The program of research on building materials and structures carried on by the

National Bureau of Standards was undertaken with the assistance of the Central Housing Committee, an informal organization of governmental agencies concerned with

housing construction and finance, which is cooperating in the investigations through a committee of principal technicians.

CENTKAL HOUSING COMMITTEE

ON KESEARCH, DESIGN, AND CONSTRUCTION

A. C. Shire, Chairman. Howard P. Vermilya, Vice Chairman.

United States Housing Authority. Federal Housing Administration.

Sterling R. March, Secretary.

Mary F. Taylor, Assistant Secretary.

Pierre Blouke, John S. Donovan,

Federal Home Loan Bank Board. Farm Security Administration.

Hugh L. Dryden, George W. Trayer,

National Bureau of Standards. Forest Service (F. P. Laboratory).

Louis A. Simon, Rollo H. Britten,

Pubhc Buildings Administration. Public Health Service.

Luther M. Leisenring, George E. Knox,

Construction Division (War). Yards and Docks (Navy).

Edward A. Poynton, William R. Talbott,

Office of Indian Affairs. Veterans' Administration.

Wallace Ashby,

Bureau of Agricultural Chemistry and Engineering.

NATIONAL BUREAU OF STANDARDS

STAFF COMMITTEE ON ADMINISTRATION AND COORDINATION

Hugh L. Dryden, Chairman.

Mechanics and Sound.

Phaon H. Bates, Gustav E. F. Lundell,

Clay and SUicate Products. Chemistry.

Hobart C. Dickinson, Addams S. McAllister,

Heat and Power. Codes and Specifications.

Warren E. Emley, Henry S. Rawdon,

Organic and Fibrous Materials. Metallurgy.

The Forest Products Laboratory of the Forest Service is cooperating with both

committees on investigations of wood constructions.

[For list of BMS publications and directions for purchasing, see 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 BMS72

Structural Properties of "Precision-Built, Jr."

Prefabricated Wood-Frame Wall Construction

Sponsored by the Homasote Co.

by ARCHIE H. EASTON and MAHLON F. PECK

with the collaboratioyi of

R. F. LUXFORD

Forest Products Laboratory

Forest Service, United States Department ot Agriculture

ISSUED APRIL 14, 1941

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

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

UNITED

FOR S A L F.

STATES GOVERNMENT PRINTING

BY THE SUPERINTENDENT OF DOCUMENTS,

OFFICE • WASHINGTON • I94I

WASHINGTON, D. C. • PRICE TO CENTS
Foreword

This report, is one of a series issued by the National Bureau of Standards on the

structui'al properties of constructions intended for low-cost houses and apartments.

These constructions were sponsored by organizations within the building industry advocating and promoting their use. The sponsor built and submitted the specimens

described in this report for participation in the program outlined in BMS2, Methods of Determining the Structin-al Properties of Low-cost House Constructions. The sponsor,

therefore, is responsible foi' the design of the constructions and for the description of materials and method of fabrication. The B\ireau is responsible for the testing of the

specimens and the preparation of the report.

This report covers only the load-deformation relations and sti'ength of the structural

element submitted when subjected to compressive, transverse, concentrated, impact,

and racking loads by standardized methods simulating the loads to which the element

would be subjected in actual service.

The Forest Products Laboratory, Forest Service, United States Department of Agriculture, collaborated in the tests of those constructions which had wood structural

members.

The National Bureau of Standards does not "approve" a construction, nor does it express an opinion as to its merits for reasons given in reports BMSl and BMS2. The

technical facts presented in this series provide the basic data from which architects and

engineers can determine whether a construction meets desired performance requirements.

Lyman J. Briggs, Director.

