commercial Standard for Automatic

Mechanical Draft Oil Bui-ners Designed for Domestic Installations, CS75-39, promulgated

by the United States Department of Commerce

through the National Bureau of Standards, and

the Standards of the National Board of Fire

Underwriters for the Installation of Ofl Burning

Equipment shaU be deemed to be generally

accepted good practice with respect to such

appliances. (See Appendix, par. 910.)

Natural-draft oil burners shall be installed in

accordance with generaUy accepted good practice.

3. Steam and Hot-Water Boilers

Except as may be otherwise provided in law,

in this section, or in duly promulgated regulations, steam and hot-water heating boilers shall conform to the Code for Low Pressure Heating

Boilers of the American Society of Alechanical

Engineers. (See Appendix, par- 910.)

[42]
If.. Automatic Stokers

Except as may be otherwise provided in law,

in this section, or in duly promulgated regulations, the Commercial Standard for Domestic

Burners for Pennsylvania Anthracite, CS48-40,

promulgated by the United States Department

of Commerce through the National Biu'eau of Standards shall be deemed to be generally

accepted good practice with respect to the in- stallation of automatic stokers using anthracite.

The mstallation of other types of automatic

stokers shall be in accordance with generally

accepted good practice. (See Appendix, par.

910.)

Section 911. Combustion

Adequate facilities shall be provided for the entrance of ah to support combustion m rooms

or other spaces enclosing heat appliances, provided that the area of such facilities shall be

not less than the outlet area of the appliances.

CHAPTER X. SAFEGUARDS AGAINST

ACCIDENTS 23

Section 1001. Stairways

All interior stairways, including basement

stairways, shall have handrails on at least one

side. When 44 inches or more in width they

shall have handrails on both sides. All stairways shaU have a minimum head- room of 6 feet 8 inches measured from stairway

treads to construction above.

Section 1002. Steps

Outside steps attached to a dwelling and

containing more than three risers shall have at

least one handrail, provided that this may be

omitted in the case of buUdiead stahs leading

to a basement.

Section 1003. Porches and Terraces

Porches and terraces attached to a dwelling

and with their floors more than 18 inches above

finished grade shall be provided with adequate

railings.

The least dimension of porches and terraces

shall be 3 feet 6 inches.

S3 See Appeuciix, par. 1000.

CHAPTER XI. ELECTRICAL

Section 1100. General

Electric wiring and electric equipment for

light, heat, or power shall conform to generally

accepted good practice.

Section 1101. National Electrical Code

Except as may be otherwise provided in law,

in this chapter, or in duly promulgated regulations, the National Electrical Code, as approved

by the American Standards Association, shall be deemed to be generally accepted good practice. (See Appendix, par. 1101.)

Section 1102. Inspections^

No electric wh-ing shall be covered or concealed until it has been inspected and permission

to conceal has been given by the building official.

CHAPTER XII. PLUMBING

Section 1200. General

Plumbing shall conform to generally accepted

good practice.

Section 1201. Plumbing Standards

Except as may be otherwise provided in law,

ill this chapter, or m duly promulgated regulations, the provisions contained in the report

entitled "Emergency Plumbing Standards for

Defense Housing," issued by the Division of

Defense Housing Coordination, shall be deemed

to be generally accepted good practice. (See

Appendix, par. 1201.)

Section 1202. Sanitary Fixtures

In every dwelling miit in a multiple dwelling

and in every other dwelling unit to which

rmuiiiig water and sewerage are available, there

shall be provided not less than one water closet, one bathtub or shower, one lavatory, and one

kitchen smk. (See Appendix, par. 1202.)

" This section applies in localities where electrical inspection is under

the jm-isdiction of the building official. Where the official is unfamiliar with electrical work, it may be possible to arrange with the electrical inspector of a nearby city to make inspection. Otherwise, it may be

possible to have an inspector sent by the state fire marshal or to accept a report of the representative of the local board of fire underwriters.

[43]
APPENDIX

The information contained in this Appendix is presented to assist in interpreting and enforcing the Code requirements. It consists chiefly of references to useful source material and of detailed acceptable

methods for meeting some of the more general require- ments of the Code. Certain desirable building practices that may be necessary as requirements in certain

localities because of special conditions are also mentioned.

The system of numbering employed in the Appendix

corresponds with that in the Code, the term "Para- graph" being used instead of "Section" as in the Code

itself. Thus, Paragraph 502 of the Appendix deals with some aspect of Section 502 in the Code. Since

it is not necessary to have Appendix matter for every

section in the Code, gaps will be found in the numbering

of paragraphs in the Appendix.

Paragraph 100. General

The address of the American Standards Association,

mentioned in the note on page 7, is 29 West 39th

Street, New York, N. Y. Paragraph 101. Tempoeaby Permits

In general, the requirements of this Code are the minima judged necessary for safety and health and they

apply to structures that are permanent in nature. It

is recognized that in times of great emergency, extraor- dinary measures may be necessary in some places to provide adequate housing accommodations of a temporary nature. To provide for such contingencies, a system of temporary permits is suggested. One of the

objections to permitting so-called "temporary" struc- tures is the difficulty of getting rid of them after the emergency is over. The Code provides for demolition

or removal when this time comes. Paragraph 102. Materials and Methods not

Specifically Authorized

Much emphasis is placed today on so wording build- ing code requirements that new materials and methods

of construction can be utilized without undue delay.

The committee has considered this problem and has come to the conclusion that, for the present at least, the matter is best handled in a general way. As time goes on and performance standards become more definite, it may be possible to carry more specific provisions.

Paragraph 104. Private Water and Sewage-Disposal Systems

The matter of assuring adequate water supply and

sewage disposal, although not customarily dealt with in building codes, is believed to be of major importance.

The publication referred to is a mimeographed document dated May 1941 and bears the title: Sanitation Code for Local Adoption. It is obtainable on application to the United States Public Health Service, Washington, D. C. A revised edition of this document is in preparation.

Paragraph 300. Fire-Resistance Classifications

The classification of buildings given in Chapter III

is based upon recommendations made by the Subcommittee on Fire Resistance Classifications of the Central Housing Committee on Research, Design, and Construction, in a report entitled "Fire Resistance Classifi- cations of Building Constructions," obtainable from the National Bureau of Standards, Washington, D. C. Supplementary provisions which round out the require- ments in this chapter are to be found in Chapter VIII,

Fire Protection. In general, the fire resistance required for walls and

other structural members is made more specific than in many existing building codes and is somewhat reduced

from that customarily required, particularly for fire- proof buildings. The Subcommittee on Fire Resistance

Classifications made its recommendations after a very

careful survey of combustible contents in residential buildings. The requirements are intended to establish a more logical relationship between fire resistance provisions and combustible contents than has prevailed

in the past.

Paragraph 502. Windows

The requirements for glass area in Section 502-2 are based on average conditions and may well be modified

according to latitude. For a discussion of the effect of latitude and of other considerations affecting natural

lighting, see Principle 4, of Basic Principles of Healthful Housing, Second Edition, May 1939. Matters affect- ing ventilation are also discussed in this publication. It

is a report of the Committee on the Hygiene of Housing

of the American Public Health Association, 1790 Broadway, New York, N. Y., and is obtainable from

the association for 25 cents.

Paragraph 502-2. Glass Area

It is recommended that consideration be given to adding the following to the second paragraph of Section 502-2: "provided that in dwelling units where

habitable rooms do not have cross or through ventilation, the aggregate glass area of windows, except in kitchens, shall be not less than }i of the floor area;".

Paragraph 502-4. Screening

Every dwelling which is located in an area in which

flies or mosquitoes have not been efl'ectively controlled should have all windows, ventilating openings, and

doors to the outside equipped with screens of not less than 16 meshes to the inch. All outside screen doors should open outward and be self-closing.

Paragraph 606-3. Lighting and Ventilation

One method of meeting the general requirement for

artificial lighting in Section 606-3 would be to provide an electric-light outlet, centrally located, in every 150 square feet of hall area. In the case of natural light.

[44]
different floor plans require different arrangements of windows in order to provide reasonably uniform distri- bution of light. Consideration should be given to locating windows so that such a distribution will be

afforded, particularly in short sections of hallway

leading off from the main hallway.

Paragraph 700. Quality of Materials

Standards and specifications mentioned in Section 700-1 may be obtained from the following sources:

Specifications of the American Society for Testing

Materials—American Society for Testing Materials, 260 South Broad Street, Philadelphia, Pa. Federal Specifications—Superintendent of Documents, Washington, D. C. Standards of the American Standards Association

American Standards Association, 29 West 39th

Street, New York, N. Y. Commercial Standards—Superintendent of Documents, Washington, D. C.

Paragraph 704. Foundations

The address of the American Wood Preservers'

Association, mentioned in Sections 704-4 and 704-5, is 111 West Washington Street, Chicago, 111.

Paragraph 704-4. Design of Footings

The standards of the Federal Housing Administration, Washington, D. C, contain specific dimensions

in harmony with this requirement.

Paragraph 705. Masonry

The specifications referred to in Section 705-1 are obtainable from the American Society for Testing

Materials, 260 South Broad Street, Philadelphia, Pa., for 25 cents each.

Paragraph 705-1. Quality of Materials

Attention is called to the fact that under the general

requirements of the Code, for quality of materials, the

quality of lime used in lime mortar should conform to

existing ASTM or Federal specifications.

Paragraph 705-15(c). Lintels and Arches

In order to meet the requirements of Section 705-15

(c) for masonry arches, arches built of ordinary masonry

units should have a rise of at least 1 inch for each foot

of span. For flat arches, masonry units must be

specially formed or ground.

Paragraph 706. Reinforced Concrete

The building regulations mentioned in Section 706-1

are obtainable from the American Concrete Institute,

7400 Second Boulevard, Detroit, Mich., for 50 cents.

Paragraph 707. Reinforced Brick Masonry

Principles of Brick Engineering, mentioned in Section

707, may be obtained from Structural Clay Products

Institute, 1756 K Street, N.W., Washington, D. C,

for $4.

Paragraph 708. Steel and Iron

The speciflcation mentioned in Section 708-1 is obtainable from the American Institute of Steel Construction, 101 Park Avenue, New York, N. Y. Information about the use of light steel construction

(see sec. 708-3) is obtainable from the American Iron and Steel Institute, 350 Fifth Avenue, New York, N. Y. The specifications mentioned in Section 708—4 are obtainable from the Steel Joist Institute, 201 North Wells

Street, Chicago, 111. When field welding of steel joists is permitted (see

sec. 708-4), it is recommended that work conform to the requirements of Specification for Structural Steel Welding, No. 22Yb, October 1939, published by the Bureau

of Yards and Docks, Navy Department, and obtainable

from the Superintendent of Documents, Washington, D. C. Paragraph 709-1. General

The Wood Handbook of the United States Department of Agriculture is obtainable from the Superintendent of Documents, Washington, D. C, for 35 cents. In it will be found discussion of various matters affecting

design, including stresses due to wind loads, impact

stresses, shear, compression perpendicular to grain and

on surfaces inclined to grain, and methods of determining allowable working stresses for short, intermediate,

and long columns. Adequate methods of nailing are described in the Wood Handbook and in the following:

Nail-Holding Power of American Woods, Technical

Note No. 236, July 1931; General Observations on the Nailing of Wood,

Technical Note No. 243, August 1940; Nailing Dense Hardwoods, Technical Note No. 247,

April 1941; Timber Fastenings, Separate Reprint from Wood

Handbook.

These four items are obtainable without charge from

Forest Products Laboratory, Madison, Wis. In some cases it may be advantageous to make use

of special timber connectors. These are described in the Wood Handbook.

Paragraph 709-2. Determination of Required Sizes

Information on American Lumber Standards is to be

found in the Wood Handbook of the United States Department of Agriculture, and in Simplified Practice Recommendation R16-39, Lumber: American Lumber

Standards for Softwood Lumber, both obtainable from

the Superintendent of Documents, Washington, D. C,

for 35 and 20 cents, respectively.

[45]
Paragraph 709-3. Working Stresses

Miscellaneous Publication 185, mentioned in Section 709-3, is obtainable from the Superintendent of Documents, Washington, D. C, for 5 cents, and the Supplement thereto, mentioned in the same section, is obtainable without charge from the Forest Products Laboratory, Madison, Wis. For convenience in meeting the requirements of Section 709-3, tables of basic stresses, working stresses, and maximum spans of joists and rafters are presented

here. The tables of working stresses take into account

differences in species, grades, effect of knots, and other

factors. Use of the tables of spans for joists and rafters

will assure compliance with the provisions of Section 709-3.

Table 1.Basic sh

[For material that is contir

In the case of roofs, tables 8 and 8a apply to pitches

at or below 3 in 12, and spans determined by bending

are for roof pitches of roofs which do not support

plastered ceilings ; tables 9 and 9a are for roofs of similar pitch supporting plastered ceilings. Tables 10 and 10a apply to roof pitches between the maximum indicated thereon and a minimum pitch of 3 in 12. They are for roofs having light roofing materials. Tables 11 and 11a apply to roof pitches of 8>^ in 12 and greater and of 10^

in 12 and greater, and are for roofs having light roofing

materials. Tables 12 and 12a apply to roof pitches

between the maximum indicated thereon and a mini- mum pitch of 3 in 12 and are for roofs having heavy

roofing materials. Tables 13 and 13a apply to roof

pitches of 8J4 in 12 and greater and of 10}4 in 12 and

greater, and are for roofs having heavy roofing materials.

\ses for clear material ^

lusly dry or continuously wet]

Species Extreme fiber in bending

Compression

perpendicular

to grain '

Compression

parallel to grain (;/d = ll or less)

Maximum

horizontal shear

Modulus of elasticity

lb/in.' Iblin.' Ib/inJ IblinJ Ash, black .. . . 1,333 300 866 120 1, 100, 000 Ash, commercial white -_- . _ _ . ._ _. . . 1,866 500 1, 466 167 1. 500. 000

1,733 300 1,466 133 1, 200, 000

2 000 500 1 600 167 1 Ron nno

Birch, sweet and yellow _ 2, 000 500 1, 600 167 1,600, 000

Chestnut, American . _ _ _ 1,266 300 1,066 120 1, 000, 000

Douglas-fir, coast region _ __ ___ 2, 000 325 1,466 120 1, 600, 000

Douglas-fir, coast region, close-grained- - . . _ 2. 133 345 1, .565 120 1,600, 000

Douglas-fir, Rocky Mountain region . 1,466 275 1,066 113 1, 200, 000

Douglas-fir, dense, all regions _- . 2, 333 380 1,711 140 1, 600. 000 Elm, American and slippery ' . _ _ 1, 466 250 1, 066 133 1, 200, 000 Elm, rock .__ ___ - __ _._ _. ___ 2,000 500 1,600 167 1, 300, 000

Fir, balsam 1,200 150 933 93 1, 000, 000

Fir, commercial white 1, 466 300 933 93 1, 100, 000 Hemlock, eastern... __ __. 1, 466 300 933 93 1, 100, 000 Hemlock, western ... _ . ... .. _. . _ _ 1,733 300 1, 200 100 1, 400, 000 Hickory, true and pecan ___ _. _ _. _. 2, 533 600 2,000 187 1, 800, 000 Larch, western. __ 6 1, 600 325 1,466 133 1, 300, 000 Maple, sugar and black 6. _ 2, 000 500 1,600 167 1, 600, 000 Oak, commercial red and white___ . _ ._ _ _ _ __ . _____ 1, 866 500 1,333 167 1, 500, 000

Pine, western white,' eastern white, ponderosa, and sugar 1,200 250 1, 000 113 1, 000. 000 Pine, red ________ _ _ _ __ 1,466 300 1.066 113 1, 200, 000

Pine, southern yellow « . 2, 000 325 1,466 146 1, 600, 000

2, 333 380 1, 711 171 1, 600, 000

1,200 200 933 106 1, 000, 000 Redwood. __ _. ... 1,600 250 1, 333 93 1, 200, 000 Redwood, close-grained . ..... 1,707 267 1, 422 93 1, 200, 000 Spruce, Engelmann ... .._ _ __ _ 1,000 175 800 93 800, 000 Spruce, red, white, and Sitka_ _ _ _ _. ' 1,466 260 1, 066 113 1, 200, 000

1,466 300 1,066 133 1, 200, 000 Tamarack

___

__ _ 1,600 300 1,333 126 1, 300, 000 Tupelo 1,466 300 1,066 133 1, 200, 000 White-cedar, northern and Atlantic __ _ 1,000 175 733 93 800. 000

"White-cedar, Port Orford_ __ ___ ._ 1, 466 250 1,200 120 1, 500, 000

1,466 250 1,066 120 1, 200, 000

1 Basic stresses arc for determining design or working stresses according to the grade of timber and conditions of exposure.

' For material that is continuously wet take 70% of these values.

3 Sold as white elm or soft elm.

* Also sold as west-coast hemlock.

« In setting up basic working stresses, consideration has "been given to results of tests on small clear specimens and to tests on full-sized timbers of the species when the latter are available. That the value for stress in extreme fiber of western larch ought to be higher than that listed here is indi- cated by tests of small specimens but is not confirmed by available tests on structural sizes.

8 Sold as hard maple.

' Also sold as Idaho white pine.

8 Also sold as longleaf or shortleaf southern pine. U. S. Department of .A.griculture, Forest Service, Forest Products Laboratory, Madison, Wis., September 19, 1911.

[46]

Table 2.

Working stresses for

[For material used under

Name of association and effective date of grading rules Species Commercial grade name

Beams and stringers ^

Paragraph

reference

Stress in extreme

fiber

Strength

ratio Stress

Stress in horizontal shear

Strength

ratio

California Redwood Association; July 15, 1936.

National Hardwood Lumber Association; 1941.

Northeastern Ltimber Manufacturers Association; Apr. 1, 1938.

Northern Hemlock and Hardwood

Manufacturers Association; June

27, 1941.

Northern Hemlock and Hardwood

Manufacturers Association; July

23, 1941.

Southern Cypress Manufacturers

Association; July 1940.

Redwood (California redwood).

Baldcypress (southern

cypress).

}Eastem spruce.

•Eastem hemlockRed pine (Norway

pine).

Baldcypress (tide- water red cypress).

Southern Pine Association; July

1, 1939.

Longleaf pine.

West Coast Lumbermen's Association; Jan. 1, 1941.

Shortleaf pine

|Douglas-firf Dense select all-heart structural. \Select all-heart structural

fl400# f structural.

1 1100# f structuraL

1 1200# c StructuraL

llOOO# c StructuraL

174

175

212

218

Percent

82

70

8164

Iblin.' 1,400

1, 200

1,400

1, 100

Percent

(1200# f StructuraL

^1100# f StructuraL

ll000# f StructuraL

{'Select structural—

1000 SO

900 SG

800 SG _.

(1000 SG.

900 SO.

[ 800 SG_

23 75 1,100

1,400 lb. f StructuraL

1,100 lb. f StructuraL

1,200 lb. c Structural.

1,000 lb. c structural.

1,400

1,100

Select structural longleaf Prime .structural longleaf. Merchantable structural longleaf.

' Structural square edge and

sound longleaf. No. 1 structural longleaf. No. 1 longleaf dimension No. 2 longleaf—1050F ... /Dense select structural. Dense structural Dense structural square edge and sound. Dense No. 1 structural. No. 1 dense dimension.. No. 1 dimension No. 2 dense 1050F dimension No. 2 medium grain OOOF di-

. mension. {Dense select structuraL

Select structural

1,200 f 900 f

389 392

395

398

401

2,000

1,800 1,600

1,600

1,400

471 474

477

2, 000

1,800

1,600

1,400

218, 302

218 1,800

1,600

1 When timber is used in a wet location or exposed to the weather, the working stresses shall be appropriately reduced. (See U. S. Dept. Agric. Miscellaneous Publication 185, "Guide to the Grading of Structural Timbers and the Determination of Working Stresses.") If the decay hazard is obviously high, treated material or the heartwood of a highly decay-resistant species should be employed.

2 The numbers in this column refer to the paragraph numbers in the association grading rules given.

' Nominal dimensions 5 by 8 inches, and larger.

' Nominal dimensions 2 to 4 inches in thickness by 4 inches and wider.

« Nominal dimensions 4 by 4 inches, and larger (square or approximately square).

» Page number.

' Not applicable to widths 4 inches and less.