[II]
Structural Properties of "Precision-Built, Jr." Prefabricated WoodFrame Wall Construction Sponsored by the Homasote Co.

by ARCHIE H. EASTON and MAHLON F. PECK

with Ihc culliihoration of

R. F. LUXIORD

Forest Products Laboratory, Forest Service, United States Department of Agriculture

C O N T E :N T S

Page Foreword ii

r. Introduction 1

II. Sponsor and jjroduct 2

III. Specimens and tests 2

IV. Materials

1. Wood

2. Insulating fiberboard

3. Nails

4. Glue

V. Wall DK

1. Sponsor's statement

(a) Four-foot wall specimens.

Pago

V. Wall DZf^Continued,

1. Sponsor's statement—Continued.

(b) Eight-foot wall specimens 7

(c) Comments 9

2. Comjjressive load 9

3. Transverse load 9

4. Concentrated load 11

5. Impact load 11

6. Racking load 11

VT. Adflitioiial comments by sponsor. 12

VII. Selected references 14

ABSTRACT

For the program on the determination of the structural properties of low-cost house constructions, the Homasote Co., Trenton, N. J., submitted 12 specimens

rejjresenting a wall construction consisting of a wood

frame with "Homasote" insulating fiberboard on both

faces. The specimens were subjected to compressive, transverse, concentrated, impact, and racking loads; for each

load three like specimens were tested. The deformation

under load and the set after the load was removed were measured for uniform increments of load. The results are presented in graphs and in a table.

I. INTRODUCTION

To provide technical facts on the performance

of constructions for low-cost houses, to discover

promising new constructions, and ultimately to determine the properties necessary for acceptable performance in actual service, the National

Biu-eau of Standards has in vited the cooperation

of the building industry in a program of research on building materials and structures suitable

for low-cost houses and apartments. The objectives of this program are described in BMSl,

Kesearch on Building Materials and Structures

for Use in Low-Cost Housing.

To determine the strength of house constructions in the laboratory, standardized methods

were developed for applying loads sinmlating

the loads to which a completed house is subjected. Included in this study were masonry

and wood constructions of types which have

been extensively used in this country for houses

and whose behavior under widely different

service conditions is well known to builders and

the public. Tlie reports on these constructions

are BMS5, Structural Properties of Six Masonry

Wall Constructions, and BMS25, Structural

Properties of Conventional Wood-Frame Constructions for Walls, Partitions, Floors, and

Roofs. The masonry specimens were built by

the Masonry Construction Section of this Bureau, and the wood-frame specimens were built

and tested by the Forest Products Laboratory

at Madison, Wis.

The present report describes the structural

]3roperties of one element of a house sponsored

by one of the manufacturers in the building

301517°—41 [1]
industry. The wall specimens were subjected

to compressive, transverse, concentrated, impact, and racking loads, simulating the loads to which the walls of a house are subjected. In

actual service compressive loads on the walls

of a one-story house are produced by the weight

of the roof and by snow and wind loads; trans- verse loads are produced by wind, concentrated

and impact loads by accidental contact with

heavy objects, and racking loads by the action

of the wind on the adjoining walls. The deflection and set under each increment

of load were measured, because the suitability

of a construction depends not only on its re- sistance to deformation when loads are applied

but also on its ability to return to its original

size and shape when the loads are removed.

II. SPONSOR AND PRODUCT

BMS48, Structural Properties of "PrecisionBuilt" Frame Wall and Partition Constructions

Sponsored by the Homasote Co., reports the

results on its Standard "Precision-Built" construction. The present report gives the results on the "Precision-Built, Ji." construction

sponsored by the same organization.

The wall construction consists of a lightweight

wood frame with "Homasote" insulating fiber- board fastened to each face by glue and nails.

III. SPECIMENS AND TESTS

The wall construction was assigned the

symbol DK and the individual specimens were

assigned the designations given in table 1.

Table 1.

Specimen designations, wall DK

Specimen designation

CI, C2, CS..

Tl, T2. T3.

PI, P2, PS.

II, 12, IS.... Bl. R2, R3..

Load

Compressive. - Transverse Concentrated Impact

Racking

Load applied

Upper end. Either face. Do.