[48]
PERIODICALS GAMOT BE RENEWED

For renewal: Call Code l^U or

EM-a-i+OUO, Ext. 7722

USCOMM-NBS-DC

various lumber-association grades

continuously dry conditions]

Joists and planks * Posts and timbers

»

Stress in compression perpendular

to the grain

Modulus of elasticity Stress in extreme fiber Stress in horizontal shear Compression parallel to grain Paragraph

reference

Paragraph

reference

Strength

ratio Stress Strength

ratio Stress Strength

ratio Stress

174 175

114

121

Percent

7264

7169

lb/in.'1,400 1,200

1,400 1,100

Percent

86

86

90

76

lb/in.' 8080

120 100

177 177

Percent Iblin.' lb/in.' 267

267

300 300

300

300

250

250

260

300

300

300

300

300

300

300

300

300

300

300

380

380

380

380

380

380

380

380

380

380

380 380

325 380

325

380

346

325

325

Ib/inJ 1,200,000

1, 200, 000

1,200,000

1, 200,000

1, 200,000

1, 200, 000

1,200,000

1, 200,000

1,200,000

1,100,000

1,100,000

1,100,000

1, 100,000

1,200,000

1,200,000

1,200,000

1, 200, 000

1, 200, 000

1, 200, 000

1, 200, 000

1, 600, 000

1, 600, 000

1, 600,000

1,600,000

1, 600, 000

1. 600, 000

1, 600, 000

1. 600, 000

1, 600, 000

1, 600, 000

1, 600, 000

1, 600, 000

1, 600, 000

1, 600, OOO

1, 600, OOO

1, 600,000

1, 600, 000

1, 600, OOO

1, 600,000

310 316 82

68 1,200

1,000

107

106

105

16 «46

«46

»46

»45 MS

• 45

25

31

7167

63

67

6368

63

6368

53

7169

1,200

1, 100 1,000

1,100

1,000 900 800

1,000 900

800

1,400

1, 100

80

71

71

7660

6050

60

60

60

90

75

90

80

80

704646

46

56

56

56

120 100

31 75 700

82

88

390

393

396

399

402

82

68

85

7670

70

58

1, 200

1,000

1, 450

1,300

1,200

1,200

1,000

388

391 394

397

400

331 333

467

470

473

476

414

413

417

416

214, 302

214 216 216

7468

62

62

67

5645

7468

62

57

6666

45

45

69

69

57

45

2,000

1, 800

1,600

1,600

1, 400

1, 400

1,050

2, 000

1, 800

1, 600

1, 400

1,400

1,200

1,050 900

1, 800

1, 600

' 1,200

' 900

68

68

58

58

68

100 100

100

100

100

68

68

58

58

100 100

100

100

469

472

475

478

85

76

70

58

1,460

1,300

1, 200

1,000

76

75

10690

210, 302

210 80

80

1,300

1,200

U. 8. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, Wis., September 29, 1941.

[49]
Table 3.

Working stresses ' for various

[For material used under

Name of association and effective date of grading rules Oommercial grade name Paragraph

reference 3

California Kedwood Association, May 1940.

National Hardwood Lumber Association, January 1941.

Northeastern Lumber Manufacturers' Association, Apr. 1, 1938. Northern Hemlock and Hardwood Manufacturers' Association, June 27, 1941.

Northern Hemlock and Hardwood Manufacturers' Association, July 23, 1941.

Northern Pine Manufacturers' Association, May 1, 1939.

Port Orford Cedar Lumber Association, Apr. 7, 1939. Southern Cypress Manufacturers' Association, July 1940.

Southern Pine Association, July 1, 1939) _

West Coast Lumbermen's Association, Jan. 1, 1941.

Western Pine Association, Apr. 1, 1939.

Redwood (California redwood).

Baldcypress (cypress)

/Eastern spruce_ \Balsam fir

/Eastern hemlock (Hemlock)

[Tamarack

Eastern white pine (Northern white pine). Red pine (Norway pine) Eastern spruce

'Eastern white pine (Northern white pine) Jack pine Balsam fir Red pine (Norway pine) _ Eastern spruce Tamarack

Port Orford cedar.

Baldcypress (Tidewater red cypress.)

Longleaf pine (Longleaf yellow pine.) Shortleaf pine

(Shortleaf yellow pine.)

Douglas fir

Western hemlock.

Sitka spruce

Western redcedar.

Engelmann spruce Ponderosa pine, sugarpine, western white

pine (Idaho white pine)

Western redcedar (red cedar)

California incense-cedar (Incense-cedar). WcSlarch}(I^-«'^-D*fi^)

White fir

No. 1 Heart common, dimension, joists, and

timbers. No. 2 Common, dimension, joists, and timbers. No. 1 Common

No. 1 (Merchantable) .... No. 1 (Merchantable) No. 1 Common dimension. No. 1 Common dimension No. 1 Dimension and timbers No. 1 Dimension and timbers

|no. 1 Dimension and timbers No. 1 Dimension and timbers |no. 1 Dimension and timbers No. 1 Dimension and timbers

fNo. 1 Common dimension \No. 2 Common

No. 1 Common

No. 2 Dimension.. No. 2 Dimension.

[Select merchantable dimension

•^No. 1 Dimension.

[No. 2 Dimension

(Select merchantable dimension Wo. 1 Dimension. . [No. 2 Dimension

[Select merchantable dimension...

•(No. 1 Dimension.

[No. 2 Dimension.. /No. 1 Dimension, plank and small timber..

l.No. 2 Dimension, plank and small timber.. /No. 1 Dimension

\No. 2 Dimension

/No. 1 Dimension

\No. 2 Dimension.

/No. 1 Dimension

iNo. 2 Dimension.. /No. 1 Dimension

\No. 2 Dimension

/No. 1 Dimension

(No. 2 Dimension

/No. 1 Dimension

\No. 2 Dimension..

1 The working stresses are based on evaluation of the effect of knots (of the sizes permitted by the association grading rules) in accordance with the

principles set forth in TJ. S. Dept. Agric. Miscellaneous Publication 185, "Guide to the Grading of Structural Timbers and the Determination of Working

Stresses" and supplement thereto (issued by the Forest Products Laboratory May 1940). It is assumed that in addition to limitation of knots, other

essentials of strength grading as presented in Miscellaneous Publication 185 and the supplement (such as limitation of decay, slope of grain, shakes, cheeks,

splits, wane and moisture content) are observed.

2 When timber is used in a wet location or exposed to the weather, the working stresses shall be appropriately reduced (see U. S. Dept. Agric. Miscel- laneous Publication No. 185, "Guide to the Grading of Structural Timbers and the Determination of Working Stresses"). If the decay hazard is obviously

high, treated material or the hcartwood of a highly decay-resistant species should be employed.

3 The numbers in this column refer to grading rules given.

' Stresses for Vd = ll or less where d is the least dimension of a solid member or least dimension of each part of a composite member fastened with

nails or other mechanical fastenings. If the parts of a composite member are adequately glued together with water-resistant glue, the composite number may be considered as a solid member.

6 Page number.

[50]
lumber-association grades of dimension

continuously dry conditions] '

Stress in extreme fiber in bending for depths of— Stress * in compression parallel to grain for widtlis of—

i\^odiilLis of elasticity

4 in. 6 in. Sin. 10 in. 12 in. 4 in. 6 in. 8 in. 10 in. 12 in.

Ib/in.i Ib/inJ lb/in.

i

lb/in.' lb/in.2 Ib/in.i tbfin.i lb/in.' Iblin.' 580 970 970 1, 160 1, 110 690 930 1, 050 1,070 1,090

I 1 OfV\ AAn

f

1, /uu, uu*>

1 340 510 610 800 820 430 690 670 770 850 J

620 1, 050 1, 050 1,260 1,200 1,020 1, 300 1,280 1,390 1, 370 1 onn AAA

1, ZUU, UuU

540 750 890 890 1,020 740 870 930 930 1,000 1 OAA AAA

1, ZUU, UUU

440 620 730 730 830 650 760 820 820 870 1, 000, 000

530 660 700 890 890 650 700 730 820 820 1 1 AA AAA

1, iUU, UUU

580 720 770 970 970 930 1,010 1, 050 1, 170 1, 170 1, 300, 000

430 540 580 650 730 DoU 760 780 840 880 1, 000, 000

530 660 700 800 890 740 800 840 900 930 1 OAA AAA

430 540 580 650 730 690 750 780 840 880 1, 000, 000

430 540 580 650 730 650 700 730 790 820 1, 000, 000

530 660 700 800 890 740 800 840 900 930 1, 200, 000

580 720 770 870 Q'7f\ 930 1 010 i, uou 1 130 1 170 1, 300, 000

00\J 890 830 foU 1, 050 1, 050 1, 050

470 730 DDU 620 760 830 960 }

1, 500, 000

620 1 050 1 050 1 260 1 200 1, 020 1 300 1 280 1 390 1 370 1, 200, 000

490 540 510 540 540 OOU 880 860 860 860 1, 600, 000

420 460 440 460 460 750 760 730 730 730 1, 600, 000

1 240 1 420 1 510 1 570 1 600 1 390 1 440 1 460 1 480

720 1 030 1 200 1 200 1 190 1 280 1 280 1 280 > 1, DUU, UOU

420 640 740 800 900 / ou 930 1 020 1 060 1 110

1 360 1, 070 1 140 980

] 080 1 230 1 180 1 190 890

1 310 1 390 1 210 1 Ron 1 050 1 050 830 1 050 1 050 1 050 \ 1, 400, 000

360 1 550 640 690 780 620 760 830 870 910

910 1 040 1 110 1 150 8901 170 you 1 010 1 040 1 060 1 080 1 530 750 890 890 '7Af\ /1U 870 930 930 930 \ 1, 200, 000

OiU 470 1 540 590 DDU 550 680 740 770 800

430 730 730 730 730 DOU 830 820 820 790

250 380 440 480 640 480 590 650 680 700 > 1, UOU, 000

360 450 480 540 600 560 600 630 680 700

100 230 290 340 370 260 410 480 520 560 }

800, 000

430 540 580 650 730 700 760 780 840 880 1 1, 000, 000 120 280 350 410 440 320 520 600 650 700 / 430 540 580 650 730 650 700 730 790 820

120 280 350 410 440 300 480 560 610 650 }

1, 000, 000

430 540 580 650 730 700 760 780 840 880

I

800, 000 120 280 350 410 440 320 520 600 650 700

530 660 700 800 890 740 800 840 900 930

150 340 420 500 540 340 550 640 690 740 }

1, 200, 000

530 660 700 800 890 650 700 730 790 820

1

1, 100, 000

150 340 420 500 540 300 480 560 610 650

U. S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, Wis., revised February 10, 1942

[51]
Tablk 4.

Maximum spans ^ for floor joists of one- [

[45 lb/ft.> total live

Size {nominal) Spacing

Span limited by deflection when modulus of elasticity it pounds per square inch is

Span 2 determined by bending when fiber stress in poimds

per square inch is

1,000,000 1,100,000 1,200,000 1,400,000 1,600,000 200 300 400 500 600

in. in. ft9

in. ft9

in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 112 8 8 IL::::.::

8 11 10 3 10 9 ii 3 5 0 6 2 7 2 8 0 2X6 8 9 9 0 9 4 9 9 10

8

3 4 4 5 4 6 2 6 11

8

7 7

[2i--- - .- 7 8 7 11 8 1 8 7 11 3 7 4 4 5 0 5 6 2

fl2 12 10 13 3 13 8 14 4 15 0 6 9 8 3 9 6 10 7 11 8 2X8 16 11 8 12 0 12 5 13 1 13 8 5 10 7 2 8 3 9 2 10 1 10 2 10 6 10 10 U 5 11 11 4 9 5 10 6 9 7 6 8 3

fl2 16 3 16 9 17 3 18 2 19 0 8 6 10 5 12 0 13 5 14 9 2X10 le::::::::: 14 9 15 3 15 8 16 6 17 3 7 4 9 0 10

8

5 119

8 12 9

124 12 11 13 4 13 9 14 5 15 1 6 0 7 4 6 6 10 5

fl2 19 8 20 4 20 11 22 0 23 0 10 4 12 7 14 7 16 3 17 10 2X12 le::::;;::: 17 11 18 6 19 0 20 0 20 11 8 11 10 11 12 7 14 1 15 5

124 15 7 16 2 16 7 17 6 18 3 7 3 8 11 10 4 11 6 12 7

fl2 23 1 23 10 24 7 25 10 27 0 12 1 14 10 17 1 19 1 20 11 2X14 le::::::::: 21 0 21 8 22 4 23 6 24 7 108

6 12 10 14 10 16 7 18 2

124 18 4 18 11 19 6 20 6 21 5 7 10 6 12 1 13 6 14 10

fl2 11 4 11 8 12 0 12 8 13 3 6 5 7 10 9 1 10 2 11 1 3X6- le::::::::: 10

9

3 10 7 10

9

11 11 6 12 0 5 7 6 10 7 10 8 9 9 7

124 0 9 3 6 10 0 10 6 4 6 5 7 6 5 7 2 7 10

fl2 15 1 15 7 16 0 16 10 17 7 8 6 10 6 12 1 13 6 14 9 3X8 Je::::::::: 13 8 14 2 14 7 15 4 16 0 7 5 9 1 10

8

5 11

9

8 12 10

(24 11 11 12 4 12 8 13 4 14 0 6 0 7 5 6 7 10 6

(12 19 1 19 8 20 3 21 4 22 4 10 10 13 3 15 4 17 1 18 9 3X10 16 17 4 17 118

18 5 19 5 20 3 9 4 119

6 13 3 14 10 16 3

l24 15 2 15 16 1 16 11 17 9 7 8 4 10 10 12 1 13 3

(12 23 1 23 10 24 7 25 10 27 0 13 1 16 0 18 6 20 8 22 8 3X12 16 21 0 21 8 22 4 23 6 24 7 119

4 13 11 16 0 17 118

19 8 i24.-_-.-.. 18 4 18 11 19 6 20 6 21 5 3 11 4 13 1 14 16 0 (12—- 27 1 28 0 28 10 30 4 31 9 15 4 18 10 21 9 24 4 26 7 3X14 ]l6 24 8 25 6 26 2 27 7 28 10 13 4 16 4 18 10 21 1 23 1 l24— - 21 6 22 3 22 10 24 1 25 2 10 10 13 4 15 4 17 2 18 10

1 This table is based on FHA design recommendations as follows:

(a) Where fiber stress is the controlling factor, the assumed total design load is 45 Ib/ft^. For first floors of 1- and 2-story houses and for all floors of multiple dwellings, it is assumed that the superimposed load is 40 ihjtP and the dead load 5 Ib/ft^; for second floors of 2-story houses the super- imposed load is 30 Ib/ft^ and the dead load 15 Ib/ft^. These loading assumptions permit the same design load basis for first and second floors, and for multiple dwellings where plaster is not used.

(b) When deflection is the controlling factor, the deflection limitation of 1/360 of the span is based on an assumed total load of 40 Ib/ft^ for both the

first and second floors, and for multiple dwellings.

2 Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

[52]
and two-story houses and of multiple dwellings

and dead load]

Span ' determined by bending when fiber stress in pounds per square inch is—Continued

700 800 900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 9 5 10 1 10 8 11 3 11 10 12 4 12 10 13 4 13 10 14 3 14 8 15 1 g 2 8 9 9 3 9 9 10 3 10 8 11 2 11 7 11 11 12 4 12 9 13 1 6 8 7 2 7 7 8 0 8 4 8 9 9 1 9 5 9 9 10 1 10 5 10 8

12 7 13 5 14 3 15 0 15 9 16 5 17 2 17 9 18 5 19 0 19 7 20 2 10 11 11 8 12 4 13 0 13 8 14 3 14 10 15 5 15 11 16 5 17 0 17 5

8 11 9 6 10 1 10 7 11 2 11 8 12 1 12 7 13 0 13 5 13 10 14 3

15 11 17 0 18 1 19 0 19 11 20 10 21 8 22 6 23 4 24 1 24 10 25 6

13 9 14 9 15 8 16 6 17 18 1 18 9 19 6 20 2 20 10 21 6 22 1 11 3 12 0 12 9 13 5 14 1 14 9 15 4 15 11 16 6 17 0 17 7 18 1

19 3 20 21 10 23 0 24 25 3 26 3 27 3 28 3 29 2 30 0 30 11 16 8 17 10 18 11 19 11 20 11 21 10 22 9 23 7 24 5 25 3 26 0 26 9 13 8 14 16 5 16 3 17 17 10 18 7 19 3 19 11 20 7 21 3 21 10

22 8 24 25 8 27 1 28 29 7 30 10 32 0 33 1 34 2 35 3 36 3 19 7 20 11 22 3 23 5 24 25 8 26 8 9 28 8 29 7 30 6 31 5 16 0 17 18 2 19 1 20 1 20 11 21 10 22 8 23 5 24 2 24 11 25 8

12 0 12 10 13 7 14 4 15 0 15 8 16 4 16 11 17 6 18 1 18 8 19 3 10 5 11 11 9 12 5 13 0 13 7 14 2 14 8 15 2 15 8 16 2 16 8

8 6 9 9 7 10 2 10 7 11 1 11 7 12 0 12 5 12 10 13 2 13 7

16 0 17 18 1 19 1 20 0 20 11 21 9 22 7 23 5 24 2 24 11 25 13 10 14 15 8 16 6 17 4 18 1 18 10 19 7 20 3 20 11 21 7 22 2

11 4 12 12 10 13 6 14 2 14 9 15 5 16 0 16 6 17 1 17 7 18 1

20 3 21 8 22 11 24 2 25 4 26 6 27 7 28 7 29 7 30 7 31 6 32 5 17 6 18 9 19 10 20 11 22 0 22 11 23 11 24 9 25 8 26 6 27 4 28 1 14 4 15 4 16 3 17 1 17 11 18 9 19 6 20 3 20 11 21 8 22 4 22 11

24 6 26 2 27 9 29 3 30 8 32 1 33 5 34 8 35 10 37 0 38 2 39 3 21 3 22 8 24 1 25 4 26 7 27 9 28 11 30 0 31 1 32 1 33 1 34 0

17 4 18 6 19 8 20 8 21 9 22 8 23 7 24 6 25 4 26 2 27 0 27 9

28 9 30 9 32 7 34 4 36 1 37 8 39 2 40 8 42 1 43 6 44 10 46 1 24 11 26 7 28 3 29 9 31 3 32 7 33 11 35 3 36 5 37 8 38 10 39 11 20 4 21 9 23 1 24 4 25 6 26 27 9 28 9 29 9 30 9 31 8 32 7

U. S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, Wis., September 29, 19il:

revised December 15, 19U.

[S3]
Table 5.

Maximum spans ' for

[65 Ib/fta total live

Span limited by deflection when modulus of elasticity in Span 2 determined by bending when fiber stress in pounds

Size Spacing pounds per square inch is

per square inch is- (nominal)

1,000,000 1,100,000 1,200,000 1,400,000 1,600,000 200 300 400 500 600

in. in. ft in. in. ft in. /« in. ft in. ft in. ft in. 6

in. ft in. ft in. (12 g g 10 3 10 g \l 3 4 7 5 7 5 7 2 7 11 2X6 16 - g Q Q g g 9 10 3 3 11 4 10 5 7 6 3 6 10 (a 7 8 7 11 8 1 8 7 8 11 QO O 3 11 4 7 5 1 6 7

fl2 12 10 13 13 g 14 15 Q 6 1 7 6 8 7 9 7 10 6 2X8 16 11 8 12 0 12 5 13 1 13 8 6

QO 6 5 7 5 8 4 9 1 10 2 10 6 10 10 11 5 11 11 4 5 3 6 1 6 10 7 6

(12 16 16 17 18 2 19 Q 7 8 9 5 10 11 12 2 13 4 2X10 16 14 Q 15 15 g 16 17 3 6 8 8 2 9 5 10

8 6 11 7

12 11 13 4 13 9 14 5 15 1 0 5 6 g 7 8 7 9 5

(12 _ 19 QO 20 20 11 22 u 23 0 9 4 11 5 13 2 14 9 16 2 2X12.. ._ 16 17 18 g 19 Q 20 Q 20 8 1 9 11 11 5 12 9 14 0

('^ 15 7 16 2 16 7 17 6 18 3

ftU71 8 1 9 4 10 5 11 5

(12 23 23 10 24 25 10 27 Q 10 11 13 5 16 6 17 4 18 11 2X14-. 16 A

u 21 QO 22 23 g 24 y 9 6 11 7 13 5 15 0 16 5 9A 18 4 18 11 19 6 20 6 21 5

7 9 9 6 10 11 12 3 13 6

(12 11 A 11 Q 1 o U

1 0 QO1 Q qo 5 10 7 1 8 2 9 2 10 0 3X6 16 lU QO in 7

9

11 D 12 n

6

5 0 6 2 7 1 7 116

8 8 94 9 0 9 3 6 10 0 10 1 5 0 5 10 6 7 1

(12 15 1 15 7 16 0 16 10 17 7 7 9 9 6 10 11 12 3 13 5 3X8 ]16 - 13 8 14 2 14 7 15 4 16 0 6 8 8 2 9 6 10 7 11 7

104 1/4 11 11 12 4 12 8 13 4 14 0 0 6 6 8 7 9 8 8 9 6

(12 19 1 19 8 20 3 21 4 22 4 9 9 12 0 13 10 15 6 16 11 3X10.. 16 - 17 4 17 11 18 5 19 5 20 3 8 6 10 5 12 0 13 5 14 8

l24 15 2 15 8 16 1 16 11 17 9 6 11 8 6 9 9 10 11 12 0

|12 23 1 23 10 24 7 26 10 27 0 11 10 14 6 16 9 18 9 20 6 3X12__ he 21 0 21 8 22 4 23 6 24 7 10 3 12 7 14 6 16 3 17 9

l24 18 4 18 11 19 6 20 6 21 5 8 4 10 3 11 10 13 3 14 6

(12 27 1 28 0 28 10 30 4 31 9 13 11 17 0 19 8 22 0 24 1 3X14- - 16 - - 24 8 25 5 26 2 27 7 28 10 12 0 14 9 17 0 19 0 20 10

l24 - 21 6 22 3 22 10 24 1 26 2 9 10 12 0 13 11 15 7 17 0

1 This table is based on FHA design recommendations as follows:

(a) When fiber stress is the controlling factor, the assumed total design load is 56 lb/ft', composed of 40 lb/ft' superimposed load for all floors, and

15 lb/ft' dead load for joists and plaster.