Do. Near upper end.

" The concentrated and impact loads were applied to the same speci- mens, the concentrated loads first. Except as mentioned below, the specimens were tested in accordance with BMS2, which

report also gives the requirements for the

specimens and describes the presentation of the

results of the tests, particularly the loaddeformation graphs.

For the transverse and impact loads there

were only three specimens, not six as stated in BMS2, because the specimens were symmetrical

about a vertical plane midway between the

faces, and the results for transverse and impact

loads applied to one face should be identical with

those applied to the other face. For the same

reason the concentrated load was applied to only three specimens. The differences in the

nails in the inside face and the oiitside face were

so small that the constructions were considered

symmetrical.

Under compressive load, the shortening of the

entire specimen may not be proportional to the

value obtained from the compressometers at- tached to the specimen over only a portion of its height; therefore, the shortenings and the sets were measured with compressometers attached

to the plates through which the load was

applied, not attached to the specimen as described in BMS2.

The lateral deflections under compressive

loads were measured with a deflectometer of fixed

gage length, which consisted of a light (duralumin) tubular frame having a leg at one end and

a hinged plate at the other. The deflectometer

in a vertical position was attached to the specimen by clamping the hinged plate near the

upper end to one of the faces. The gage length

(distance between the points of support) was 7

ft. 6 in. A dial micrometer was mounted on

the frame at midlength, with the spindle in contact with the wall specimen. The dial was

graduated to 0.001 in., and the readings were

recorded to the nearest division. There were two deflectometers on the specimen, one near each outer stud. This method of measurement

was used instead of the taut-wire mirror-scale

method described in BMS2.

The indentation inider concentrated load and

the set after the load was removed were measured, not the set only as described in BMS2.

The apparatus is sho^vn in figure 1. The load was applied to the steel disk. A, to which the crossbar, B, was rigidly attached.

The load was measured by means of the spring

dynamometer, C. Two stands, D, rested on

the face of the specimen, each supporting a dial micrometer, E, the spindle of which was in contact with the crossbar 8 in. from the center

of the disk. The micrometers were graduated

to 0.001 in., and readings were recorded to the

[2]
FiGUKE 1.

Apparatus for concentrated-load test.

A. stool ijisk: B. omssbar: C, spring dynamomoter; D. stand: E, dial mioroniotor.

nearest division. The initial reading (average

of tlie micrometer readings) was observed under

the initial load, which included the weight of the disk and dynamometer. A load was applied to the disk, and the average of these

micrometer readings minus the initial reading was taken as the depth of the indentation under

load. The deflections and sets under the impact

loads were measured by means of two deflectometers and two set gages, not one of each as described in BMS2. The deflectometers were

placed in contact with the unloaded face of the

specimen at midspan, one under each outside

stud, and the set gages rested on the loaded

face, one over each outside stud. The readings,

therefore, were not affected by local deformation of the fiberboard.

The deformations under racking loatl were measured with a right-angle deformeter, consisting of a steel channel and a steel angle braced

to form a rigid connection. In use, the channel of the deformeter supported by two steel blocks, Yi in. thick, 4 in. square, rested along the

top of the specimen, with the steel angle ex- tending downward in the plane of the specimen.

Two pins passed snugly through the web of the channel into the top plate of the specimen.

The floor plate was in contact with a steel stop.

A dial micrometer was attached to the steel stop and the spindle was in contact with the

steel angle of the deformeter. The gage length

(distance from the top of the specimen to the center of the steel stop) was 7 ft. IO/4 in. The

micrometer was graduated to 0.001 in., and

readings were recorded to the nearest division.

The deformeter was used instead of the taut- wire mirror-scale device described in BMS2.

The tests were begun July 30, 1940 and completed August 2, 1940. The sponsor's repre- sentative witnessed the tests.

IV. MATERIALS

Unless otherwise stated, the information on

materials was obtained from the sponsor and

from inspection of the specimens. The Forest Products Laboratory identified the species of the wood in the framing. The Paper Section

of this Bureau determined the physical properties of the fiberboard, and the Engineering

Mechanics Section determined the moisture

content of the wood and fiberboard.

[3]
1. Wood

Framing.—The framing- was identified as Douglas fir, Pscudotsuga taxijolia, No. 1 common. Sizes, 1% by 1% in. (nominal 2 by 2 in),

S2S1E (sm-faced two sides and one edge),

and Wi by 2% in. (nominal 2 by 3 in), S4S

(surfaced four sides)

Spacer blocks. —Identified as ponderosa pine,

Pinus po7iderosa, No. 2 common, by 1% in. (nominal 1 by 2 in), S4S.

After each specimen was tested, one face was

removed to expose the framing and a sample

Figure 2.— Wall DK.

Tyjiical 4-ft wall specimen.

cut from the studs for identification of the

species. Photographs were made of each

specimen showing the quality of the wood.

Figures 2 and 3 are typical specimens.

For each specimen, readings were taken with an electric moisture meter on each piece of framing and on two spacer blocks. To calibrate

the moisture meter, moisture determinations were made on two pieces of framing and one

spacer block from each specimen by drying

them to constant weight at 212° F. From

these determinations the correction to be added

algebraically to the meter readings was —1.0

for framing and +0.4 for spacer blocks. Values

of the moisture content given in table 2 were

obtained by applying these corrections to the

average of the meter readings and rounding the

results to the nearest whole percent.

Table 2.Moisture content of the wood

[Determined the day the wall specimen was tested]

Material

Moisture content »

Mini- mum

Maxi- mum Average

Framing, Douglas fir Spacer blocks, ponderosa pine

Percent

10

7

Percent

14

11

Percent

12

9

» Based on the weight when oven-dry.

2. Insulating Fiberboard

The insulating fiberboard was "Homasote",

15/32 in. thick, made from vegetable fibers derived largely from waste paper. The fibers are sized with rosin and waxes to increase water

resistance and then felted into boards.

The physical properties, given in table 3, wer(> determined on undamaged samples taken

from the wall specimens after testing. The

linear (expansion, tensile strength, transverse strength and deflection, and water absorption were determined in accordance with Federal

Specification LLL-F-321a, Fiberboard; Insulating. For these properties the board complied with the requirements for class A. The

thermal conductivity failed to comply with the

requirements for class A, for which the maximum value IS 0.36 (Btu/hr ft^')/("F/in).

[4]
FiGUBK 3.— Wall DK.

Typical s-ft wall specimen.

Table 3.Physical -properties of insidaimq hoard, 15/32 in. thick

[The samples were taken from the specimens after they had been testeil]

Property

Tensile strength: Machine direct ion lb/in.

Cross direction lb/in.

Transverse strength: » Machine direction lb- Cross direction lb- Deflection at rupture: Machine direction in- Cross direction in- Linear expansion for 45 percent change in relative humidity

percent

Nail-holding strength: Lateral lb. Density, after drying 24 hours at 160° F lb/ft s Moisture content, based on weight when oven-dry.... percent

.\ir permeability (ft.s/hr. ft.2)/(lb./in.2). Water absorption, bv volume percent. Thermal conductivity (Btu./hr, ft.2)/(''F/in.)

" Span, 12 in.; width of specimens, i in. Value given by sponsor.

Value

043

()27

iS33

0. 85 .72

. 20

143 25.6

925

4. 1 b 0.41

The moisture coiitont of the fiberboard was

determined on one sample from each w^all speci- men by drying at 212° F mitil the weight was

constant.

3. Nails

Steel. - A description of the steel-wire nails

is given in table 4.

Table 4.Description of steel-wire nails

Type Size Length

Steel- Wire Gage

Diameter Finish

Nails

per pound

Common... Do

Penny

1020

4

in.3

4m

Nn.