(b) When deflection is the controlling factor, the deflection limitation of 1/360 of the span is based on an assumed total load of 40 Ib/ft^. Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

[S4]
floor joists of multiple dwellings

and dead load]

Span ' determined by bending when fiber stress in pounds per square inch is—Continued

700 800 900 1,000 1,100 1,200 1,300 1,400 1,600 1,600 1,700 1,800

ft in ft in ft in ft

J'' in ff J'' in ff in ft in ft in ft in ft in ft in It in

6 l" 9 S 10 2 10 8 11 2 11 i 12 i 12 e' 12 U 13

3' 13 8

7 5 7 11 8 4 8 10 9 3 9 8 10 1 10 5 10 10 11 2 11 6 11 10

Q 0 g 5 g 10 7 2 7 7 7 11 g 3 g g g 10 9 1 9 5 9 g

11 4 12 2 12 11 13 7 14 3 14 11 15 6 16 1 16 8 17 2 17 9 18 3 9 10 10 6 11 2 11 9 12 4 12 U 13 5 13 11 14 5 14 11 16 4 15 9

g 0 g 7 9 1 9 7 10 1 10 g 10 11 11 4 11 9 12 2 12 g 12 11

14 5 15 5 10 4 17 3 18 1 18 10 19 7 20 4 21 1 21 9 22 5 23 1 12 6 13 4 14 2 14 11 15 8 16 4 17 0 17 8 18 3 18 10 19 5 20 0

10 2 10 11 11 7 12 2 12 9 13 4 13 11 14 5 14 11 15 5 15 10 16 4

17 5 18 8 19 9 20 10 21 10 22 10 23 9 24 8 25 6 26 4 27 2 27 11 10 16 2 17 1 18 1 18 11 19 9 20 7 21 4 22 1 22 10 23 g 24 0 12 4 13 2 14 0 14 9 15 5 16 2 16 10 17 5 18 1 18 g 19 3 19 9

20 6 21 11 23 2 24 6 25 8 26 10 27 11 28 11 29 11 30 11 31 11 32 10

17 9 18 11 20 1 21 2 22 3 23 2 24 2 25 1 25 11 26 10 27 7 28 5 14 g 15 g 16 5 17 4 18 2 18 11 19 9 20 g 21 2 21 11 22 7 23 2

10 10 11 7 12 3 12 11 13 7 14 2 14 9 15 4 15 10 16 5 16 11 17 5 9 5 10 0 10 8 11 3 11 9 12 3 12 9 13 3 13 9 14 2 14 8 15 1 7 8 8 2 8 8 9 2 9 7 10 0 10 5 10 10 11 3 11 7 11 11 12 3

14 5 15 5 16 5 17 3 18 1 18 11 19 8 20 5 21 2 21 10 22 6 23 2

12 6 13 5 14 2 14 11 15 8 16 5 17 1 17 8 18 4 18 11 19 6 20 1 10 3 10 11 11 7 12 3 12 10 13 5 13 11 14 5 14 11 15 5 15 11 16 6

18 4 19 7 20 9 21 11 22 11 24 0 24 11 25 11 26 10 27 8 28 6 29 4 16 10 16 11 18 0 18 11 19 10 20 9 21 7 22 5 23 2 24 0 24 8 25 5 12 11 13 10 14 8 15 6 16 3 16 11 17 8 18 4 18 11 19 7 20 2 20 9

22 2 23 8 25 1 26 6 27 9 29 0 30 2 31 4 32 5 33 6 34 6 35 6

19 2 20 6 21 9 22 11 24 1 25 1 26 2 27 2 28 1 29 0 29 11 30 9

15 8 16 9 17 9 18 9 19 8 20 6 21 4 22 2 22 11 23 8 24 5 25 1

26 0 27 10 29 6 31 1 32 7 34 1 35 5 36 9 38 1 39 4 40 6 41 8

22 6 24 1 25 6 26 11 28 3 29 6 30 8 31 10 33 0 34 1 35 1 36 1 18 5 19 8 20 10 22 0 23 1 24 1 25 1 26 0 26 11 27 10 28 8 29 6

U. S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, Wis., September 29, 1941;

revised December 15, 1941.

[SS]
Table 6.

Maximum

[10 lb/ft2 total

Spacing

tn. (1216.....

[24.....

(12..... he

124.....

(12..... 16

l24.....

(12..... 16.....

l24.....

12

1624

Span limited by deflection when modulus of elasticity in pounds per square inch is

Span ' determined by bending when fiber stress in pounds

per square inch is

)00,000 1,100,000 1,200,000 1,400,000 1,600,000 200 300 400 500 600

jt m. in. ft in. ft in. ft in. ft in. ft8

in. ft in. ft in. ft in. Qy

1 n 10 2 10 6 11 0 11 6 6 11 5 9 9 10 11 11 11 8 11 9 3 9 6 10 0 10 6 6 0 7 4 8 5 9 5 10 4

7 10 8 1 8 4 8 9 9 2 4 10 6 0 6 11 7 g g 5

15 3 15 9 16 3 17 1 17 11 10 8 13 1 15 1 16 11 18 6

13 11 14 4 14 9 15 6 16 3 9 3 11 4 13 1 14 8 16 0

12 2 12 6 12 11 13 7 14 2 7 7 9 3 10 8 11 11 13 1

20 5 21 0 21 8 22 10 23 10 14 3 17 5 20 2 22 6 24 8

18 6 19 1 19 8 20 9 21 8 12 4 15 1 17 5 19 6 21 5 16 2 16 8 17 2 18 1 18 11 10 1 12 4 14 3 15 11 17 5

25 10 26 8 27 5 28 11 30 2 18 1 22 1 25 6 28 7 31 3 23 5 24 3 24 11 26 3 27 5 15 8 19 2 22 1 24 9 27 1 20 6 21 2 21 9 22 11 24 0 12 9 15 8 18 1 20 2 22 1

31 3 32 3 33 2 34 11 36 7 21 10 26 9 30 11 34 7 37 10

28 6 29 4 30 2 31 9 33 2 18 11 23 2 26 9 29 11 32 9 24 10 25 7 26 4 27 9 29 0 15 5 18 11 21 10 24 5 26 9

1 This table is based on FHA design recommendations as follows:

(a) Where the fiber stress is the controlling factor, the assumed total design load is 10 lb/ft'. (b) When deflection is the controlling factor, the deflection limitation of 1/360 of the span is based on an assumed total load of 10 lb/ft'.

> Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

Table 7.

Maximum spans^

[30 lb/ft' total live and dead

Span limited by deflection when modulus of elasticity in Span ! determined by bending when fiber stress in pounds

Size Spacing pounds per square inch is

per square inch is- (nominal)

1,000,000 1,100,000 1,200,000 1,400,000 1,600,000 200 300 400 600 600

in. in. ft in. in. ft8

in. ft8in. ft in. ft in. ft in. ft in. ft6

tn. ft in.

(12 7 10 1 4 9 9 2 4 0 4 10 5 8 3 6 11 2X4 16 7 1 7 4 7 7 7 11 8 4 3 5 4 3 4 10 5 5 6 0

[24 6 2 6 5 6 7 6 11 7 3 2 10 3 5 4 0 4 5 4 10

(12 - 12 2 12 6 12 11 13 7 14 2 6 2 7 7 8 9 9 9 10 8 2X6 ]l6 11 0 11 5 11 9 12 4 12 11 5 4 6 7 7 7 8 5 9 3

[24 .- 9 8 9 11 10 3 10 9 11 3 4 4 5 4 6 2 6 11 7 7

|12 — 16 2 16 8 17 2 18 1 18 11 8 3 10 1 11 8 13 0 14 3 2X8 16 14 8 15 2 15 7 16 5 17 2 7 2 8 9 10

8

1 1193 12 4

[24 12 10 13 3 13 8 14 4 15 0 5 10 7 2 3 2 10 1

(12 - 20 6 21 2 21 9 22 11 24 0 10 5 12 9 14 9 16 6 18 1 2X10 16 18 7 19 3 19 9 20 10 21 9 9 0 11 1 12 9 14 3 15 8

[24 16 3 16 9 17 3 18 2 19 0 7 4 9 0 10 5 11 8 12 9

(12 - 24 10 25 7 26 4 27 9 29 0 12 7 15 5 17 10 19 11 21 10 ^X12 ]l6 22 6 23 3 23 11 25 2 26 4 108

11 13 5 15 5 17 3 18 11 24 19 8 20 4 20 11 22 0 23 0 11 10 11 12 7 14 1 16 5

1 This table is based on FHA design recommendations as follows:

(a) When fiber stress is the controlling factor, the assumed total design load is 30 Ib/ft^, comprised of 20 lb/ft' superimposed load and 10 lb/ft' •dead load.

(b) When deflection is the controlling factor, the deflection limitation of 1/360 of the span is based on an assumed total load of 20 lb/ft».

' Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

[56]
'ispans ' for ceiling joists

koad (no storage)]

Span ' determined by bending when fiber stress in pounds per square inch is—Continued

700 800 900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 12 11 13 9 14 7 15 5 16 2 16 11 17 7 18 3 18 10 19 6 20 1 20 8

11 2 11 11 12 8 13 4 14 0 14 7 15 3 15 9 16 4 16 11 17 5 17 9

9 2 g 9 10 4 10 11 5 11 11 12 5 12 11 13 4 13 Q 14 2 14 7

20 0 21 5 22 8 23 11 25 1 26 2 27 3 28 3 29 3 30 3 31 2 32 1 17 4 18 6 19 8 20 8 21 9 22 8 23 7 24 6 25 4 26 2 27 0 27 9

14 2 15 1 16 0 16 11 17 9 18 6 19 3 20 0 20 8 21 5 22 0 22 8

26 8 28 6 30 3 31 10 33 6 34 11 36 4 37 8 39 0 40 4 41 7 42 9 23 1 24 8 26 2 27 7 28 11 30 3 31 6 32 8 33 10 34 11 36 0 37 0

18 10 20 2 21 5 22 6 23 8 24 8 25 8 26 8 27 7 28 6 29 6 30 3

33 9 36 1 38 4 40 4 42 4 44 3 46 0 47 9 49 5 61 6 62 8 54 2 29 3 31 3 33 2 34 11 36 8 38 4 39 10 41 4 42 10 44 3 45 7 46 11 23 11 26 6 27 1 28 7 29 11 31 3 32 7 33 9 34 11 36 1 37 3 38 4

40 11 43 8 46 4 48 10 51 3 53 6 55 9 57 10 59 10 61 10 63 9 66 7 3S 5 37 11 40 2 42 4 44 5 46 4 48 3 50 1 51 10 53 6 55 2 66 9 28 11 30 11 32 9 34 7 36 3 37 10 39 5 40 11 42 4 43 8 45 1 46 4

U. S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, Wis., September 29, 1941;

revised December 15, 1941.

for ceiling joists

load (liglit storage)]

Span > determined by bending when fiber stress in pounds per square inch is—Continued

700 800 900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

in. in. in. ft8

in. in. ^1in. ft in. ft in. ft in. ft in. ft. in. ft in. 6 11 5 11 4 9 10 2 10 6 10 11 11 3 11 7 11 11 6 6 6 11 7 4 7 8 8 1 8 5 8 9 9 1 9 5 9 9 10 1 10 4 5 3 5 8 6 0 6 3 6 7 6 11 7 2 7 5 7 8 7 11 8 2 8 5

11 7 12 4 13 1 13 10 14 6 15 1 16 9 16 4 16 11 17 5 18 0 18 6

10 0 10 8 11 4 11 11 12 6 13 1 13 8 14 2 14 8 15 1 16 7 16 0

8 2 8 9 9 3 9 9 10 3 10 8 11 2 11 7 11 11 12 4 12 9 13 1

15 5 16 5 17 5 18 5 19 4 20 2 21 0 21 9 22 6 23 3 24 0 24 8 13 4 14 3 16 1 15 11 16 9 17 5 18 2 18 10 19 6 20 2 20 9 21 5 10 11 11 8 12 4 13 0 13 8 14 3 14 10 15 5 15 11 16 6 17 0 17 5

19 6 20 10 22 1 23 4 24 5 25 6 26 7 27 7 28 7 29 6 30 5 31 3 16 11 18 1 19 2 20 2 21 2 22 1 23 0 23 11 24 9 25 6 26 4 27 1 13 9 14 9 15 8 16 6 17 3 18 1 18 9 19 6 20 2 20 10 21 6 22 1

23 7 25 3 26 9 28 3 29 7 30 11 32 2 33 5 34 7 36 8 36 9 37 10 20 5 21 10 23 2 24 5 25 8 26 9 27 10 28 11 29 11 30 11 31 10 32 9

16 8 17 10 18 11 19 11 20 11 21 10 22 9 23 7 24 5 25 3 26 0 26 9

U. S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madisonj Wis., September 29, 1941;

revtsed December 16, 1941.

[57]
Table 8.

Maximum spans ' for roof joists and rafters for

[For localities where maximum

Size (nominal)

2X4_

2X6.

2X8.

2X10

Spacing

m

|12- -..

16

l24- —

(1216 —

[24

(12 -.

]l6- —

[24

12

16.. 24...

Span 2 determined by bending when fiber stress in pounds per square inch is200

ft in. i 0

300

ft in. 4 10

4 3 3 5

76

5

10

8

7

12

11

400

ft in. 5 8

1412

10

500

ft in. 6 4

600

ft in. 6 11 6 0

4 10

10 8

9 3

7 7

700

ft in. 7

"

6

5

19 6 16 11 13 9

1 This table is based on FHA design recommendations as follows;

(a) The total assumed design load is 30 Ib/ft^, composed of 20 Ib/ft^ live load and 10 lb/ft' dead load.

(b) All loads are considered to be acting vertically.

(c) Span is the horizontal projection of the rafter between supports.

' Maximum spans for fiber stresses which are between those tabulated shall be determined by interpolation. Table 8a.

Maximum spans ^ for roof joists and rafters

[For localities where maximum

Size (nominal) Spacing

(1216

l24

(1216

l2412

1624

(12 ]l6-

[24

Span ' determined by bending when fiber stress in pounds per square inch is200 300 400 500 600 700 800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. 3 5 4 3 4 11 5 5 6 0 6 5 6 11 3 0 3 8 4 3 4 9 5 2 5 7 6 0

2 6 3 0 3 5 3 11 4 3 4 7 4 10

5 4 6 7 7 7 8 6 9 3 10 0 10 8

4 8 5 8 6 7 7 4 8 -1 8 8 9 3

3 10 4 8 6 4 6 0 6 7 7 1 7 7

7 2 8 9 10 1 11 3 12 4 13 4 14 3 6 3 7 8 8 9 9 10 10 9 11 7 12 4

5 1 6 2 7 2 8 0 8 9 9 5 10 1

9 0 11 1 12 9 14 4 15 g 16 11 18 1 7 10 9 8 11 1 12 5 13 7 14 7 16 8

6 4 7 10 9 0 10 1 11 1 11 11 12 9

1 This table is based on FHA design reconmiendations as follows:

(a) The total a-ssmned design load is 40 Ib/ft^, composed of 30 Ib/ft* live load and 10 lb/ft* dead load.

(b) All loads are considered to be acting vertically.

(c) Span is the horizontal projection of the rafter between supports.

' Maximimi spans for fiber stresses which are between those tabulated shall be determined by interpolation.

[58]
slopes of S in 12 and less, not supporting plastered ceiling

live load is 20 Ib/ft^]

Span ! determined by bending when fiber stress in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

7'8

ft ff ft 7' ft in. ft m.

6 8 11 9 4 9 9 10 2 10 6 10 11 11 3 11 7 11 7 4 7 8 8 1 8 5 8 9 9 1 9 5 9 9 10 1 10 4 6 0 6 3 6 7 6 11 7 2 7 5 7 8 7 11 g 2 8 6

13 1 13 10 14 6 15 1 15 9 16 4 16 U 17 6 18 0 18 6

11 4 11 11 12 6 13 1 13 8 14 2 14 8 15 1 15 7 16 0

9 3 9 9 10 3 10 8 11 2 11 7 11 11 12 4 12 9 13 1

17 5 18 5 19 4 20 2 21 0 21 9 22 6 23 3 24 0 24 8

16 1 15 11 16 9 17 5 18 2 18 10 19 6 20 2 20 9 21 6 12 4 13 0 13 8 14 3 14 10 16 5 15 n 16 5 17 0 17 6

22 1 23 4 24 5 25 6 26 7 27 7 28 7 29 6 30 5 31 3 19 2 20 2 21 2 22 1 23 0 23 11 24 9 25 6 26 4 27 1 16 8 16 6 17 3 18 1 18 9 19 6 20 2 20 10 21 6 22 1

for slopes of S in 12 and less, not supporting plastered ceiling

live load is 30 Ib/ft^]

Span 2 determined by bending when fiber stress in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 7 4 7 8 8 1 8 6 8 9 9 1 9 5 9 9 10

8

1 10

8

4 6 4 6 8 7 0 7 4 7 7 7 11 8 2 8 6 8 11 6 2 5 5 6 9 6 0 6 3 6 5 6 8 6 11 7 1 4

11 4 11 11 12 6 13 1 13 8 14 2 14 8 15 1 16 7 16 0 9 10 10 4 10 10 11 4 11 10 12 3 12 8 13 1 13 6 13 11 8 0 8 0 8 10 9 3 9 8 10 0 10 4 10 8 11 0 11 4

15 1 15 11 16 9 17 5 18 2 18 10 19 6 20 2 20 9 21 5 13 1 13 10 14 6 15 1 15 9 16 4 16 11 17 6 18 0 18 6 10 8 11 3 11 10 12 4 12 10 13 4 13 10 14 3 14 8 16 1

19 2 20 2 21 2 22 1 23 0 23 11 24 9 25 6 26 4 27 1 16 7 17 6 18 4 19 2 19 11 20 8 21 6 22 1 22 9 23 5 13 6 14 3 15 0 15 8 16 3 16 11 17 6 18 1 18 7 19 2

[59]
Table 9.

Maximum spans ' for roof joists and rafters

[For localities where maximum

Span limited by deflection when modulus of elasticity in bpan determined by bendins; when fiber stress in pounds

Size Spacing pounds per square mch is

per square inch is- (nominal)

1,000,000 1,100,000 1,200,000 1,400,000 1,600,000 200 300 400 500 600

in. in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in.

112 7 10 8 1 8 4 8 9 9 2 3 5 4 3 4 11 6 5 6 0 2X4 ^6 - 7 1 7 4 7 7 7 11 8 4 3 0 3 g 4 3 4 9 5 2

l24 6 2 6 5 6 7 6 11 7 3 2 6 3 0 3 5 3 11 4 3

(12 12 2 12 6 12 11 13 7 14 2 5 4 6 7 7 7 8 6 9 3 2X6_ ^6 __ 119

0 1195 11 9 12 4 12 11 4 8 5 8 6 7 7 4 8 1 8 11 10 3 10 9 11 3

9o 10 4 8 5 4 6 0 6 7

(12 16 2 16 8 17 2 18 1 18 11 7 2 8 9 10 1 11 3 12 4 2X8 16 - 14 8 15 2 15 7 16 5 17 2 6 3 7 8 8 9 9 10 10 9

l24 12 10 13 3 13 8 14 4 15 0 5 1 6 2 7 2 8 0 8 9

(12 20 6 21 2 21 9 22 11 24 0 9 0 11 1 12 9 14 4 15 8 2X10 16 - 18 7 19 3 19 9 20 10 21 9 7 10 9 8 n

9

1 12 5 13 7

l24 — 16 3 16 9 17 3 18 2 19 0 6 4 7 10 0 10 1 11 1

1 This table is based on FHA design recommendations as follows:

(a) When fiber stress is the controlling factor, the assumed total design load is 40 Ib/ft^, composed of 20 lb/ft' live load and 20 Ib/ft^ dead load.

(b) When deflection is the controlling factor, i. e., when joists or rafters support a finished ceiling, the deflection limitation of 1/360 of the span is based on an assumed total load of 20 lb/ft*. (c) All loads are considered to be acting vertically.

(d) Span is the horizontal projection of the rafter between supports.

> Maximum spans for fiber stresses which are between those tabulated shall be determined by interpolation.