9

6

14

in.

0. 1483

. 192 .080

Bright

-do

69

31 Box Zinc-coated 403

[5]
iVlovel metal. —The monel-metal nails, 1% in. long, were made from monel-metal wire, 0.083-

in. diam; finish, bright; number of nails per

pound, 330. To increase the force required to pull the nails from the wood, there were 24

annular barbs per inch of length between the

head and the diamond ]ioint.

4. Glue

Casein glue, grade A, ground. Formula:

casein, 65 percent; lime, 15 percent; and dis- persing agents and secret ingredients. One

part of glue was mixed with one part of water,

by volume, to which were added 2 ounces of kerosene per pound of dry glue. The glue

complied with United States Army SpecificaFiGUBE 4.

Four-foot wall specimen DK.

A, studs; B, floor plate; C, top plate; D, outside face; E, inside face; F. spacer block.

tion 3-152-A and United States Navy S]jecitication 52G8b. I. F. Laucks, Inc., "Lauxein

888."

V. WALL DK

1. Sponsor's Statement

Wall DK was a wood-frame construction

having insulating fiberboaxd on both faces,

fastened by glue and nails. The specimens were not painted.

The price of this construction in Washington,

D. C, as of July 1937, was $0.17/ft2.

(a) Four-Foot Wall Specimens

The 4-ft wall specimens, shown in figure 4, were 8 ft 0 in. high, 4 ft 0 in. wide, and 2%6 in. thick. Each was a wood frame to which the

faces were fastened. The frame consisted of four

studs. A, fastened to floor plate, B, and top

plnte, C. Both the outside face, D, and the

inside face, E, consisted of one sheet of insulating fiberboard. The edges of the faces were

connected by spacer blocks, F.

Studio. —The studs. A, were Douglas fir, 1%

by 1^^ in. (nominal 2 by 2 in), 7 ft 8 in. long,

spaced 1 ft 0 in. Except in specimens DK T3

and DK-I2, each stud was fastened to the floor plate and top plate by one 20d common nail through the plates into the stud (not toenailed). In specimens DK-T3 and DK-I2 the studs were

fastened to the floor plate and top plate by two

lOd common nails, one through each edge of the

stud and into the plates (toenailed). In houses

of this construction there is one 16d common

nail through the plate and into the stud. Floor plate and top plate. —Both floor plate, /i, and top plate, C, were Douglas fir, Ifa by 2% in. (nominal 2 by 3 in), 4 ft 0 in. long. The upper

surface of the floor plate and the lower surface

of the top plate were dadoed (notched) % by

1% in., 12 in. on centers. The ends of the studs

fitted into the notches.

Faces. —Each face was one piece of fiberboard,

in. thick, 8 ft 0 in. high, and 4 ft 0 in. wide,

fastened to the floor plate, top plate, and studs

by both glue and nails. The glue was liberally

applied to the studs and the plates by a roller continuously supplied with glue. The nails were spaced 6 in. along the floor plate and top

[6]
Figure 5.

Eighi-fool wall specimen DK.

A, sdids; B. floor plate; C, top plate; I), outside face; E, Inside face.

plate aii(] IVoiii (i to 10 in. alony,' ciich stiul. 'I'lic nails fastoiiinfz- tlie inside face were inonel

metal, 1% in. long, 0.083-in. diam, and those

fastening the outside face were 4d zinc-coatetl

box nails. The nails along the plates were from

% in. to 1 in. from the ends of the board.

Spacer- blocks.—The spacer blocks, f\ were

ponderosa pine, % by 1% in., 2% in. long,

spaced 1 ft 0 in. Each block was fastened to each face by two 4d zinc-coated nails through

the fiberboard and into the block.

(6) Eig/d-Fooi Wall Specimens

The 8-ft wall specimens, shown in figure 5, were 8 ft 0 in. high, 8 ft 1% iri. wide, and 2?{6 in. thick. The specimens were similar to the 4-ft specimens except that there were nine studs

spaced 1 ft 0 in. on centers and no spacer

blocks.