Table 9a.Maximum spans ' for roof joists and rafters

[For localities where maximum

Spacing

Span limited by deflection when modulus of elasticity in pounds per square inch is

1,000,000

in. (12 |l6 ..... 124 ....

(12 .... 16 ....

l24 ....

(12 .... {l6 ....

l24 ....

(12 .... ]l6 .... 24 ....

ft in. 6 10 6 2

5 4

10 7

14 2

12 10

11 3

17 11 16 3 14 2

1,100,000 1,200,000 1,400,000 1,600,000

ft in. 7 1 6 5 5 6

10 11 9 11

14

13

11

1816

14

ft in. 7 3

6 7

5 9

15 0

13 8

11 11

19

17

15

ft in.

7 8

6 11 6 1

11 10

10 9

15 10

14 4

20

18

ft in.

8 0

20 11 19 0

Span 2 determined by bending when fiber stress in pounds

per square inch is

200

ft in.

3 1 2 8

2 2

300

ft in. 3 9

3 3

2 8

400

ft in. 4 4

3 9

3 1

6 9

5 10

4 9

9 0

7 10 6 5

11 5 9 11 8 1

/( in.

4 11 4 3

1 This table is based on FHA design recommendations as follows:

(a) When fiber stress is the controlling factor, the assumed total design load is 50 Ib/ft^, composed of 30 Ib/ft^ live load and 20 Ib/ft^ dead load.

(b) When deflection is the controlling factor, i. e., when joists or rafters support a finished ceiling, the deflection limitation of 1/360 of the span

is based on an assumed total load of 30 lb/ft*.

(c) All loads are considered to be acting vertically.

(d) Span is the horizontal projection of the rafter between supports.

> Maximum spans for fiber stresses which are between those tabulated shall be determined by interpolation.

[60]
/or slopes of 3 in 12 and less, supporting plastered ceiling

live load is 20 Ib/lV]

Span ' determined by bending when fiber stress in pounds per square inch is—Continued

700 800 900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

'I

in. ft6

in. ft in. /« in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 5 11 7 4 7 8 8 1 8 5 8 9 9 1 9 5 9 9 10 1 10 4

5 7 6 0 6 4 6 8 7 0 7 4 7 7 7 11 8 2 8 5 8 8 8 11 4 7 4 10 5 2 5 5 5 9 6 0 6 3 6 5 6 8 6 11 7 1 7 4

10 0 10 8 11 4 11 11 12 6 13 1 13 8 14 2 14 8 15 1 15 7 16 0- 8 8 9 3 9 10 10 4 10 10 11 4 11 10 12 3 12 8 13 1 13 6 13 11 7 1 7 7 8 0 8 5 8 10 9 3 9 8 10 0 10 4 10 8 11 0 11 4

13 4 14 3 15 1 15 11 16 9 17 5 18 2 18 10 19 6 20 2 20 9 21 5

11 7 12 4 13 1 13 10 14 6 16 1 15 9 16 4 16 11 17 5 18 0 18 6 9 5 10 1 10 8 11 3 11 10 12 4 12 10 13 4 13 10 14 3 14 8 15 ]

16 11 18 1 19 2 20 2 21 2 22 1 23 0 23 11 24 9 25 6 26 4 27 1 14 7 15 8 16 7 17 6 18 4 19 2 19 11 20 8 21 5 22 1 22 9 23 5

11 11 12 9 13 6 14 3 15 0 15 8 16 3 16 11 17 6 18 1 18 7 19 2:

for slopes of S in 12 and less, supporting plastered ceiling

live load is 30 Ib/fts]

Span 2 determined by bending when fiber stress in pounds per square inch is—Continued

700 800 900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 5 9 6 2 6 7 6 11 7 3 7 7 7 10 8 2 8 6 8 9 9 0 9 3 6 0 5 4 5 8 6 0 6 3 6 7 6 10 7 1 7 4 7 7 7 10 8 0

4 1 4 4 4 8 4 10 5 2 5 4 5 7 5 9 6 0 6 2 6 4 6 7

9 0 9 7 10 2 10 8 11 3 11 9 12 2 12 8 13 1 13 6 13 11 14 4 7 9 8 3 8 9 9 3 9 9 10 2 10 7 11 0 11 4 11 9 12 1 12 5 6 4 6 9 7 2 7 7 7 11 8 3 8 8 8 11 9 3 9 7 9 10 10 2

11 11 12 9 13 6 14 3 14 11 15 8 16 3 16 11 17 6 18 0 18 7 19 2

10 4 11 1 11 9 12 4 13 a 13 6 14 1 14 8 15 2 15 8 16 2 16 7 8 6 9 0 9 7 10 1 10 7 11 1 11 6 11 11 12 4 12 9 13 2 13 6

15 1 16 2 17 1 18 0 18 11 19 10 20 7 21 4 22 1 22 10 23 6 24 2 13 1 14 0 14 10 15 8 16 5 17 1 17 10 18 6 19 2 19 10 20 5 21 0

10 8 11 5 12 1 12 9 13 5 14 0 14 7 15 1 15 8 16 2 16 8 17 2

[61]
Table 10.

Maximum spans ^ for roof rafters for slopes

[For localities where maximum

Size (nominal) Spacing

Span 3 determined by bending when working stress in pounds per square inch is

200 300 400 500 600 700 800

tn. 2X4

2X6

2X8

2X10—.

m

12.. ._ 16 —

24 -

(12 he

l24

(12 - ]l6

l24

(12--- 16

124

ft in. 4 1

ft in. 5 0

10 10

9 5

ft in. 5 10

ft in. 6 6

5 8

4 7

ft in. 7 1

15 3 13 4

10 10

17 1 14 10

12 1

14 9

12 11 10 5

18 8

16 3 13 3

ft in. 7 9

16 0

13 11

20

17

14

ft in. 8 3

7 2

5 10

12 9

11 1

17 0

14 10

12 1

21 8

18 9

15 3

1 This table is based upon FHA design recommendations as follows:

(a) Total load =28 Ib/ft^ acting vertically.

(b) Span is the horizontal projection of the rafter between supports.

2 Weight of roofing material and roof construction = 7 Ib/ft*.

3 Maximum spans for working stresses which are between those tabulated shall be determined by interpolation. Table 10a.

Maximum, spans ' for roof rafters for slopes

[For localities where maximum

Size (nominal) Spacing

in. 12....

1624

1216

,24 -..

fl2-

]l6

l24

(12 ilG

24

Span 3 determined by bending when fiber stress in pounds per square inch is200

ft in. 3 9

3 3

2 8

9 10

8 7 6 11

300

ft in. 4 7

400

ft in. 5 4

4 7

3 9

8 2

7 1 5 10

10 11 9 6

13 10

12 1 9 10

500

ft in. 5 11

15 6

13 5 10 11

600

ft in. 6 6

5 8

700

ft in.

10 10

9 5

1412

10

1 This table is based upon FHA design recommendations as follows:

(a) Total load=34 lb/ft2 acting vertically.

(b) Span is the horizontal projection of the rafter between supports.

2 Weight of roofing material and roof construction = 7 Ib/ft'.

3 Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

[62]
between Syi in 12 and S in 12, light roofing material ^

. five load is 20 Xbim

Span 3 determined by bending when working stress in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft8

in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 9 9 3 9 8 10 1 10 6 10 11 11 4 11 8 12 0 12 4

7 7 8 0 8 5 8 9 9 1 9 6 9 10 10 1 10 5 10 9

6 2 6 6 6 10 7 1 7 5 7 9 8 0 8 3 8 6 8 9

13 6 14 3 15 0 15 7 16 3 16 11 17 6 18 0 18 7 19 2

11 9 12 5 13 0 13 7 14 1 14 9 15 2 15 9 16 2 16 8

9 7 10 1 10 7 U 1 U 6 12 0 12 4 12 10 13 2 13 6

18 1 19 1 20 0 20 U 21 10 22 6 23 4 24 1 24 10 25 7 IS 9 16 7 17 5 18 2 18 11 19 8 20 4 21 0 21 8 22 3 12 10 13 6 14 2 14 10 15 5 15 11 16 6 17 1 17 7 18 2

22 11 24 2 25 4 26 5 27 6 28 7 29 6 30 6 31 5 32 5 19 11 21 0 22 0 23 0 24 0 24 11 25 8 26 6 27 4 28 3

16 3 17 1 17 11 18 9 19 6 20 3 20 11 21 7 22 3 22 H

hetween 10}i in 12 and 3 in 12, light roofing material

Uve load is 30 Ib/ft^]

Span 3 determined by bending when fiber stress in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

in. ft8

in. ft8

in. ft9in. ft in. ft in. ft in. ft in. ft in. ft in. 11 4 9 2 9 6 9 11 10 3 10 7 10 11 11 2

6 11 7 3 7 7 8 0 8 4 8 7 8 11 9 2 9 6 9 9

5 7 5 11 6 2 6 6 6 9 7 0 7 3 7 6 7 9 7 11

12 4 13 0 13 7 14 2 14 10 15 4 15 11 16 5 16 11 17 5

10 8 11 3 U 10 12 4 12 10 13 4 13 10 14 3 14 9 15 1

8 8 9 2 9 7 10 0 10 6 10 10 11 3 11 7 12 0 12 4

16 5 17 4 18 2 18 11 19 9 20 6 21 3 21 11 22 7 23 3

14 3 15 1 15 9 16 6 17 2 17 10 18 5 19 0 19 7 20 3

11 7 12 3 12 10 13 5 13 11 14 6 15 0 15 6 15 11 16 5

20 10 21 11 22 11 24 0 25 0 25 11 26 10 27 9 28 6 29 5 18 1 19 1 20 0 20 10 21 9 22 6 23 4 24 1 24 10 25 6

14 9 16 6 16 3 17 0 17 9 18 4 18 11 19 7 20 3 20 10

[63]
Table 11.

Maximum spans ' for roof rafters for slopes

[For localities where maximmn

Spacing

(12 ]l6

12. 16

24

(12 ]l6

(12

I24

Span 3 determined by bending when working stress * in pounds per square inch is200

ft in.

5

4

3

76

5

109

7

13

11

300

/( in.

12 10

11 2

16

14

11

400

ft in.

7 1 6 2

5 0

14 9 12 11

1816

13

500

ft in.

8 11 6 11

600

ft in.

8 9

7 7

18 1 15 9 12 10

22 11 19 11 16 3

700

ft in.

9 5

8 3

1412

10

19

17

70

13 10

24

21

17

800

ft in.

10 1 8 9

7 1

15

13

11

20 11 18 2

14 10

26

23

18

1 This table is based upon FHA design recommendations as follows:

(a) Total load=28 Ib/ft^ acting normal to the roof.

(b) Span is the sloping length of rafter between supports.

2 Weight of roofing material and roof construction =7 lb/ft 3. 3 Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

* The tabulated spans are based upon fiber stresses which are 50% greater than the working stresses shown at the head of each column. See sec. 709-3, Table 11a.

Maximum spans ' for roof rafters for slopes

[For localities where maximum

Size (nominal) Spacing

Span 3 determined by bending when working stress* in pounds per square inch is—

200 300 400 500 600 700 800

in. in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 12_.___ 5 0 6 2 7 1 8 11 8 9 9 5 10 1 2X4 16...-. 4 5 6 4 6 2 6 U

8

7 7 8 3 8 9

l24_-... 3 7 4 4 5 0 5 6 2 6 8 7 1

(12..... 7 10 9 7 11 0 12 4 13 6 14 7 15 7 2X6 16..... 6 10 8 4 9 7 10

8

9 11 9 12 9 13 7

124 5 7 6 9 7 10 9 9 7 10 4 11 1

(12..... 10 5 12 10 14 9 16 0 18 1 19 7 20 11 2X8 ]l6_._._ 9 1 11 2 12 11 14 5 15 9 17 0 18 2

[24 7 4 9 1 10 5 11 8 12 10 13 10 14 10

(12..... 13 3 16 2 18 8 20 11 22 11 24 9 26 5 2X10 im 11 6 14 2 16 3 18 2 19 11 21 6 23 0

[24 9 4 11 5 13 3 14 10 16 3 17 6 18 9

1 This table is based upon FHA design recommendations as follows:

(a) Total load=28 Ib/ft^ acting normal to the roof.

(b) Span is the sloping length of the rafter between supports.

3 Weight of roofing material and roof construction =7 lb/ft'.

» Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

* The tabulated spans are based upon fiber stresses which are 50% greater than the working stresses shown at the head of each column. See sec. 709-3.

[64]
of 8Y2 in 12 and greater, light roofing material *

live load is 20 lb/ft >]

Span 3 determined by bending when working stress < in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in.

10 8 11 4 11 10 12 4 12 10 13 4 13 10 14 3 14 8 15 1 9 4 9 10 10 4 10 9 11 2 11 7 12 0 12 5 12 9 13 2

7 7 8 0 8 4 8 9 9 1 9 5 9 9 10 1 10 5 10 8

16 7 17 6 18 4 19 2 19 11 20 8 21 5 22 2 22 11 23 6

14 5 15 2 16 0 16 8 17 5 18 0 18 8 19 3 19 10 20 5

11 9 12 4 12 11 13 6 14 1 14 8 15 2 15 8 16 2 16 7

22 2 23 4 24 6 25 7 26 7 27 7 28 7 29 6 30 5 31 4 19 4 20 4 21 4 22 3 23 2 24 0 24 11 25 9 26 6 27 4 15 8 16 6 17 4 18 2 18 10 19 7 20 2 20 11 21 7 22 2

28 0 29 6 31 1 32 5 33 10 35 0 36 3 37 6 38 8 39 10 24 5 25 8 27 0 28 3 29 4 30 5 31 7 32 7 33 7 34 6

19 10 20 11 22 0 22 11 23 11 24 10 25 8 26 6 27 3 28 1

of lOYi in 12 and greater, light roofing material ^

live load is 30 Ib/ft^]

Span 3 determined by bending when working stress* in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 10 8 11 4 11 10 12 4 12 10 13 4 13 ]0 14 3 14 8 16 1 9 4 9 10 10 4 10 9 11 2 11 7 12 0 12 5 12 9 13 2 7 7 8 0 8 4 8 9 9 1 9 5 9 9 10 1 10 5 10 8

16 7 17 6 18 4 19 2 19 11 20 8 21 5 22 2 22 11 23 6

14 5 15 2 16 0 16 8 17 5 18 0 18 8 19 3 19 10 20 5 11 9 12 4 12 11 13 6 14 1 14 8 15 2 15 8 16 2 16 7

22 2 23 4 24 6 25 7 26 7 27 7 28 7 29 6 30 5 31 4

19 4 20 4 21 4 22 3 23 2 24 0 24 11 25 9 26 6 27 4 15 8 16 6 17 4 18 2 18 10 19 7 20 2 20 11 21 7 22 2

28 0 29 6 31 1 32 5 33 10 35 0 36 3 37 6 38 8 39 10 24 5 25 8 27 0 28 3 29 4 30 5 31 7 32 7 33 7 34 6 19 10 20 11 22 0 22 11 23 11 24 10 25 8 26 6 27 3 28 1

[65]
Table 12.

Maximum spans ' for roof rafters for slopes

[For localities where maximum

Spacing

m.

12

16

,24_.

12

16

24_ _

12__ 16

.24

(12- 16- — -.

[24

Span 3 determined by bending when working stress in pounds per square inch is—

200 300 400 500 600 700 800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. 3 9 4 7 5 4 5 11 6 6 7 0 7 6

3 3 4 0 4 7 5 1 5 8 6 1 6 6

2 8 3 3 3 9 4 2 4 7 4 11 5 3

5 10 7 1 8 2 9 2 10 0 10 10 11 7

5 0 R 2 7 1 7 11 8 8 9 5 10 0

4 1 5 0 5 10 6 6 1 7 8 8 2

7 9 9 5 10 11 12 3 13 5 14 6 15 6

6 9 8 3 9 6 10 7 11 8 12 8 13 6

S 5 6 9 7 9 8 8 9 5 10 3 10 11

9 10 12 0 13 10 15 6 17 0 18 4 19 7 8 7 10 5 12 1 13 5 14 9 16 0 17 1 6 11 8 6 9 10 10 11 12 0 13 0 13 10

1 This table is based upon FHA design recommendations as follows:

(a) Total load=34 Ib/ft^ acting vertically.

(b) Span is the horizontal projection of the rafter between supports.

2 Weight of roofing material and roof construction =12.5 Ib/ft^.

' Maximum spans for working stresses which are between those tabulated shall be determined by interpolation. Table 12a.

Maximum spans ' for roof rafters for slopes

[For localities where maximum

Size Span 3 determined by bending when working stress in pounds per square inch is

(nominal) Spacing

200 300 400 500 600 700 800

in. 112

in. ft

3

in.5

ft4

in.3

ft4

in. 11

ft5

in.5

ft6

in.0

ft6

in.5

ft6

in. 11 2X4— 16- 3 0

6

3 8 4 3 4 9 5 2 5 7 6 0

[24 - 2 3 0 3 5 3 11

6

4 3 4 7 4 11

(12 5 4 6 7 7 7 8 9 3 10 8

8 08

10 2X6 ]l6 - 4 8 5 8 6 7 7 4 8 1 9 4

124 - 3 10 4 8 5 4 6 0 6 7 7 1 7 7

(12 7 2 8 9 10

8

1 11 3 12 4 13 4 14 3 2X8 16 6 3 7 8 9 9 10 10

8 9 119

7 12 5 l24.- 5 1 6 2 7 2 8 0 9 5 10 1

(12 - 9 0 119

18

12 9 14 4 15 8 16 11818 1 2X10- 16 7 10 11 1 12 5 13 7 14 15 9

l24 , 6 4 7 10 9 0 10 1 11 1 11 11 12 9

1 This table is based upon FHA design recommendations as follows:

(a) Total load=40 Ib/R- acting vertically.

(b) Span is the horizontal projection of the rafter between supports.

• Weight of roofing material and roof construction = 12.5 lb/ft'.

3 Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

«

[66]
between Syi in 12 and 3 in 12, heavy roofing material ^

live load is 20 lb/ft!]

Span 3 determined by bending when working stress in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

n in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 7 11 8 i 8 9 9 2 9 6 9 11 10 3 10 7 10 11 11 2 6 11 7 3 7 7 8 0 8 4 8 7 8 11 9 2 9 0 9 9

5 7 5 11 C 2 6 6 6 9 7 0 7 3 7 6 7 9 7 11

12 4 13 0 13 7 14 2 14 10 15 4 16 11 16 5 16 11 17 5 10 8 11 3 11 10 12 4 12 10 13 4 13 10 14 3 14 9 15 1 8 8 9 2 9 7 10 0 10 6 10 10 11 3 11 7 12 0 12 4

16 5 17 4 18 2 18 11 19 9 20 6 21 3 21 11 22 7 23 3 14 3 15 1 16 9 16 6 17 2 17 10 18 6 19 0 19 7 20 3

11 7 12 3 12 10 13 6 13 11 14 6 15 0 15 6 16 11 16 5

20 10 21 11 22 11 24 0 25 0 26 11 26 10 27 9 28 6 29 5 18 1 19 1 20 0 20 10 21 9 22 6 23 4 24 1 24 10 25 6

14 9 15 6 16 3 17 0 17 9 18 4 18 11 19 7 20 3 20 10

between in 12 and S in 12, heavy roofing material ^

live load is 30 lb/ft

Span 3 determined by bending when working stress in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 7 4 7 8 8 1 8 5 8 9 9 2 9 5 9 9 10 1 10 4

6 4 6 8 7 0 7 4 7 8 7 11 8 2 8 6 8 9 9 0

6 2 5 6 5 9 6 0 6 3 6 6 6 8 6 11 7 1 7 4

11 4 12 0 12 6 13 1 13 8 14 2 14 8 16 1 15 7 16 0

9 10 10 6 10 11 11 5 11 10 12 4 12 8 13 1 13 6 13 11 8 0 8 6 8 11 9 4 9 8 10 0 10 4 10 8 11 0 11 4

16 2 15 11 16 9 17 6 18 2 18 11 19 7 20 3 20 10 21 5 13 2 13 10 14 7 15 2 15 10 16 6 17 0 17 7 18 1 18 7 10 8 11 3 11 10 12 4 12 11 13 5 13 10 14 3 14 8 15 1

19 3 20 3 21 2 22 1 23 0 23 11 24 9 25 6 26 4 27 1 16 8 17 7 18 5 19 3 20 0 20 9 21 6 22 3 22 10 23 6

13 7 14 4 15 0 15 8 16 3 16 11 17 6 18 1 18 7 19 1

[67]
Table 13.

Maximum spans for roof rafters for slopes

I For localities where maximum

Spacing

12

(12

l24

(12 m

12. 16

24

Span 3 determined by bending when working stress * in pounds per square inch is

200

ft in. 4 7

12

10

300

ft in. 5 7

4 10

3 11

7 6

6 2

11 8

10 1 8 3

14 9 12 9

10 6

400

ft in.

500

ft in. 7 3

6 3

7 11

600

ft in. 7 11 6 11

6 7

12 4

10 8

20 10

18 1

700

ft in. 8 7

7 5 6 0

13 4

11 6

22 6 19 6

15 11

800

ft in. 9 2

18 11 16 6

24 0 20 10

17 0

1 This table is based upon FHA design recommendations as follows:

(a) Total load =34 Ib/ft^ acting normal to the roof. (b) Span is the sloping length of rafter between supports.

3 Weight of roofing material and roof construction = 12. 5 lb/ft'.

5 Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

1 The tabulated spans are based upon fiber stresses which are 50% greater than the working stresses shown at the head of each column. See sec. 709-3. Table 13a.

Maximum spans ' for roof rafters for

[For localities where maximum

Size (nominal) Spacing

Span 3 determined by bending when working stress * in pounds per square inch is

200 300 400 500 600 700 800

in. in. ft in. ft in. ft in. ft in. ft in. ft8in. ft in. 12-._. 4 7 5 7 6 6 7 3 7 11 7 9 2 2X4 ]l6 4 0 4 10 5 8 6 3 6 11 7 6 8 0

l24.__._ 3 3 3 11 4 7 5 1 5 7 6 0 6 6

(12 7 1 8 9 10 0 11 3 12 4 13 4 14 2 2X6 ]l6-_— 6 2 7 6 8 8 9 9 108

8 119

6 12 4

l24._-__ 5 0 6 2 7 1 7 11 8 5 10 0

(12..... 9 5 11 8 13 5 15 0 16 6 17 9 18 11 2X8 ]l6-_.. 8 3 10

8

1 11

9 8 13 0 14 3 15 5 16 6[24...._ 6 9 3 5 10 8 11 7 12 7 13 6

(12 12 0 14 9 17 0 19 0 20 10 22 6 24 0 2X10 10 5 12 9 14 9 16 6 18 1 19 6 20 10

l24 8 6 10 5 12 0 13 6 14 9 15 11 17 0

1 This table is based upon FHA design recommendations as follows:

(a) Total load =34 Ib/ft^ acting normal to the roof.

(b) Span is the sloping length of rafter between supports.

2 Weight of roofing material and roof construction = 12.5 Ib/ft^.

3 Maximum spans for working stresses which are between those tabulated shall be determined by interpolation.

* The tabulated spans are based upon fiber stresses which are 50% greater than the working stresses shown at the head of each column. See sec

709-3.

[68]
of SVi in 12 and greater, heavy roofing material ^

live load is 20 Ib/fta]

Span 3 determined by bending when working stress* in pounds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

n in. It in. ft in. /( in. ft in. ft in. ft in. ft in. ft in. ft in. 9 9 10 3 10 9 11 2 11 8 12 1 12 6 12 11 13 4 13 9

8 5 8 11 9 4 9 9 10 1 10 6 10 11 11 3 11 7 11 11 6 10 7 3 7 7 7 11 8 3 8 7 8 10 9 2 9 5 9 9

15 1 15 11 16 8 17 5 18 2 18 9 19 6 20 1 20 9 21 4 13 1 13 10 14 6 15 1 15 9 16 4 16 11 17 6 18 0 18 6

10 8 11 3 11 9 12 4 12 10 13 4 13 9 14 3 14 8 15 1

20 1 21 3 22 3 23 3 24 2 25 0 26 0 26 10 27 9 28 5 17 6 18 5 19 4 20 3 21 0 21 10 22 7 23 4 24 0 24 9

14 3 15 0 15 9 16 5 17 1 17 9 18 4 19 0 19 7 20 1

25 5 26 10 28 2 29 5 30 7 31 9 32 11 34 0 35 0 36 0

22 1 23 4 24 6 25 6 26 7 27 8 28 7 29 7 30 6 31 4

18 0 18 11 19 11 20 10 21 9 22 5 23 3 24 0 24 10 25 6

slopes of lOy^ in 12 and greater, heavy roofing material '

live load is 30 lb/ft2]

Span s determined by bending when working stress < in poimds per square inch is—Continued

900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800

ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. ft in. 9 9 10 3 10 9 11 2 11 8 12 1 12 6 12 11 13 4 13 9

8 5 8 11 9 4 9 9 10 1 10 6 10 11 11 3 11 7 11 11 6 10 7 3 7 7 7 11 8 3 8 7 8 10 9 2 9 5 9 9

15 1 15 11 16 8 17 5 18 2 18 9 19 6 20 1 20 9 21 4

13 1 13 10 14 6 15 1 15 9 16 4 16 11 17 6 18 0 18 6

10 8 11 3 11 9 12 4 12 10 13 4 13 9 14 3 14 8 15 1

20 1 21 3 22 3 23 3 24 2 25 0 26 0 26 10 27 9 28 5 17 6 18 5 19 4 20 3 21 0 21 10 22 7 23 4 24 0 24 9

14 3 15 0 15 9 16 5 17 1 17 9 18 4 19 0 19 7 20 1

25 5 26 10 28 2 29 5 30 7 31 9 32 11 34 0 35 0 36 0

22 1 23 4 24 6 25 6 26 7 27 8 28 7 29 7 30 6 31 4 18 0 18 11 19 11 20 10 21 9 22 5 23 3 24 0 24 10 25 6

[69]
Paragraph 709-6 (a). Load-Carrying Capacity

Walls constructed with 2- by 4-inch studs of average

quality, spaced 16 inches on centers and well tied and

braced, constitute one form of construction that will meet the load requiredments of this Code. For one- story buildings a stud spacing of 2 feet is adequate.

Paragraph 709-6 (d). Stucco on Wood-Frame

Construction

In back-plastered construction, the base for the stucco

is attached directly to tlie studs. Adequate bracing is necessary with this type of construction.

Paragraph 709-6 (h). Framing over Openings in

Bearing Walls

The requirements of Section 709-6 (h) regarding

lintels will be met by the use of the following formula: Span = nominal height in inches X

VT ^ 50 ^ given stress 16 given load 1,200 given joist span

'

in which

7^= total actual thickness of members

comprising lintel; Given load = total load per square foot of floor area. For lintels over openings in bearing partitions, the span of the joists shall be taken as the sum of the spans on the two sides of the partition. Care must be exercised to see that the safe horizontal- shear stress is not exceeded. This is likely to occur whenever the product of the quantities under the radical

is less than 1. The nailing at the ends of lintels may be the same as

for headers; but a better construction for heavy vertical loads is to double the studs from the support to the underside of the lintel and, in addition, to nail each end of each lintel member with two twentypenny nails if 2- by

4-inch material is used and with at least three twentypenny nails if 2- by 6-inch material or larger is used.

Paragraph 709-8 (b). Headers and Trimmers

Not more than five tail beams should be framed to a header when the trimmers are of the same size as the

joists which are of the minimum size and strength per- mitted by the Code. Six tail beams are permitted when

the joists and trimmers are of the next standard height

greater or if the trimmers are 25 percent stronger than is required for the joists. Not more than two tail beams should be framed to the header on each side of the opening when the trim- mers are of the same size as the joists which are of the minimum size and strength permitted by the Code.

Three tail beams are permitted on each side of the opening if the joists are of the next standard height

greater or if the trimmers are 25 percent stronger than

are required for the joists. Four tail beams are per- mitted if the trimmers are both higher and stronger, as given above.

Framing around openings larger than above or details not covered should be designed by a competent engineer.

The tail beams of 2-inch thickness in ordinary dwellings, when 6 inches or more in height and supported by

nails, should have not less than three twentypenny

nails through the first header into each tail beam nor

less than one twentypenny nail for each 4 square feet of

floor supported by the tail beam. The second header

should be nailed through the first header into the tail beam by not less than two-thirds as many twentypenny

nails as were required in nailing the first header to the

tail beams.

The headers should be nailed to the first trimmer by

not less than three twentypenny nails through the first trimmer into each end of each header. The total number of nails into each end of the header, through the

first trimmer, should be not less than one for each 8 square feet of floor supported by the tail beams. The

second trimmer should be nailed through the first trim- mer and into the headers with not less than two-thirds

as many nails as are required for the first trimmer to the header. Toe nailing or other means of support may be substi- tuted for the direct nailing given above provided it has

at least the strength and rigidity offered by the required

nailing given above.

Paragraph 709-8 (c). Collar Beams and Tie Beams

The minimum size of collar beams should be 1 inch by 6 inches or 2 by 4 inches, with maximum spacing of 5 feet. When ceiling joists do not serve as a tie at the

plate line, ceiling joists or other ties on each pair of rafters are necessary somewhere below the upper third and they should be well spiked to each rafter. Special

provision for tying the lower ends of the rafters to the

floor or wall construction should also be made.

Paragraph 709-8 (d). Bridging

A line of bridging should be provided at all supports

where adequate stiffening is not otherwise provided.

Paragraph 709-9. Plank-and-Beam Construction

In addition to the specific requirements of Section

709-9, the following procedure should be observed: When beams are built of two or more laminations,

all laminations should be securely spiked together from

both outside faces. The ends of each lamination should bear on a support. When beam laminations

are spaced to allow passage of utilities or for other

reasons, they should be blocked at frequent intervals at each space between laminations and each lamination should be securely nailed to the blocking.

To avoid undue contraction after laying, plank should be protected from the elements during storage and construction. Finish flooring, when used, should be not less than

inch thick and should be laid at right angles with

the plank of the subfloor over building paper or felt.

[70]
In two-story plank-and-beam construction, the studs

at the second floor should be cut and capped with a

plate to provide bearing for second-floor beams. Solid blocking or fillers whose depth is equal to that of the

second-floor beam should be provided between beams

and members of spaced beams at the exterior wall. The

studs should bear on a plate laid on the plank flooring

which extends to the outside wall. Solid or built-up posts supporting beams should be squared at both ends to provide full bearing.

Plank-and-beam construction may be used for the

first floor in conjunction with conventionally framed

second floors, roofs, or ceilings. Where conventional joist framing is used above the first floor, the requirements

already set forth for framed construction should apply.

When joisted construction is used in the second floor in conjunction with plank-and-beam construction in the

first floor, bearing partitions should be placed directly over beams whose section has been increased sufficiently to carry the additional load, or special framing, either within the bearing partition or in the supporting floor system, should be provided to carry the additional load. Interior columns should be designed to support

adequatel}' their loads, and the column ends should be

squared to provide uniform bearing for the beams.

Provision should be made for adequate bearing under

beams by suitable column dimensions, suitable corbels

or caps, by notching the columns, or by spiking bearing

blocks not less than 2 feet long to the sides of the column.

Paragraph 709-10 (a). Material

Commercial Standard CS45-40 "Douglas Fir Plywood (Domestic Grades)" is obtainable from the Superintendent of Documents, Washington, D. C, for

5 cents.

Paragraph 709-10 (b). Gluing Plywood to Framing

Members

Navy Department Specification 52G8b, July 1, 1932,

"Glue, Casein, Water-Resistant" is obtainable from the Bureau of Supplies and Accounts, Navy Department,

Washington, D. C. Navy Aeronautical Specification G-29, April 4, 1941,

''Glue, Cold Setting Resin" is obtainable from the Naval Aircraft Factory, U. S. Navy Yard, Philadelphia,

Pa.

Paragraph 709-10 (c). Design of Flat Panel With

Stressed Coverings

The safe stress and methods of calculating the stress

in a flat panel with stressed covering as given below

apply only to panels with plywood covering glued to longitudinal wood members.

(1) Construction features.—The gluing between the frame and plywood covers and also between plywood

laminations should be good.^^

25 It is essential to have good gluing between the frame and the covering, and it is almost equally important to have good bond and strength within

the covering.

The longitudinal members should be at least twice

as thick (cross-sectional dimension next to the covering) as the thicker covering.

Headers must be provided with longitudinal members

whose ratio of height to thickness is 2 or more.

(2) Strength and stiffness.—In calculating the strength

and stiffness of a plywood panel, any clear width of covering in excess of b between any two longitudinal

members should be neglected. Panels with a clear dis- tance between longitudinal members over 2b should not

be considered as having stressed covering. The value

of b shall be determined by the following formulas: For three plies:

b = Z\hJ ^ V parallel plies thickness For five or more plies:

b=S6h^/ ^ V parallel plies thickness where ?; = basic width between longitudinal members

(clear distance, not center to center)

;

/i'= thickness of plywood cover. With b determined for plywood as above, the strength

and stiffness of the panel should be determined from

the strength values for clear wood given in table 1. First calculate the moment of inertia of the section,

neglecting the cross plies and all covering in excess of b. Then calculate the stiffness, using the modulus of elasticity for the species taken from table 1. In calculating the safe strength for spacing of longitudinal members

one-half b or less, use for high-grade plywood on the compressive face 85 percent, and for a medium grade

of plywood 75 percent, of the basic stress in compression parallel to the grain, increased when used in a

continuously dry location by 25 percent.

When the clear distance between the longitudinal

members is greater than one-half b, reduce the stress uniformly from that allowed at one-half b to twothirds this amount at a spacing of b. In calculating the strength on the tension face, use

the basic stress in extreme fiber in bending (table 1) and proceed as above.

Paragraph 709-11. Termites and Decay

For suggestions on suitable provisions for ventilation beneath buildings, the committee is indebted to the Bureau of Entomology and Plant Quarantine, United

States Department of Agriculture. Additional information will be found in Prevention and Control of Decay in Dwellings, Technical Note No. 251, issued by the Division

of Forest Pathology of the United States Department of Agriculture and obtainable without charge from the

Forest Products Laboratory, Madison, Wis. For further information on methods of guarding

against termites, see Insects in Relation to National

Defense, Circular 2, and Supplement A thereto, issued

in February and June 1941 by the Bureau of Entomology and Plant Quarantine of the United States Department of Agriculture.

[71]
The more decay-resistant species mentioned in Section 709-11 (h) include baldcypress, redwood, and

cedar. Paragraph 800. General

The specifications referred to in Section 800 are ob- tainable from the American Society for Testing Materials, 260 South Broad Street, Philadelphia, Pa., for 25 cents. Paragraph 801. Fire Separation

In Section 801 and elsewhere in the Code, certain

fire-resistance requirements for walls or partitions sep- arating dwellings or dwelhng units are given. For

specific materials and thicknesses which will meet

these requirements, reference should be made to publi- cations on the subject, which include the following:

BH14, Recommended Minimum Requirements for Fire Resistance in Buildings;

BMS71, Fire Tests of Wood- and Metal-Framed

Partitions

BMS92, Fire Resistance Classifications of Building

Constructions. The first two publications are issued by the National Bureau of Standards and are obtainable from the Su- perintendent of Documents, Washington, D. C, for 10 and 20 cents, respectively. The third publication is obtainable direct from the National Bureau of Standards,

Washington, D. C. Additional information on fire resistance of various structural members is being devel- oped through research at the National Bureau of Standards. Inquiries concerning this should be addressed to the Bureau at Washington, D. C.

It is recommended that draft stops be placed in attic spaces whenever walls or partitions are not carried up

to the under side of the roof sheathing. Such draft stops should be placed at least at every second dwelling

and should have incombustible material on at least one side. As a basis for determining whether an attic can be

used for storage, it is suggested that an opening con- taining more than 400 square inches should be consid- ered as making storage possible.

Paragraph 802-1. General

It is desirable that firestopping in partitions between

dwelling units should be incombustible.

Paragraph 804. Roof Coverings

Through the courtesy of the Subcommittee on Fire Resistance Classifications of the Central Housing Committee on Research, Design, and Construction, the

following information has been supplied concerning

roof coverings:

Lists of Acceptable Roof Coverings

The general requirements of Section 804 are exemplified by the following lists of roof coverings of which a

sufficient number have been tested to indicate acceptability for the different classifications. Pending the establishment of definite performance requirements for various classes of roof coverings, additional coverings not included herein can be classified by comparison

under recognized tests with roof coverings hereafter

classified. Built-up Roof Coverings.^^ Built-up roof coverings are assumed to be applied according to accepted good practice. The minimum total combined weight of bonding

and coating materials required per 100 sq ft of roof

surface, for coverings nailed to deck and coverings held

in place by cementing material applied directly to deck,

are given below. In the case of roof coverings nailed

to deck, weights are based on designs which permit the

least number of felt layers to be bonded with cementing

material. Weights of felt given below are minima.

Roofs surfaced with gravel or slag require not less than 400 lb of roofing gravel or crushed stone or 300 lb

of crushed slag per 100 sq ft of roof surface.

Class 1 . Built-up roof coverings

Kinds of built-up roof coverings

Asbestos-felt saturated with asphalt, bonded

and surfaced with asphalt cement:

(1) 4 layers of 14-lb felt (18-Ib if coated)___

(2) 2 layers of 28-lb felt (each of 2-ply 14-lb

felt) (3) 1 layer of 35-lb felt (55-lb if coated) and

2 layers of 14-lb felt (18-lb if coated) . _. (4) 3 layers of 14-lb felt (18-lb if coated). Limited to incombustible decks __ . (5) 2 layers of 35-lb felt (55-lb if coated). Limited to incombustible decks

Rag-felt saturated with asphalt, bonded with

asphalt cement and surfaced with gravel or

slag on asphalt cement:

(1) 4 layers of 14-lb felt .• (2) 1 layer of 28-lb felt and 2 layers of 14-lb

felt--

(3) 1 layer of 14-lb felt and 2 layers of 20-lb or heavier cap or base sheets

(4) 3 layers of 20-lb or heavier cap or base

sheets

(5) 3 layers of 14-lb felt. Limited to in- combustible decks

Asbestos-felt satiu:ated with asphalt and ragfelt saturated with asphalt bonded and sur- faced with asphalt cement:

(1) 1 layer of 28-lb rag-felt and 2 layers of

14-lb asbestos felt (18-lb if coated). Limited to incombustible decks

Asbestos-felt or rag-felt saturated with tar, bonded with tar and surfaced with gravel or

slag on tar:

(1) 4 layers of 14-lb felt (2) 3 layers of 14-lb felt. Limited to in- combustible decks -

Rag-felt saturated with asphalt, bonded with

asphalt cement and surfaced with H-in. as- phalt impregnated fibrous board applied with asphalt mastic:

(1) 3 layers of 14-lb felt or other class built- up roofing

Minimum weight of cementing material per 100 sq ft

Nailed to deck Cemented

to deck

lb lb

60 110

40 70

60 90

40 90

40 70

100 150

100 130

100 130

100 130

80 130

60 90

120 185

95 160

40 90

2« Built-up roof coverings are those which are composed of materials which are bonded together into layers as they are put in place on the

roof.

[72]
Class 2. Built-up roof coverings thickness of the roof covering is not a consideration as

far as fire resistance is concerned.

Kinds of built-up roof coverings

Asbestos-felt saturated with asphalt, bonded

and surfaced with asphalt cement:

(1) 3 layers of 14-lb felt (18-lb if coated) . . .

.

(2) 2 layers of 35-lb felt (55-lb it coated)

(3) 1 layer of 35-lb felt (55-lb if coated) and

1 layer of 14-lb felt (18-lb if coated) _ _

.

Eag-felt saturated with asphalt, bonded with

asphalt cement and surfaced with gravel or

slag on asphalt cement:

(1) 3 layers of 14-lb felt

(2) 2 layers of 30-lb or heavier cap or base

sheets

Asbestos-felt or rag-felt saturated with tar, bonded with tar and surfaced with gravel or

slag on tar:

(1) 3 layers of 14-lb felt ,

Minimum weight of cementing material per 100 sq ft

Nailed to deck

40

80

96

Cemented

to deck

70

70

130

110

160

Class 3. Built-up roof coverings

Minimum weight of cementing material per 100 sq ft Kinds of built-up roof coverings

Nailed to Cemented

deck to deck

lb lb Eag-felt saturated with asphalt, bonded and

surfaced with asphalt cement:

(1) 3 layers of 14-lb felt 40 90

(2) 1 layer of 28-lb felt and 1 layer of 14-lb

felt 40 70

(3) 2 layers of 20-lb or heavier cap or base

sheets _ __ 40 70

(4) 2 layers of 14-lb felt and 1 layer 14-lb or heavier cap or base sheet . .

.

40 90

Prepared Roof Coverings.^'' Prepared roof coverings are assumed to be applied according to accepted good

practice. Where rag felt is indicated, asbestos felt of equal weight can be substituted. From the standpoint of relative efifectiveness of the

different types of wood roof sheathing, the tongue-andgroove boards gave the best results in the brand and

flame tests and the square-edge sheathing with boards

spaced about }4 inch apart were indicated as better than slat decks of 3-inch strips spaced 5 or more inches on centers. Accordingly for classifications based on

slat-supporting construction, square-edge or tongueand-groove sheathing can be substituted and the latter can be substituted for the square-edge sheathing.

By "end lap" is meant the overlapping length of two

units, one placed over the other. Head lap is the dis- tance that the lower of three superimposed units overlaps the upper unit. Where the coverings are applied over concrete or other masonry roof slabs of 1 inch or greater thickness, the

" Roof coverings which have been preassembled or formed into final shape before being installed are known as prepared roof coverings.