/'act\s.— Each face was one piece of fiber- board, ^Yzi hi. thick, 8 ft 0 in. high, 8 ft 1^^ in. wide, fastened to the floor plate, top plate, and

[7]
Table 5.

Structural properties of wall DK

[Weight, based on face area: 3.13 Ib/ft^]

Coinjjressive load » Transverse load; span 7 ft

(i in.

1 Concentrated load >•

1 I'"'^^''* ^''f-'

' "

j b in. Racking load

Specimen

Maxi- mum

load Specimen

Maxi- mum

load

Iblp-124

113 118

Specimen

Maxi- mum

load Specimen

Maxi- mum

heieht of drop

Specimen

Maxi- mum

load

Cl

i Kips/ft

2. 82

3. 06 2.70

Tl - PI

lb 267

260

269

11 --- n

5.0

5. 5 5.0 m

<i Kipslft

1.15 1.72

1.40 C2 T2 P2 12 R2

CS TS PS IS RS. Average 2.86 Average.- 118 Average . 265 Average. .. . .5.2 .Average.. 1.42

" The compressive loads were applied (t.M in. (one-third the thickness of the frame) from the face of the studs nearer the load line,

b Diameter of steel disk, 1 in.

' Weight of sandbag, 601b.

<l A kip is 1 ,000 lb

studs by both ghie and nails. On the inside

face the nails into the studs were monel metal,

lYi in. long, 0.083-in. diam, spaced from 6 to 10

in., and those into the plates 4d zinc-coated box

nails spaced 6 in. On the outside face the

nails were 4d zinc-coated box nails spaced

from 6 to 10 in. in the studs and 6 in. in the

]jlates. All nails in the floor plate, top plate,

and edge studs were from K to 1 in. from the

edge of the fiberboard.

Z5

^ 2.0

/.O

I

0

1

OCf -o

f

FiGUKE 6. —Wall specimen DK-C3 under compressive

load. A, deflectomcter; B, compressometers.

.OS ./O ./5

s/yor/en/ng /n.j8ff

Figure 7.Compressive load on ivall DK.

Load-shortening (open circles) and load-set (solid circles) results for specimens DK-Cl. C2. and CS. Load applied 0..'54 in. (one-third the thickness of the frame) from the face of the studs nearer the load line. The loads are in kips per foot of actual width of specimen.

[8]
0 02 0.4 0.6 /otero/ c/ef/ec//on /n. Figure 8. —Co inprcssive load on wall DK.

Loaii-lateral deflection (open circles) and load-lateral set (solid circles) results for specimens DK-Ci, CS, and CS. Load applied 0.54 in. (onethird the thickness of the frame) from the face of the studs nearer the

load line. The loads are in kips i)er foot of actual width of s|)ecimen. The deflections and sets are for a gage length of 7 ft G in., the gage length

of the deflectometers.

(c) Comments

Walls are built in sections, one section for each side of the room. The maximum witlth of section available is 20 ft; however, there should

be no width greater than 16 ft unsupported by a

ptirtition . 11 tiie room dimensions ur(^ greater

than 14 ft (the maximum width of Ilomasote

iiberboard), a strij) of Vehisote fiberboa,r(l , )^ in. thick, is nailed or glued over tiie joints in the

iTiside face. The studs and ])lntes are pi'ccut and then

assembled on a jig table.

2. CoisiPRESHivE Load

Wall specimen DK-C3 under compressive

load is shown in figure 6. The results for speci- mens DK-Cl, C2, and C3 are given in table 5 and in figures 7 and 8. The speed of the movable head of the testing

machine was adjusted to 0.072 in./min. The

gage length of the compressometers was 8 ft 0 in. Under the maximum load on each specimen,

the studs buckled laterally toward the outside

face (the face farther from the load line). No

other effects were observed except that one

outer stud in specimen CS split longitudinally near one end.