Class 1. Prepared roof coverings

Brick 2% inch thick. Metal-reinforced portland cement concrete 1 inch

thick. Concrete tile or clay floor tile or deck tile 1 inch thick. Flat or French type clay or concrete roof tile, % inch thick with lJ4-inch or more end lap and head

lock spacing body of tile Yi inch or more above roof sheathing, with underlay of asphalt-saturated rag-felt

in one or two layers of total weight not less than 24 lb per 100 sq ft or one layer of asphalt-saturated asbestosfelt weighing not less than 14 lb per 100 sq ft. Clay or concrete roof tile, Spanish or Mission pattern,

%6 inch thick, 3-inch end lap, same underlay as above.

Slate %6 inch thick, 3-inch head lap.

Cement-asbestos shingles laid American method, %6-

inch or greater average thickness, 2-inch head lap.

Asphalt-saturated asbestos sheet roofing, 4-ply with an unsaturated asbestos top sheet, weight not less than

80 lb per 100 sq ft of roof surface, laid in single thickness with 2-inch end lap and side edges butted, with 6-inch wide strip beneath.

Class 2. Prepared roof coverings

Cement-asbestos shingles of Ke-inch or greater thickness laid with not less than 2-inch side, end, or combined side and end lap, according to the French,

Dutch, or Scotch method, with underlay of asphalt- saturated rag-felt in one or two layers of total weight

not less than 24 lb per 100 sq ft or one layer of asphalt- saturated asbestos-felt weighing not less than 14 lb per 100 sq ft. Asphalt-asbestos smooth-surfaced sheet roofing 3-ply

laid in single thickness, weight not less than 60 lb per

100 sq ft of roof surface with 2-inch end lap and side edges butted, with 6-inch wide strip beneath.

Asphalt-asbestos felt smooth-surfaced sheet roofing,

3-ply with an unsaturated asbestos top sheet, weight not

less than 55 lb per 100 sq ft of roof surface laid in single thickness with 2-inch or more end and side laps. Asphalt-asbestos felt shingles made of asbestos felt saturated and coated with asphalt, surfaced with mineral granules and weighing not less than 80 lb per 108

sq ft and as laid on the roof with 2-inch or more head

lap, not less than 180 lb per 100 sq ft of roof surface. Asphalt mastic shingles composed of asphalt and

fibrous and granular materials of which not less than 45

percent by weight is incombustible, laid with not less than 2-inch head lap, total weight not less than 425

lb per 100 sq ft of roof surface. Copper, galvanized-iron, or tin-coated iron standing- seam or flat-seam sheet roofings, underlaid with 14- pound saturated or unsaturated asbestos felt or asphalt- saturated rag-felt in one or two layers of total weight

not less than 24 lb per 100 sq ft. Copper or galvanized-iron tile or shingle pattern

roofings with same underlay as above.

73
Class 3. Prepared roof coverings

Copper, galvanized-iron, or tin-coated standing-seam

or flat-seam sheet roofing either without underlay or with underlay of rosin-sized paper. Copper or galvanized-iron tile or shingle pattern roof- ings without underlay or with underlay of rosin-sized paper. Asphalt rag-felt individual or strip shingles made of

rag-felt saturated and coated with asphalt, surfaced with mineral granules and weighing not less than 80

lb per 108 sq ft and as laid on the roof with 2-inch or more head lap, not less than 180 lb per 100 sq ft of roof

surface. Asphalt-asbestos felt roll roofing surfaced with mineral granules and laid in single thickness with 2-inch or more side and end laps, weight not less than 85 lb per 100 sq ft of roof surface. Asphalt-asbestos felt smooth-surfaced sheet or roll roofing laid in single thickness with 2-inch or more end

and side lap, weight not less than 50 lb per 100 sq ft of roof surface. Zinc sheet or shingle roofings with underlay of 24- pound asphalt-saturated rag-felt in one or two thick- nesses or 14-pound unsaturated or asphalt-saturated

asbestos-felt. Wood shingles with butt thickness not less than

Ys inch laid with not less than 6-inch head lap, coated on bottom with asphalt emulsion weighing not less than 4

lb per 100 sq ft of roof surface, except for upper 2

inches, and on top and three edges with asphalt weighing not less than 60 lb per 100 sq ft of roof surface, into which are embedded granules of crushed slate weighing

not less than 116 lb per 100 sq ft of roof surface. Shingles are to be laid over slat or close %-mch. wood

sheathing.

Class 4. Roof coverings

Asphalt rag-felt mineral-surfaced roll roofing laid in single thickness with 2-inch or more end and side laps,

weight not less than 75 lb per 100 sq ft of roof surface. Asphalt rag-felt smooth-surfaced roll roofing laid in single thickness with 2-inch or more end and side laps, weight not less than 35 lb per 100 sq ft of roof surface. Wood shingles of not less than %-inch butt thickness chemically treated under pressure with double treat- ment of sodium borate and zinc chloride with evacuation and drying between treatments laid with 6-inch or more head lap. Edge-grain red cedar, redwood, and No. 1 pine

shingles ^^e-inch butt thickness, 18 inches long, laid with 5-inch weather exposure on %-inch square-edge

wood sheathing with boards spaced not more than %

inch apart. Edge-grain red cedar and redwood shingles, %-inch

butt thickness, 16 inches long laid with 5-inch weather

exposure on %-inch tongue-and-groove wood sheathing.

Edge-grain red cedar and redwood shingles, ^^-inch butt thickness, 16 inches long laid with 5-inch weather

exposure on %-inch square-edge wood sheathing with

boards spaced not more than J4 inch apart and asphaltor tar-saturated rag-felt between shingles and sheathing.

Wood shingles of any species %-inch or greater butt

thickness, 16-inch or greater length, laid with not less than 6-inch head lap on %-inch square-edge or tongueand-groove wood sheathing, space between boards not more than }i inch and underlay between boards and

shingles of asphalt-saturated rag-felt in one or two

layers, weighing not less than 24 lb per 100 sq ft or asphalt-saturated asbestos-felt weighing not less than

14 lb per 100 sq ft. Red cedar, redwood, or No. 1 pine shingles, butt

thickness not less than % inch, 16-inch or greater

length, laid with not less than 6-inch head lap on %-inch

square-edge or tongue-and-groove wood sheathing, space between boards not more than }i inch, shingles before application to be dipped to within 2 inches of the top in mineral oxide paint thinned so the weight of pigment is not less than 30 percent of the weight of the prepared paint, and a brush coat of the unthinned paint

applied over the exposed length after application on the

roof. Class 5. Roof coverings

Wood shingle constructions not included under

Class 4. Paragraph 900. General

In localities where weather conditions make it justifiable, a provision might well be included to the effect that appliances capable of heating habitable rooms to a temperature of 70° Fahrenheit at all times shall be

provided.

Paragraph 901-12. Special Types of Chimneys

Tests are now in process at the National Bureau of Standards on various special types of chimneys. It is expected that the information obtained from these tests

will provide a basis for determining what types are

acceptable.

Paragraph 903. Fireplaces

It is important that a fireplace should have correct dimensions, not only for proper functioning as a heat

appliance but also to guard against hazards from sparks

thrown out by down drafts. The matter of correct dimensions is discussed at some length on pages 35-43,

inclusive, of Farmers' Bulletin 1889 Fireplaces and

Chimneys, issued by the United States Department of Agriculture, dated December 1941. It is recommended

that fireplace dimensions be made to conform to the recommendations contained in that document.

Paragraph 908. Mechanical Circulation Warm-Air

Systems

The standards mentioned in Section 908-1 are obtainable from the National Board of Fire Underwriters, 85 John Street, New York, N. Y. The Practical Code for the Design and Installation of Mechanical Warm Air Heating Systems, applicable

only to the average small installation, and the Technical

Code for the Design and Installation of Mechanical

[74]
'Warm Air Heating Systems, both issued in June 1940 by the National Warm Air Heating and Air Conditionjing Association, are obtainable from the association, 5 East Long Street, Columbus, Ohio, for 25 and 50 cents,

respectively.

^ Paragraph 910. Appliances

' The requirements mentioned in Section 910-1 (a) are 'obtainable from the American Gas Association, 420

Lexington Avenue, New York, N. Y., for 40 and 50

i cents, respectively.

NBFU Pamphlet No. 58, containing the standards mentioned in Section 910-1 (f), is obtainable from the National Board of Fire Underwriters, 85 John Street,

• New York, N. Y.

' The code mentioned in Section 910-3 is obtainable from the American Society of Mechanical Engineers,

' 29 West 39th Street, New York, N. Y., for 75 cents, with a 20-percent discount to ASME members.

I Information concerning Commercial Standards may

be obtained from the National Bureau of Standards,

! Washington, D. C. The Commercial Standards menI tioned in Section 910-2 and in Section 910-4 are

i obtainable from the Superintendent of Documents,

j Washington, D. C, for 5 cents each.

' Paragraph 1000. Safeguaeds Against Accidents

i

j For further information on measures tending to

! reduce hazards in and about dwellings, see Principle 29,

I of Basic Principles of Healthful Housing, Second

,j Edition, May 1939. This report of the Committee on

the Hygiene of Housing of the American Public Healtli

I Association, 1790 Broadway, New York, N. Y., is

i obtainable from the association for 25 cents.

Paragraph 1101. National Electrical Code

The National Electrical Code is obtainable from the National Board of Fire Underwriters, 85 John Street, New York, N. Y., for 5 cents.

Paragraph 1201. Plumbing Standards

Emergency Plumbing Standards for Defense Housing

is obtainable from the National Housing Agency,

Washington, D. C.

Paragraph 1202. Sanitary Fixtures

For further information on sanitary fixtures, see Part VIII of Sanitation Code for State or Local Adoption,

May 1941, obtainable from the United States Public

Health Service, Washington, D. C.

Rats

In localities where it is established that rats exist in

sufficient numbers to constitute a health hazard, code

requirements concerning ratproofing are justified. For

information on this subject see Principle 21, of Basic

Requirements for Healthful Housing, Second Edition,

May 1939, a report by the Committee on the Hygiene

of Housing of the American Public Health Association, 1790 Broadway, New York, N. Y. The report is obtainable from the association for 25 cents. The Rat and Ratproof Construction of Buildings,

Supplement No. 131 to the Public Health Reports,

issued by the United States Public Health Service and

obtainable, for 15 cents, from the Superintendent of Documents, Washington, D. C, includes specifications

and a Model Ratproofing Ordinance.

Noise

Although no specific requirements regarding noise are contained in the Code, it is recognized that measures to exclude or reduce excessive noise are desirable. Such

measures are discussed in Principle 7, of Basic Principles

for Healthful Housing, Second Edition, May 1939, a

report by the Committee on Hygiene of Housing,

American Public Health Association, 1790 Broadway,

New York, N. Y. The report is obtainable from the

association for 25 cents. Ultimately, these measures may find their way into mandatory requirements, but

for the present they are cited merely as good practice.

[75]

I

INDEX

A Page

Accidents: Information on prevention 75 Safeguards against 43 Adjoining property, protection of 19

Air, recircillation of 41 Air spaces for wood girders 33

Alley:Definition -- 8 Included in yard area 14 Allowable stresses in reinforced concrete 27 American Concrete Institute, address 45 American Gas Association, address 75 American Institute of Steel Construction, address _ 45 American Iron and Steel Institute, address 45 American Lumber Standards, information on... 45 American Public Health Association, address 75 American Society of Mechanical Engineers, address 75 American Society for Testing Materials, address 45, 72 American Standards Association, address. 44,45 American Wood Preservers' Association, address 45 Anchorage: Of beams -.- 31 Of floor joists - 31 Of girders -.- 31 Ofjoists 31 Of reinforced-concrete walls.. ._ 26 Of wall facing.-.. 24 To resist wind loads 18,22 Appliances - 42

Oil-fired 42

See also Gas appliances. Approved, definition 8

Arbors: Not court obstructions.. 15 Not yard obstructions - 15 Arches 25 Design of --- - 45 Loads on.. 25 Materials 25

Stresses 25 Area:Definition - - 8 Limitations - .- 12 Of courts 15 Of flues 38 Of habitable rooms 13 Attachment of veneer 24

Attics: Area required for storage. 72 Draft stops between dwellings 72 Loads 18 Roof construction over. 11 Storage use 34 Automatic stokers - 43 Source of standards.. 75

-\.wnings: Not court obstructions - 15 Not yard obstructions 15

Back-plastered construction, stucco on 70 Back plastering of stuccoed walls

Balustrades Basement stairways Doorway width

Enclosure

Outside Basements: Bathrooms in Columns

Definition Foundation walls of Glass area of windows

Openable area of windows

Suspension of water pipes Wall thickness Wood construction in See also Cellars. Bases:For heating furnaces. For ranges For stoves.

Page

Bathrooms:

Access to 13 Basement 13 Glass area of windows 14 Light and ventilation 13 Not to open into kitchen. _ 13 Openable area of windows. 14 Return duct prohibited 42 Skylights. 13 Windows -.. 13 Bathtub or shower, required 43 Beams:

Anchorage of 31 Bearing on masonry 26 Bridging 31 Built-up 32 Built-up, nailing of 70 Clearance from chimneys. 34 Column bearing for 32 Design of columns to support. 71 Notching of 32 Plan k-and-beam construction 32 Posts to support 71 Protection of reinforcement 26

Second-floor, bearing for 71

Size _ 32 Spacing 32 Support over openings 32 Wood, support of 32 Bearing, for second-floor beams 71 Bearing partitions. See Partitions, bearing. Bearing walls. See Walls, bearing. Bedrooms:

Access to bathrooms 13 Minimum area 13 Belt courses: Not court obstructions 15 Not yard obstructions 16 Board of appeals ._ (note) 8 Boiler code, source of 75 Boiler rooms, fire resistance of _. 34

Boilers, steam and hot-water 42

Bolts, working stresses 28 Bond:

Cavity walls 23 Faced walls 24 Hollow walls of solid units 23

Solid brick walls 22 Stonewalls 23 Walls of hollow masonry imits 22 Bonding: At intersections 25 Of chimneys 37 To resist wind loads 22 Bracing: Diagonal, of exterior walls 29 Stuccoed walls 30,70 Brick:Clay or shale 20 Quality of.. 20 Brick masonry. See Brick walls, solid; Reinforced brick masonry.

Brick walls, solid 22 Bond 22 Diagonal headers 22 Headers 22 Thickness 22 Bridging 31 Where required 70 Building, definition _. 8

Building area, definition 8 Building code, none, procedure (aote) 7 Building felt, in floors 70 Building lines 13 Building official, definition _ 8 Building paper, in floors. 70 Building restrictions 12 Building site: Drainage of 33 Removal of debris 33 Removal of stumps and roots 19 Buildings:

Basis of classifications 44 Classifications 44 On same lot 16 Built-up roof coverings 72

[77]
Buttresses: Page

For foundation walls 20 In lieu of increased wall thickness 26 G

Cast steel, working stresses 28 Cavity walls. See Hollow walls; Walls, cavity.

Ceilings: Beams, support of . 32 Loads . - 18 Smoke pipes through 39

Cellars: Definition 8 Foundation walls ' 20 Glass area of windows 14 Openable area of windows 14 Stair enclosure 16 Wall thickness - 26 See also Basements.

Certificate of inspection 8 Change in direction of fJues- -- 38 Change in interior dimensions of chimneys 37 Chases.- 25 Area 25 Cutting into walls prohibited 25 Depth _.. 25 Filling 25 Length 25 Not to reduce fire resistance 25 Chimneys:

And heating appliances 36 Bonding of _ --- 37 Building walls a part of 37 Change in interior dimensions _ 37 Concrete 37 Connection of gas appliance vents 42 Construction __ 36 Corbeling 37 Fire separation 34 Firestopping aroimd 35 Flashing 37 Footings 19 Foundations 37 Height. _ 37 Hollow masonry units . 37 Insulation of furring strips 34 Materials 36 Projection of lining 37 Eeinforcement - - 37 Solid concrete block 37 Special types - 38,74 Stone -. 37 Thimbles 39 See also Flue lining; Flues.

Classifications, fire-resistance 11,44 Basis of recommendations 44 Source of information 72

Classification, roof coverings 36 Classifications of construction 11 Doubtful 12 Source of information 72 Clay tile, structural: For non-load-bearing masonry 21 Use in isolated piers 24 Cleaning of flues 38 Clearance under buildings - 33 Clearances from combustible construction: Chimneys 34 Fireplaces 39 Gas ranges 40 Heating furnaces 40 Outlet pipes 42 Smoke pipes -.- 39 Steam and hot-water pipes 42 Stoves and ranges 40 Warm-air ducts 40,41 Clearing of building site 19, 33 Closeness of wood to ground 33 Closet beneath stairs, firestopping of 35 Closet space, not included in room area 13 Clothes poles: Not court obstructions 15 Not yard obstructions 15 Coal bins, fire resistance of 34 Cold-air ducts 41 Collar beams: ~

Size 70 Spacing 70 Columns:

Anchorage 18 Corbels 71 Design of, to support beams 71 Fire resistance -- 11 In lieu of increased wall thickness 26 Information on stresses . 45

Interior, in plank-and-beam construction 32, 71 Notching of 71 Protection of reinforcement 26

Size of 32

Steel, working stresses 27 Wood posts 29

Combustible construction, clearances from: Page

Chimneys 34 Fireplaces 39 Gas ranges _ 40 Heating furnaces 40 Outlet pipes 42 Smoke pipes.- 39 Steam and hot-water pipes 42 Stoves and ranges 40 Warm-air ducts 40, 41 Combustible construction, passage of smoke pipes through 39 Combustion 43 Commercial Standards: Source of 45,75 Source of information on _. 75 Common property line: Definition g Space to dwelling 34 Common-property-line walls. See Walls, common-property-line. Compliance, partial 12 Concentrated loads 26 Concrete:

Bases, for wood construction in basements 33 Bases, for wood posts 29 Brick _ 20 Chimneys 37

Fill, under footings 19 Filling for tile at wall ends... 25 Foundation walls 20 Masonry units 21 Mix 26 Protection to insure curing 27

Slabs, for wall anchorage 25

Slabs, foundation substitute 19 Concrete, plain 21 Definition 8 Walls 22 Concrete, reinforced, definition 8 Concrete, reinforced. See Reinforced concrete. Concrete walls 22 Reinforcement 23 Thickness 22 Connections:

Details and 17 Of shafts, to adjoining construction 36 Of smoke pipes with flue 39 Construction 17 Exterior-Protected 11 Fireproof 11 Incombustible 11 Masonry 20 Nonconforming, permitted 7 Of chimneys 36 Of flues 38 Of stairways 16 Reinforced brick masonry 27 Reinforced concrete 26

Steel and iron 27 Strength of 17 Types of 11 Wood 28 Wood-Frame 12 Construction classifications. See Classifications of construction. Construction methods: Newly developed 7,44 Not specifically authorized 7 Cooking space 13 Corbeling of chimneys 37 Corner bracing, stuccoed walls. 30 Cornices 26 Exterior, firestopping 35 Metal, support of 26 Not court obstructions 15 Not yard obstructions 15 Stone, support of 26 Terra cotta, support of... 26 Courts 15 Area 15 Definition- 8 Depth 15 Drainage 15 Height, definition 9 Inner, definition - 9 Intakes 15 Length, definition -.- 9 Outer, definition- - 9 Paving 15 To be unobstructed 1 15 Width 15 Width, definition 9 Crawl space under buildings -_ 33 Cutting of treated wood 33 D

Dead load. See Load, dead. Decay, termites and 33, 71 Decay prevention, source of information 71 Defense housing critical list (note) 8 Definitions 8 Built-up roof coverings (note) 72 End lap and head lap 73

[78]
Definitions—Continued. Page

Plank-and-beam construction (note) 32 Plywood - - 32 Prepared roof coverings.- _ (note) 73 See also index entry for specific word defined. Demolition.- 7 Design - - 17 Computations waived 18 For loads 18 Of anchorage (note) 18 Of flat panel with stressed coverings 32, 71 Of footings 19,45 See also specific subject. Details and coimections. 17 Determination of required sizes of wood members 28 Diagonal bracing of exterior walls 29 Dining space _-- 13 Distance to exits 16 Distribution of exits 16 Doors:

Access to crawl spaces 33 Between dwelling and garage.. 35 Flashing over... 33 For basement or cellar stairs. 16 Hanging of 17 Metal lined, for shafts 36 On exit stairways 17 Screening of - - 44

Sliding, firestopping of 35 Support of beams over 32 Doorways, exit 16 Width.. 16 Doubtful classifications 12 Draft stops, in attics, between dwellings.. 72 Drain tile 20 Drainage: Of building site - — _ 33 Of cavity walls 23 Of courts 15 Of space beneath buildings. 20 Over doors and windows 33 Ducts:

Firestopping 35 Heating system _ 40 Notching of studs - 30 Return. — .- 42 Dwelling units: Definition... 9 Fire separation 34 Firestopping of partitions between 72 Number per 4,500 square feet 12 Number per 3,000 square feet 12 Recirculation of air 41 Dwellings: Covered by this code... 7 Definition 9 Draft stops between attics __ 72 Fire separation 34 Sanitary fixtures for 43 Screening of 14,44 Yards required 14 E

Electric-light outlets, location 44

Electrical - - 43 Enclosure: For shafts, required 36 For stairways 1[; Of public hallways 17

"Wall, definition 10 Enclosure walls. See Walls, enclosure. End lap, defined 73 Engineer to design framing around openings. 70 Equipment, electric -- 43 Source of code on 75 Erection of masonry 26 Excavations: Cost of protection 19 Protection of adjoining property 19 Existing walls - 26 Exit stairways. See Stairways, exit. Exits 15 Distance to - 16 Distribution of 16 Doors, hanging of 17 Kinds of 15 Location - 16 Number of 15 Obstructions 17 Width, reduction 17 Expansion joints, sealing of 33 Exterior-Protected construction 11 Area limitations 12 Exterior walls. See WaUs, exterior.F

Faced walls - 24 Bond -- --- 24 Definition - - 10 Materials 24 Thickness 24

Faced walls—Continued. Page

Thickness of facing 24

See also Veneer; Veneered masonry walls. Fastenings: In plank-and-beam construction. 32

In plywood construction 33 Federal Housing Administration, standards of -- 45 Federal Specifications, source of 45

Filled ground _ 18 Fire-division walls: Definition _ 10 Fire resistance of. H

Fire doors: Between dwelling and garage 35 Definition 9 For hazardous spaces. 34 For shafts 35

Fire escapes, not exits 15 Fire partitions: Definition. 10

Fire resistance of 11 Fire prevention, in fireplace construction 39 Fire protection 34

Fire resistance: Chases and recesses not to reduce 25

Classifications 11,44

Classifications, basis of recommendations., 44

Classifications, source of information... 72

Definition 9 Determination of 34 Doubtful classifications 12 Information sources 72 Of common-property-line walls 11, 12' Of construction separating dwelling imits 34 Of exterior walls ... _ __ 12 Of fire walls 11,12^ Of fireproof buildings 44 Of fireproof construction 11 Of garages 34 Of hazardous spaces 34 Of party walls 11,12 Of public hallway enclosures 17 Of public hallways - 16- Of roof coverings 36 Of shaft enclosures 36 Of stairway enclosures 16 Reduction prohibited.. 8 Research on 72 Roof coverings not included 73 Source of specifications. 72

Fire-resistive filUng between structural members 25

Fire separation. 25,34,38,72 Of chiirmeys 34 Fire tests of partitions, information on 72

Fire walls: Construction of 34

Definition 10 Fire resistance of 11,12 For area limitation 12 In Exterior-Protected construction 12 In fireproof construction H

In incombustible construction H

In Wood-Frame construction.. 12 Number of dwelling units between 12" Thickness 26

Firebrick, use in fireplaces 38

Fireplaces 38, 74

Clearance for header beams 39 Clearance for mantels 39 Clearance from combustible construction 39 Dimensions 74

Fire prevention 39 Hearths 38 Lining of --. 38 Of hollow units 38 Removal of wood centering 39

Start of flue lining 38 Stone 38

Fireproof construction Garages.. 34

Firestopping 70 Between dwelling units 7-

Closet beneath stairs 35

Exterior cornices 35

Exterior walls. _ 35

Floors 35 Furred spaces. _ Inspection

Interior partitions Nonbcarlng partitions Partitions Pipes or ducts Removal for pipes, etc ^5

Sliding doors Spaces around chimneys — - ^5

Stairs... Stairs over basement stairs ^5 Fixed registers

179]
Flashing: Page

Cavity walls. _ 23 Chimneys _ 37 Masonry veneer 29 Over doors and windows, _ 33 Stucco 29 Flat panel with stressed coverings 32, 71 Construction of 71 Headers for 71 Strength and stiflness - 71 Floor furnaces: Registers for... 41 Wall and comer clearances for 41 Floor loads _ 18 Reduction in 18 Flooring, finish: Laying of __- 70 Thickness 70

Floors: Area limitation affected by.- _ 12 Clearances for steam or hot-water pipes 42 Clearances for warm-air ducts 41 Construction, above garages 34 Expansion j oints, sealing of __ 33 Fire resistance 11, 12 Firestopping 35 Garages, construction - 35 Glued plywood - - 32 In incombustible construction 11 Laying finish flooring 70 Mounting of heat appliances 39 Number of dwelling units between fire walls.. 12 Rafters fastened to 70

Sleepers, wood preservation 33 Smoke pipes through 39 Support 71 Support of beams _ 32 Wood construction 30 Plue lining -. 38 Beginning of 38 Not to be cut into -.. 38 Omission of - 38 Staggered joints 38 Flues 38 Area reduction prohibited 38 Areas 38 Change in direction 38 Cleaning 38 Construction --. 38 Dimensions 38 For gas appliances 38 Gas-appliance vent coimection 39 Separation 38 Smoke-pipe connection 39 Venting... 38 Footings 19 Concrete fill -- 19 Design of 19.45 Drain tile 20 Federal Housing Administration standards 45 For wood posts 29 Materials 19 Mortar for 21 0f chimneys 37 Projection 19 Protection of reinforcement 26 To solid ground or rock 19 Wood.- ._ 19 Forms, removal of -- 27 Foundation walls .- 20 Buttresses for .- 20 Concrete walls 20 Height above groimd 20 Increased thickness 20 Loads 20 Masonry walls 20 Mortar for 21 Pilasters for 20 Reinforced brick masonry walls 20 Reinforcement of 20 Rubble stone walls . 20 Strength 20 Thickness... '0. ^« Vents ^jj Waterproofing 20 Foundations 19 Anchorage to Depth 19 Footings c---: "iv ; S Insulation of porches, steps, and terraces from Of chimneys °5 Pile 10 Required

Substitute for 19 Termiteproofing 33 To support party walls 1" Framing, interior, in Exterior-Protected construction 11 Framing around openings, designing by engineer 70

Framing over openings: Page

In bearing partitions _ 30 In bearing walls.. 30,70 Freezing, protection against, for masonry .' 26 Frozen ground 19 Frozen materials 26 Furnaces. See Heating furnaces. Furred spaces, firestopping 35 Furring: Attachment aroimd chimneys 34 Insulation of, around chimneys. 34 Metal reinforcement for stucco 30

Strips, wood preservation 33 G

Garages: Attached to dwelling 35 Dwelling openings into . _ 35 Fire doors 35 Fire resistance-- 34 Fireproof - 34 Floor construction 35 Heating-- _ 35 Return ducts prohibited 42 Gas appliances 42 Flue area for 38 Source of re quirements 75 Vent connection to smoke-pipe flue 39 Venting 42 Gas logs 42 Gas ranges, clearances from combustible construction 40 Gas-fired furnaces 42 General building restrictions 12 Girders: Anchorage of 31 Bearing on masonry 26 Fastening of 32

Fire resistance 11 Framing of joists into 31 In masonry walls 33 In reinforced-concrete walls 33 Joints in 31 Loads 18 Location of joints in _. 31 Partitions supported by _ _ 30 Protection of reinforcement 26

Steel, working stresses 27, 28 Wood 30 Wood preservation 33 Glass area: Of skylights 14 Of windows 14, 44 Glue specifications 32 Gluing plywood to framing members 32, 71 Grade, finished, definition 9 Grade, lumber, definition 9 Grade, natural, definition 9 Grading of wood members 29

Grilles, for court intakes 15 Ground. See SoU. Gypsum block, restricted use .......i...^ 21 H

Habitable rooms:

Access to 13 Access to bathrooms 13 Below finished grade 13 Courts serving 15 Definition 9 Glass area of windows 14,44 Heating of-- 74 Light and ventilation 13 Light distribution 14 Minimum area 13 Minimum height.. 13 Minimum width 13 Number of windows 13 Openable area of windows 14 Ventilation 44 Half story : Definition 10 Room area 13 Room height 13 Hallways. See Public hallways. Handrails: For exit stairways 16 For stairways. 43 For steps 43 Hanging of doors . 17 Hazardous spaces, fire resistance... 34 Head lap, defined 73 Header beams, clearance over fireplaces 39 Headers: Design 31,70 Diagonal 22 Doubling, when not required 31 In faced walls 24 In solid brick walls 22 In veneered walls... 24 Nailing of 70 Number of tail beams 70

[80]
Page

Headroom of stairways — 16 Health requirements, reduction prohibited _ 8 Healthful housing, basic principles _ 44,75 Hearths: For heat appliances _ 40 Incombustible 38 Heat appliances: Combustion - 43 Mounting of 39 Heating:

Electric wiring and equipment for ' 43 Of garages — 35 Of habitable rooms.. _ 74 Heating apparatus, safeguards from contact 17 Heating appliances, chimneys and _-- 36 Heating furnaces: Bases for _ _ 40 Clearances from combustible construction 40

Gas-fired 42 Heating system:

Registers _ - 41 Warm-air ducts 42 Height:

Building, definition 9 Court, definition 9 Limitations 12 Of chimneys - 37 Of existing walls -.- 26 Of foundation walls - - 20 Of habitable rooms 13 Of parapet walls. 24 Of piers 24 Story, definition 9 Wall, definition 9 See also specific topic. Hollow concrete masonry units 21 Use in isolated piers 24 Hollow isolated piers 24 Hollow masonry units for chimneys 37 Hollow walls: Chases and recesses in 25 Definition — 10

Fire-resistive filling 25 See also Walls, cavity; Walls of hollow masonry units. Hollow walls of solid units 23 Bond 23 Decreased thickness 23 Height 23 Thickness 23 Hot-water boilers 42 Source of code 75 Hot-water pipes 42 Clearances from combustible construction 42 Coverings... 42 Housing, permits for temporary 44

I

Incinerator rooms, fire resistance of 34 Incombustible, definition '. 9 Incombustible construction 11 Area limitation 12 Roof coverings over 11 Incombustible hearths 38 Incombustible material: Around registers 41 Aroimd steam and hot-water pipes.. 42

Filling for chased walls 25 In partition openings 39 In walls backing radiators 25 Replacing firestopping 35 Increased stresses in reinforced concrete 27

Increases in working stresses 18

Insects. See Termites.

Inspection: Of firestopping 36 Ofwlring 43 Insulation of combustible members near chimneys 34 Intakes of coinrts... 15

Interior columns in plank-and-beam construction 32

Interior doors, not exits 17 Interior partitions 30 Firestopping 30 Load-bearing capacity 30 Plates 30 Support of 30

Intersections, masonry walls, bonding 25

Iron. See Steel and iron construction.J Jambs In bearing walls _ 30

Joints: Expansion, sealing of 33 In girders, location 31 Plywood, glued 32 Shearing stress 29

Joists: Anchorage of 31 Bearing on masonry 26 Bridging. 31

Joists—Continued. Page

Ceiling, spiked to rafters 70 Clearance from chimneys 34 Decreased spacing 31 Double, supporting interior partitions 30 Doubling of 31 End notching of 31 Increased size 31 Increased stresses. _ 29 Metal hangers.. 31 Nailing of 1 30 Notching of. _ 31

Steel 28

Steel, protective coating 28

Stress tables _ 52-61 Support of.. 30 Supporting nonbearing partitions . 31 Tying to girders or to joists 31 E

Kinds of exits 15 Kitchens: Areaof... 13 Bathroom not to open into 13 Glass area of windows 14 Return ducts prohibited. 42 L

Landings I6 On exit stairways _ 17 Lateral support , masonry walls. _ 22 Latitude, effect on natural lighting 44 Lavatory, req uired 43 Ledger board 31 Light and ventilation 13 Bathrooms _ 13 Exit stairways 16 Habitable rooms 13 Public hallways.. 17 Rooms 13 Water-closet compartments 13 Light steel construction """" 28 Source of information 45

Lighting, artificial: Electric wiring and equipment for 43 Of public hallways 44

Lighting, natural: Distribution of ___ 14,45

Effect of latitude on 44 Of public hallways 44 Lime for lime mortar 45 Limitations

__

12 Area 12 Height 12 Lines, building 13 Lintels 25 Definition I 9 In bearing partitions 70 In bearing walls 30 Loads on 25 Materials of 25 Nailing [.V/. 70 Nonreinforced masonry.. 25 Reinforced masonry

.

. ___ _ 25

Size of. 30 Span formula ... 70

Steel... 25 Stone 25 Studs cut to receive 30 Liquefied petroleum gases... ...II 42 Source of standards II 75 Living rooms, minimum area. 13 Load-carrying capacity:

Exterior walls 29,70

Interior partitions _ 30 Loading 24 Load, dead, definition 9 Loads 18 Arches. I 25 Concentrated 26 Effect on stresses

.

... 29 Exterior walls.- __ 29,70 Foundation walls .. .. 20 Girders . 18 Increase not permitted 24

Interior column design 71

Interior partitions __ 30 Light steel construction 28

Lintels 25

Lintels and arches . . 25 Partition 25 Plank-and-beam construction...

..

71 Roof 31 Special provision for 71 Uniform on footings 19 Woodpiles 19 See also Floor loads; Wind loads. Location of exits 16 Lot, buildings on same 15 Lot, definition 9

[81]
Page

Lot line, definition 10 Lumber: Decay not permissible 33 Selection of 33 M

Mantels, clearance from fireplaces 39 Masonry 20 Arches 45 Bases, for heat appliances 39 Definition _-_ 10 Erection 26 Foundation walls-. _ 20 Mateiials, quality of --- 20 Miscellaneous requirements 25 Partitions 25 Piers 24 Protection against drying 26

Specifications 45 Support on wood prohibited 26 Units, cleaning of second-hand 8 Masonry vonecr: Attachment 29 Flashing 29 On Wood-Frame construction 2" Thickness _ 29 To rest on foundation _.. 29 Waterproofing 29 Masonry veneered walls, thickness 20 Masonry walls: Bonding at intersections 25 Chases and recesses 25 Girders in 33 Lateral support 22 Nailing blocks 26

Solid, lateral support 22 Materials:

Cellulose, protection of 33 Newly developed _ _ _ 7, 44 Not specifically authorized 7 Of chimneys 36 Of exit stairways 16 Of faced walls 24 Of footings 19 Of gas appliance venting 42 Of pile foundations 19 Of veneered masonry walls 23 Of warm-air ducts 40 Quality of- „- 17,20,45 Second-hand - 8 Substitute (note) 8 Workmanship 17 Mechanical circulation warm-air systems 41 Design of 41 Installation of 41 Source of standards , 74 Metal bearing plates 26 Metal cornices 26 Metal hangers for joists 31 Metal reinforcement for stucco 30 Miscellaneous requirements for masonry. _ 2,^ Mix, concrete 26 Model Ratproofing Ordinance, source of 75 Modification in exit widths 17 Moisture:

In walls --- 33 Moisture content of lumber (note) 33 Mortar for use in 21 Protection against 33 Mortar: Coverage in hollow-unit walls 22 For flue lining 38 For various uses 21 In reinforced brick masonry 27 In veneered walls 24 Lime for 45 Proportions --- 21 Types A, B, C, and D -- 21 Uses of Type D 22 Mounting of heat appliances 39 Multiple dwellings: Definition - 10 Exits - 15 Fire resistance of floors 12 Sanitary fixtures for 43 N

Nailing: Built-up beams 70 Furring strips around chimneys 34 Headers 70

Joists 30 Lintels 70 Masonry veneer to Wood-Frame construction 29 Metal reinforcement for stucco - 30 Not substitute for gluing 33 Plank 32 Rafters 31,70 Ribbon boards 30 Sheathing — 29

Nailing—Continued. Page

Sources of information 45 Structural members. _• 32

Tail beams " 70 Toe nailing 70 Trimmers 70 Wood members 28 Nailing blocks, in masonry walls 26 National Board of Fire Underwriters, address 74, 75 National Electrical Code 43 Source of 75 National Housing Agency, address 75 National Warm Air Heating and Air Conditioning Association, address - 75 Natural-draft oil burners 42 Newly developed materials and methods _ 7, 44 Noise 75 Exclusion, source of information 75 Reduction, source of information 75 Nonbearing partitions. See Partitions, nonbearing. Nonbearing walls. See Walls, nonbearing. Nonconforming construction, when permitted 7 Notching: Of beams 32 Of ends of joists 31 Of joists 31 Of studs 30 Number of e.xitS-_ 15 Numbering system in Appendix 44 O

Obstructions: In exits 17 In public hallways 17 Occupied, definition 10

Oil-fired appliances 42 One-pipe furnaces, registers for 41 Open spaces between buildings 15 Openable area of windows 14 Openings: Framing over _ 30

In partitions, prohibited 24 In shafts 36 In walls, prohibited 24 P

Painting of steel members 28 Panel coverings, fastenings of 33 Panel wall. See Walls, enclosure. Parapet walls. See Walls, parapet.

Partial compliance 12 Partitions, fire, definition 10 Partitions: Between dwelling units, flrestopping 72 Clearances for steam or hot-water pipes 42 Clearances for warm-air ducts 41 Fire resistance, information on 72

Fire tests, information 72 Flrestopping 35 Incombustible flrestopping in '_ 72

Interior. _ 30 Loads on 25 Masonry 25 Openings prohibited 24 Smoke pipes through 39 Thimbles in [ 39

Partitions, bearing 25 Definition jq Framing over openings [ 30

Lintels I 70 Over plank-and-beam construction 7] Thickness 25

Partitions, nonbearing:

Definition 10 Double joists supporting 31 Flrestopping 30

Joists supporting- 31 Masonry 25 Thickness 25 Party walls 13 Construction of 13 Definition - 11 Design of__ 13 Fire resistance of 11,12 In Exterior-Protected construction 12 In fireproof construction ' n

In incombustible construction 11 In Wood-Frame construction.-- _ 12 Materials of 13 Passage through combustible construction, smoke pipes, - 39 Paving of courts 15 Permits: Record of increased stresses 18 Special 7 Temporary 7,44 Petroleum gases, liquefied 42 Piers 24 Chases prohibited ..- 25 Definition -.. 10 Height 24

[82]
Piers—Continued. Hollow isolated - 24 In lieu of increased wall thickness _ _ 26 Increased loading prohibited 24 Mortar for - 21 Size 24

Pilasters for foundation walls - - 20

Pile foundations 19 Depth below ground 19 Materials 19

Piles. See under Wood.

Pins, working stresses 28 Pipes:Firestopping 35 For steam or hot water, coverings 42 Notching of studs _-- - 30 Sealing of floor and wall openings 33 Plain concrete. See Concrete, plain. Plank:

In plank-and-beam construction

_ 32 Length of --- -- 32 Nailing of 32 Protection against contraction . 70

Size 32 Plank-and-beam construction 32, 70 Beams 32 Definition.. (note) 32 Design 32 Exterior wall framing - - - 32

Interior coliunns 32 Plank ---- 32 Two-story construction. 71 Used with conventional framing 71 Plastering stuccoed walls 30

Plates: Doubling of 30 Exterior walls 30

Interior partitions.

_ - 30 Sheathing nailed to 29 Spliced joints 30 Platform framing, sheathing - 29 Plumbing 43 Plumbing standards 43 Source of -. 75 Plywood 32

Definition 32 Design of panels 32, 71 Gluing of panels 71 Gluing to framing members 32 Quality of .-- 32 Source of glue specifications. 71 Source of standard 71 Porches: Dimensions 43 Insulation from foundation and woodwork... 33 Kailingsfor 43 Uncovered, not court obstructions 15 Uncovered, not yard obstructions 15 Posts 29 For beam sui)port 32, 71 Power, electric wiring and equipment for 43 Prepared roof coverings 73 Preservation of wood 33 Privacy 13 Private water and sewage-disposal systems 8, 44 Property line, common, definition. 8 Protection: Of adjoining property 19 Of cellulose material - - 33 Of concrete, to insure curing 27 Of masonry, against drying 26 Of masonry, against freezing. 26 Of plank 70 Of reinforcement 26 Of steel members 28 Of warm-air ducts..- - 40 Public hallways 17

Artificial lighting -- 17,44 Enclosures of 17 Fire resistance. 16 Lighting - 17.45 Obstructions 17 Openings into 16 Ventilation ._ - 17 Width - 17 Public Health Service, U. S., address 75 Q

Quality of materials 17,20,45 R

Radiators, recesses for 25 Rafters: Clearance from chimneys 34 Fastening of. --- — 31,70 Increased size 31 Nailing of 31,70

Stress tables 58-69 Support of 31,70

EailiQgs for porches and terraces -- 43

Ranges: Page

Bases for.. Clearances from combustible construction Hearths for. ^ Ratproofmg, source of information 75 Ratproofing Ordinance, Model, source of 75 Rats 75 Rear yards. See Yards, rear. Recesses 25 Area... 25 Cutting into walls prohibited 25 For radiators 25

Lintels or arches 26 Not to reduce fire resistance 25 Recirculation of air 41 Register boxes 41 Insulation of 41 Registers, heating system... 41 Fixed registers ^ Floor furnaces.. 41 Furnace, clearances for 4J One-pipe furnaces 41 Setting... 41 Reinforced brick masonry 27 Foundation walls... 26 Source of requirements 45 Reinforced concrete 26 Definition g Foundation cap. 33 Mix 26 Protection of reinforcement. 26 Protection to insure curing 27 Removal of forms 27 Source of regulations 45 Walls 26 Walls, girders in. 33 Working stresses 27 Reinforcement: Of chimneys 37 Of foundation walls ._. 20 Of parapet walls 24 Of plain concrete walls... 23 Protection of 26

Steel, working stresses in 27 Removal:

Of buildings 7 Of debris 33 Of forms 27 Of wood centering of fireplaces 39 Requirements, miscellaneous, for masonry 25 Research on fire resistance 72

Restrictions: Building 12 Zoning 12 Return ducts _ 42 Ribbon boards 30 Nailing of 30 Rigidity of wood construction. 29

Risers: Minimum number in stairway 16 See also Treads and risers. Rivet steel, working stresses 27, 28 Rock, footings to rest on 19 Roof coverings 36,72 Built-up 72 Built-up, definition (note) 72 Class 1 36,72,73 Class 2 36,73 Class 3 36,73,74 Class 4 - 36,74 Class 5 36,74

Classifications 36 In Exterior-Protected construction 12 In incombustible construction 11 In Wood-Frame construction 12 Installation 72-74 Lapping of, defined 73

Lists of acceptable 72 Materials 72-74 Not included in fire resistance 73 Over combustible construction U

Over incombustible sheathing 11 Prepared 73 Prepared, definition (note) 73 Tests for nonlisted coverings 72 Roofs:Anchorage of. 18 Chimney height above — 37 Fire resistance of 11 Fire walls up to 34 In incombustible construction ._. 11 Increased loads (note) 18 Loads .- - 18 Sheathing 73 Smoke pipes through 39

Stress tables 58-69 Support of beams .— 32 Wind loads —- 18 Wood construction 30

[83]
Rooms:

Area in half stories. Below finished grade Light and ventilation See also Habitable rooms.