3. Transverse Load

Specimen DK-T2 under transverse load is shown in figure 9. The results are presented

m table 5 and figure 10. The transverse loads were applied to the outside face (fastened with glue and 4d box nails)

Figure 9.—Wall specimen DK~T2 under transverse load.

[9]
Figure 10.

/ Z 5

c^ef/ecf/o/7 /n,

-Transverse load on wall UK.

Z80

240

\5 ZOO

s. ^60

I^ /ZD

\

I 30

40'

— / ••

/

/

1

1

1

1

17]

LJ

Tj

7

Load-ik'Ik'Ction (opi'n oirclcs) and load-sot (solid circles) results for spec- imens DK-Tl . TS, and TSon the span 7 ft R in. The load (i)ounds per

siiuare foot) is the total load divided by the product of the span and

the width of specimen.

^ 0 0/ aZ OJ 0,4- 0.5 /nc/en/a//on /n. Figure 11.

Concentrated load on wall DK.

Load-indentation (open circles) and load-set (solid circles) results for specimens DK-PI, Pi, and PS.

Figure 12. — Wall specimen DK—I2

during the impact tests. A. deflectomctcr; B, set gage.

[10]
5

4

I

0

•

/

o

/•

I1

OCX)

1•

1

'o

1 •

1

1•

1

0 a

1 / 0/23

a'ef/ec//on /n. Figure 13.

Impact load on wall DK.

Height of drop-deflection (open circles) and height of drop-set (solid

circles') results for specimens DK-Il. 11. and IS on the span 7 ft (i in.

of specimen DK-Tl and the inside face (fastened with glue and monel-metal nails) of speci- mens T2 and T3. The speed of the movable

head of the testing machine was adjusted to

0.31 in./min. In specimen Tl under a load of 121 lb/ft- an

outer stud cracked at a knot near midspan.

Under the maximum load this stud broke, rupturing the fiberboard locally; also an inner stud

and the other outer stud ruptured near a loading

roller. In specimens and T3 at loads of 102

and 109 Ib/ft^, respectively, the glue bond ruptured on the loaded face between the loadingrollers; at 106 and 117 Ib/ft^, respectively, a crack appeared in an outer stud under a loading

roller. Under the maximum load on T2, an umer stud cracked under a loading roUer. Under the maximum load on T3, all studs either

cracked or ruptured.

4. Concentrated Load

Specimen DK Pi under concentrated load

is sho^v^l in figure 1. The results for specimens

DK-Pl, P2, and PS are given in table 5 and in figm-e 11. The concentrated loads were applied to the

fiberboard midway between two adjacent studs,

1 ft 6 in. fi-om the end of the specimen. The

diameter of the disk was 1 in. Under the max- imum load on each specimen, the disk punclied

through the fiberboard.

5. Impact Load

Specimen DK-I2 during the iinpact load is shown in figure 12. The results for si)e('imens

DK-Il, 12, and 13 are given in table 5 and in figure 13. The impact loads were applied to the outside

face (fastened with glue and 4d box nails) of DK-Il and to the inside face (fastened with

glue and monel-metal nails) of specimens 12 and

13, the sandbag (weight, 60 lb) striking the center of the specimen on the fiberboard between two studs. In specimens II and 12 the fibeiboard on the

face struck cracked under the sandbag at a drop of 3.0 ft. At a drop of 3.5 ft the sandbag

broke through the fiberboard on the face struck

of both specimens. After a drop of 4.5 ft on II , the fiberboard separated from the inner stuils on the face not struck. At the maximum drop

the sandbag went through the face not struck

and one outei- stud broke at midspan. After

the maximum drop on 12, the fiberboard on the

face not struck was broken and some of the 4d

box nails had pulled out of the studs. After a drop of 3.0 ft on 13, the fiberboard was broken

under the bag on the face struck. At a drop of 4.0 ft the box nails began to pull out of the studs on the face not struck. At the maximum drop

the bag broke the fiberboard and separated it from two of the studs on the face not struck.