Roots, removal from site Rubble stone: Foundation walls Walls, thickness

Page

13

13

13

Safeguards against accidents... Information source Sand-lime brick Sanitary fixtures Source of information

Sanitation code

Source of Scope of code

Screen doors: To be self-closing To open outward

Screening 14,44 Mesh size 44 Of dwellings 14,44 Second-hand materials 8 Selection of lumber 33 Separation: Of combustible structural members 25 Of flues 38 Setting of registers 41 Settlement, equalizing of 18 Sewage-disposal systems, private 8, 44 Shafts 36 Connection to adjoining construction.

Definition _.. Fire doors Metal lining Metal-lined doors Openings in Sheathing _ In incombustible construction Nailing Platform framing

Roof.

Shields, metal, for stoves and ranges... Side yards. See Yards, side.

Sills, sheathing nailed to 29 Sink, kitchen, required 43

Site of building, See Building site. Skylights: In bathrooms 13 In exit stairways 16 In water-closet compartments 13 Openable area 16 Ventilating 14 Sliding doors, firestopping of 35 Smoke flue connections 42 Smoke pipes 39 Clearances from combustible construction 39 Connection with flue 39 Passage through combustible construction. 39 Snow loads (note) 18

Sofl:Bearing capacity 18 Filled ground 18 Footings to solid groimd 19 Frozen ground 19 Normal conditions 18 Safe carrying capacity 18 Varying conditions 18 Solid brick walls. See Brick walls, solid. Solid concrete block, chimneys of.. 37 Solid concrete masonry units. 21 Space between dwellings 34 Spandrel walls. See Walls, spandrel.

Special types of chimneys 38

Specifications, sources of 45

Splicing: Joints in plates 30 Wood members 29

Stairs, firestopping of 35 Stairways 16,43 Construction. Handrails Headroom

Over basement stairs, firestopping. Width

Stairways, exit Balustrades Construction Doors on Doorway width

Enclosures for -. Handrails - Headroom

Landings

Landings at doors Lighting

Materials

Stairways, exit—Continued. Page

Openings into enclosures of ig Risers, minimum number of 16 Treads and risers _ jg Ventilating skylight... II"-". ""II] 16 Ventilation. - . . -la Width I.IIIIIIIIiri ig Width reduction by doors _ _ Winders prohibited ^ ._' " "

jg Standard fire test, definition. jq Standards, sources of _I.II ac Steam boilers Source of code Steam pipes Clearances from combustible construction 40 Coverings IIIIII" 40

Steel and iron construction " 27 45 Miscellaneous requirements.. ...I.'I Source of specifications ' 7?

Steel Joist Institute, address ------- - Steel members:

Joists...... 28

Joists, evidence of safety 1-111-11111-11" ^ Protection IIIIII S Separation of unprotected structural members- — II oc Thickness S2

Steps: ^

Handrails 43 Insulation from foundation and woodwork I 33 Not court obstructions . 15 Not yard obstructions.. IIIII.II " 15 Stokers, automatic .- Source of standards. -- I 71; Stone IIIIIIIIIIII"""" 21 Ashlar, for faced walls HI " 24 Ashlar veneer, thickness-- "I ' 04 Chimneys . " 37 Cornices I] og Fireplaces 30 Stone walls - 00 Bond 5; Thickness "

' 03 Storage: Area, not included in room area

.

13 Attic IIIIIII.I I ig Attic area IIIIIIIIIIIIIII 72 Fire resistance of storage rooms.. . 94 Story:

" Definition jq Half story, definition IIIII

""

.. 10 Height, definition ' 9

Stoves: Clearances from combustible construction . 40 Hearths and bases for 40

Street, definition.. III.IIII 10

Stress tables for wood construction. IIIII. IIIIIIIII" 46-g9

Stresses. See Working stresses. Structural Clay Products Institute, address 45

Structural clay tile 2I Structural members:

" Bearing on masonry 26 Reinforcement in. ...IIII 28

Restrictions on reuse I.IIIIIII""' 8 Separation of combustible IIIIIIII 25 Structural steel, working stresses IIIIII 27 28 Structure, definition IIIIIIIIII ' 10 Stucco, thickness on metal lath IIIIIII 30 Stucco on Wood-Frame construction ..IIIII 29 70 Back plastering I. II. .II '30 Bracing, corner and waU ' 30 Flashing IIIIIIII 29 Metal reinforcement II""" 30 Waterproofing .

' 30 Studs:Cutting for lintels or headers 30 Doubling of, in bearing walls 30, 70 Notching of 30 Spacing of _. 32,70

Steel, protective coating 28 Stumps, removal from site 19 Substitute materials (note) 7 Support:

Lateral, of masonry walls 22 Of rafters 31,70 On wood, prohibited 26 Suspension of water pipes 33 T

Tail beams:

Nailing of 70 Number to a header 70 Temporary housing, permits for 44 Temporary permits. 7, 44 Termites and decay 33, 71 Termites, protection against 29, 33 Foundations 33 Where required (note) 33 Terra-cotta cornices 26

Terra-cotta veneer 24

[84]
Terraces: Page

Dimensions 43 Insulation from foundation and woodwork 33 Not court obstructions— 15 Not yard obstructions _ 15 Railings for 43 Test data waived 18

Tests:For nonlisted roof coverings 72 On special types of chimneys 74 Thickness. See specific topic. Thimbles: For chimneys 39 In partitions, for smoke pipes 39 Tie beams 70 Tie rods 23

Tile:Filling at wall ends 25

Flat, veneer 24 Timber:

Decorative 26 Prohibited in masonry__ 26 Timber connectors, information on use 45 Toenailing... 70 Treads and risers 16

Trellises, garden: Not court obstructions 15 Not yard obstructions 15 Trimmers:

Design 31,70 Doubling, when not required 31 Nailing of — 70 Trusses:

Fire resistance of- 11 In bearing walls 30 Types of construction 11 U

U. S. Public Health Service, address. 75 Unobstructed:

Courts to be - 15 Yards to be 15 Use of firebrick 38 V

Vapor-resistant barrier for exterior walls 33 Varying soil conditions 18 Veneer: Attachment of 24 Not part of wall thickness 24 Thickness 23 Veneered masonry walls 23 Attachment of veneer 24 Loading 24 Materials 23 See also Faced walls; Veneer. Veneered wall, definition 11 Ventilating openings, screening of 44 Ventilation 13,44 Beneath buildings 33, 71 Beneath wood construction 32, 33 Cross ventilation (note) 14 Exit stairways 16 Habitable rooms 44 Public hallways 17 Skylights 14 Through ventilation (note) 14 See also Light and ventilation. Venting, of gas appliances .- 42 Vents, foundation wall 33 For wet ground 33 W

Wall, faced, definition 10 Wall, fire, definition 10 Wall, fire-division, definition 10 Wall, hollow, definition 10 Wall, party, definition 11 Wall, veneered, definition 11 Wall anchors, for faced walls 24 Wall openings: Bonding ties 23 Concrete reinforcement 23 Lintels or arches 25 Prohibited 24 Wall ties, in veneered walls 24 WaUs:

Anchorage.-. -.- 18 Bracing of stuccoed walls 30

8-inch, chases and recesses in 25 Existing 26

Fire resistance, information on 72 Height, definition. 9 Increased height of existing 26 Junctions, reinforcement 23 Moisture in 33 Mortar for linings 21 Openings prohibited 24 Plank-and-beam construction 32

Walls—Continued. ^ae®

Rafters fastened to 70 Reduction of thickness 25

Sealing of pipe openings 33 Separation of structural members -- 25 Thickness - 26 Use of existing... - 26 Vapor-resistant barrier. _ 33

See also Brick walls, solid; Concrete walls; Faced walls; Fire- division walls; Fire walls; Hollow walls; Hollow walls of solid units; Masonry; Masonry walls; Reinforced concrete; Rubble

stone; Stone walls; Veneered masonry walls. Walls, bearing: Definition... -- 10 Framing over openings 30,70 In incombustible construction 11 Interior, considered partitions 25

Interior, fire resistance of 11 Jambs. .. . 30

Thickness _ .- — 22,26 Veneering not part of thickness- . -. 24 Walls, cavity... .. 23 Bond - - 23 Chases and recesses in - - 25

Definition .. . . 10 Flashing - 23 Height. - .- 23 Lateral support 22 Mortar for 21 Reinforcement... --. . -.. 23 Thickness — _ 23 Tie rods for..-. 23 Ties for wall openings 23

Walls, common-property-line:

Definition 10

Fire resistance of 11, 12

In Exterior-Protected construction 12

In fireproof construction H

In incombustible construction H

In Wood-Frame construction.. _-_ _- 12

Walls, enclosure: Definition - 10 Reinforced concrete. 26 Thickness ..- 26 Walls, exterior -- 29,70

Fire resistance of 11,12 Fire^topping — 35 Framing - 32

In Exterior-Protected construction -- 11 In incombustible construction H

In Wood-Frame construction 12 Mortar for 21 Walls, foundation. See Foundation walls. Walls, load-bearing, mortar for. 21 Walls, nonbearing:

Definition H

Thickness 22,23

Walls, panel. See Walls, enclosure. Walls, parapet — 24 Height 24

Thickness

Walls, party. See Party walls. Walls, spandrel 24

Definition 11 Thickness 24 Walls of hollow masonry units 22 Bond 22 Chases and recesses in Decrease in thickness 22 Thickness 22

Walls of hollow units, lateral support 22

Warm-air ducts: Clearances from combustible construction 40, 41 Coverings for 40,41 MateriaL 40

Protection 40 Water heaters, gas: Flue area 38 Venting 42 Water pipes, suspension of_-i 33 Water systems, private : 8, 44

Water-closet compartments:

Glass area of windows 14 Light and ventilation 13 Openable area of windows 14

Skylights in 13 Windows in 13 Water-closets, required 43 Waterproofing: Foundation walls 20 Masonry veneer 29^ Stucco 30 Welding, field 28 Source of specification 45 Wet ground, fotmdation wall vents 33 Width:

Of exit doorways - 16 Of exits, modification of 17 Of public hallways 17 See also specific topic.

[85]
Page

"Wind loads 18 Anchorage - --- 18 Increased stresses for 29 Methods of resisting 22 Source of information 45 Unit loads - 18 "Winders prohibited -- 16 IVindows - 14,44 Arrangement - 14 Distance from ceiling _-- 14 Flashing over 33 For exit stairways 16 Glass area — 14,44 In bathrooms 13 In habitable rooms - - 13 In water-closet compartments 13 Location 45 Openable area _ - 14,16 Screening of 44

Sills, not court obstructions - - - - _ 15

Sills, not yard obstructions 15 Support of beams over 32 To open on open space - 14 "Wiring _-_ - 43 Inspection. __ _ 43 Source of code - 75 Wood:

Blocking for joists --- --- -- 30 Centering, of fireplaces, removal of 39 Closeness to ground - - 33 Cutting of treated - _- 33 Debris, removal of 33 Decay-resistant species.. - - 72 Embedded in masonry or concrete _- 33 Footings 19 Not to contact soil --- 33

Piles --- - 19

Piles, driving of --- 19

Piles, load-test data - 19 Preservative treatment 19,33 Preservative treatment, information source 45 Shingles 74 Support of masonry prohibited 26 Wood construction 28,45 Concrete bases for - 33 Decay prevention... 33,71 Design... - 28,45 Firestopping 35 Floors..-. 30 Framing over openings. 30 Girders 30

Interior partitions 30

Joists 30 Masonryveneer..- 29 Plank-and-beam construction _. 32, 70 Plates 30 Ribbon boards 30 Roofs 30 Sheathing for platform framing 29

Stress tables.

-

46-69 Stucco 29,70 Termites, protection against 29, 33

Wood construction—Continued. Page

Wood houses with plywood coverings... 32 Working stresses 29, 45, 46 Wood-Frame construction 12 Area limitations 13 Height limitation 12 Wood Handbook, source of 45 Wood houses with plywood coverings 32 Fastenings of structural members 33 Wood members:

Grading of..._ . 29 Nailing 28 Posts _ _ 29 Quality. 28

Sizes 28

Sizes, information on

_

. 45

Splicing . 29 Strength 28 Woodwork, insulation of porches, steps, and terraces from 33 Working stresses 18 Arches 25 Bearing, for steel ._ _. 28 Bending, for steel ___ .... 27 Cast steel 28 Compression, for steel 27 For light steel construction ___ 28 For steel and iron 27,28 In flat panels 71 In flat panels with stressed coverings... 71 In framing over openings 70 In notched joists 31 In reinforced concrete.. 27 Increase prohibited. 8 Increased, for joints 29 Increased, for joists 29 Increased, for reinforced concrete 27 Increased , for wind loads __ 29

Increases in 18 Shearing, for steel 28 Tension, for steel 27 Wood construction 29,45,46 Workmanship.. 17 Y

Yards. _ 14 Area of _ 14 Dimensions 14 Front, definition.- 11 Rear, definition-. -- 11 Rear, depth 14 Rear, of irregular shape— - 14 Rear, required 14 Side, definition 11 Side, of irregular shape 14

Side, width 14 To be unobstructed 15

Z

Zoning requirements, not modified 34 Zoning restrictions 12 Washington, April 23, 1942.

o

[86]
BUILDING MATERIALS AND STRUCTURES REPORTS

[Continued from cover page ii] BMS32 Structural Properties of Two Brick-Concrete-Block Wall Constructions and a Concrete- Block Wall Construction Sponsored by the National Concrete Masonry Association, 10^ BMS33 Plastic Calking Materials 10^ BMS34 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 1 10^ BMS35 Stability of Sheathing Papers as Determined by Accelerated Aging 10^ BMS36 Structural Properties of Wood-Frame Wall, Partition, Floor, and Roof Constructions with

"Red Stripe" Lath Sponsored by The Weston Paper and Manufacturing Co 10^ BMS37 Structural Properties of "Palisade Homes" Constructions for Walls, Partitions, and

Floors, Sponsored by Palisade Homes 10^ BMS38 Structural Properties of Two "Dunstone" Wall Constructions Sponsored by the W. E. Dunn Manufacturing Co lOjS BMS39 Structural Properties of a Wall Construction of "Pfeifer Units" Sponsored by the Wisconsin Units Co lOjS BMS40 Structural Properties of a Wall Construction of "Knap Concrete Wall Units" Sponsored

by Knap America, Inc 10(S BMS41 Effect of Heating and Cooling on the Permeability of Masonry Walls 100 BMS42 Structural Properties of Wood-Frame Wall and Partition Constructions with "Celotex"

Insulating Boards Sponsored by The Celotex Corporation 15(4 BMS43 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 2 10^ BMS44 Surface Treatment of Steel Prior to Painting 10^ BMS45 Air Infiltration Through Windows lOf

BMS46 Structural Properties of "Scot-Bilt" Prefabricated Sheet-Steel Constructions for Walls,

Floors, and Roofs Sponsored by The Globe-Wernicke Co 100 BMS47 Structural Properties of Prefabricated Wood-Frame Constructions for Walls, Partitions, and Floors Sponsored by American Houses, Inc 100 BMS48 Structural Properties of "Precision-Built" Frame Wall and Partition Constructions

Sponsored by the Homasote Co 100 BMS49 Metallic Roofing for Low-Cost House Construction 100 BMS50 Stability of Fiber Building Boards as Determined by Accelerated Aging 100 BMS51 Structural Properties of "Tilecrete Type A" Floor Construction Sponsored by the

Tilecrete Co 100 BMS52 Effect of Ceiling Insulation Upon Summer Comfort 100 BMS53 Structural Properties of a Masonry Wall Construction of "Munlock Dry Wall Brick"

Sponsored by the Munlock Engineering Co 100 BMS54 Effect of Soot on the Rating of an Oil-Fired Heating Boiler 100 BMS55 Effects of Wetting and Drying on the Permeability of Masonry Walls 100 BMS56 A Survey of Humidities in Residences 100 BMS57 Roofing in the United States—Results of a Questionnaire 100 BMS58 Strength of Soft-Soldered Joints in Copper Tubing 100 BMS59 Properties of Adhesives for Floor Coverings 100 BMS60 Strength, Absorption, and Resistance to Laboratory Freezing and Thawing of Building

Bricks Produced in the United States 150 BMS61 Structural Properties of Two Nonreinforced Monolithic Concrete Wall Constructions 100 BMS62 Structural Properties of a Precast Joist Concrete Floor Construction Sponsored by the Portland Cement Association 100 BMS63 Moisture Condensation in Building Walls 100 BMS64 Solar Heating of Various Surfaces 100 BMS65 Methods of Estimating Loads in Plumbing Systems 100 BMS66 Plumbing Manual , 200 BMS67 Structural Properties of "Mu-Steel" Prefabricated Sheet-Steel Constructions for Walls,

Partitions, Floors, and Roofs Sponsored by Herman A. Mugler 150 BMS68 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 3 150 BMS69 Stability of Fiber Sheathing Boards as Determined by Accelerated Aging 100 BMS70 Asphalt-Prepared Roll Roofings and Shingles 150 BMS71 Fire Tests of Wood- and Metal-Framed Partitions 100 BMS72 Structural Properties of "Precision-Built, Jr." Prefabricated Wood-Frame Wall Construction Sponsored by the Homasote Co 100 BMS73 Indentation Characteristics of Floor Coverings 100 BMS74 Structural and Heat-Transfer Properties of "U. S. S. Panelbilt" Prefabricated SheetSteel Constructions for Walls, Partitions, and Roofs Sponsored by the Tennessee

Coal, Iron & Railroad Co 1 150 BMS75 Survey of Roofing Materials in the North Central States 150 BMS76 Effect of Outdoor Exposure on the Water Permeability of Masonry Walls 150 BMS77 Properties and Performance of Fiber Tile Boards , 100 BMS78 Structural, Heat-Transfer, and Water-Permeability Properties of Five Earth-Wall Constructions 200 BMS79 Water-Distributing Systems for Buildings 150 BMS80 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 4 150 BMS81 Field Inspectors' Check List for Building Constructions (cloth cover, 5 x 7H inches) — 200 BMS82 Water Permeability of WaUs Built of Masonry Units 200 -

[List continued on cover page iv]
BUILDING MATERIALS AND STRUCTURES REPORTS

[Continued from cover page iii] BMS83 Strength of Sleeve Joints in Copper Tubing Made With Various Lead-Base Solders 100 BMS84 Survey of Roofing Materials in the South Central States 15^ BMS85 Dimensional Changes of Floor Coverings with Changes of Relative Humidity and

Temperature 10(S BMS86 Structural, Heat-Transfer, and Water-Permeability Properties of "Speedbrik"" Wall

Construction Sponsored by the General Shale Products Corporation 15^ BMS87 A Method for Developing Specifications for Building Construction 10(4 BMS88 Recommended Building Code Requirements for New Dwelling Construction With

Special Reference to War Housing 20)4 BMS89 Structural Properties of "Precision-Built, Jr." (Second Construction) Prefabricated Wood-Frame Wall Construction Sponsored by the Homasote Co 15(5 BMS90 Structural Properties of "PHC" Prefabricated Wood-Frame Constructions for Walls,

Floors, and Roofs Sponsored by the PHC Housing Corporation 15(S BMS91 A Glossary of Housing Terms 15(5