6. Racking Load

Specimen DK R2 under racking load is shown in figure 14. The results on specimens

DK-Rl, R2, and R3 are given in table 5 and

figure 15. The racking loads were applied to the top

plate, and the stop was in contact with the

floor plate at the diagonally opposite corner. Under the maximum load on specimen Rl,

the top plate crushed under the steel plate re- strained by the vertical tie rods. Under the

maximum load on R2, the specimen deflected

laterally 2)2 m. at the edge not loaded. In specimen R3 under the maximum load, the top

[11]
plate crushed under the steel plate restranied

by the vertical tie rods and the stud at the

loaded edge buckled outward in the plane of the

wall.

VI. ADDITIONAL COMMENTS BY

SPONSOR

The "Precision-Built, Jr." construction combines the economies derived from a maximum

of shop fabrication and the resulting reduction

in time of erection. This construction is rec- ommended by the sponsor for one-story buildings having a width up to 24 ft. The floors, walls, partitions, ceilings, and

roofs are fabricated in sections and assembled on the site. When designing a house, it is desirable to use as many sections of the same

dimensions as possible.

The framing of a typical house is shown in figure 16.

Fkihre 14.

Wall specimen DK-R£ under racking

load. A, deformeter; B, dial micrometer; C, stop.

t

/.6

/.Z

/.O

A:

5

08

0.6

04

02

0^

— —0 O—

<D

t D/C 0 0/ 02

c/eformaf/on

OJ

/n/6ff

Figure 15.

Rackmg load on wall DK.

Load-deformation (open circles) and load-set (solid circles) results for specimens DK-Rl, R2, and R3.

actual width of specimen. The loads are in kips per foot of

[12]
Figure 16.

Section of typical "Precision-Built, Jr." house.

Junior system ot construction.

Any type of foundation can be used for the

Junior construction either with or without

basement. The precast-pier type of foundation

is shown because it is beheved to be the least expensive.

Each floor section consists of a wood frame,-

insulating fiberboard, and finish flooring. The

frame has two joists (2 by 10 in) and two end

members fastened together to form a rectangle.

Parallel to the end members are transverse members (2 by 6 in.) resting on ledger members

(2 by 4 in). The largest floor section fabricated is 12 ft long by 7 ft wide.

The floor sections are secured to the foundation by bolts or lag screws through eyebolts

embedded in the concrete. Adjacent sections

are fastened by bolts, /^-in. diam, spaced 3 ft. This draws complementary edges of the tongueand-grooved finish floor together, rendering the

joint inconspicuous. The finish floor is stained

and shellacked in the shop; a final coat of varnish is applied in the field. The surface of "Homasote" is weather re- sistant; therefore the exterior need not l)e painted if low cost is desired. An oil paint

mixed with sand passing a No. 20 sieve when

[13]
applied to the exterior gives the appearance of stucco. The interior may be finished with

Rezitex or Plasterez, manufactured by I. F. Laucks, Inc. If exterior and interior finishes are requested, they are applied in the factory.

The walls are anchored to the floor by channel

clips spaced 3 to 4 ft. Exterior wall sections

are joined at the corners by four % by 3 in. lag screws. Windows are prefitted to the frames

and installed at the site. Partition sections ai-e fabricated and assembled similarly to the exterior-wall sections.

Partition sections are fastened to the floor by

channel clips and to the walls and other partitions by 20d casing nails at each intersection.

Each ceiling section consists of joists (2 by 4

in) spaced 1 ft, transverse furring strips (1 by 2

in) spaced 1 ft on the lower face of the joists,

and insulating fiberboard fastened to the furriiig

strips by glue and nails. The largest sections

fabricated are 12 ft long by 8 ft wide.

Ceiling sections are fastened together by

carriage bolts, %-in. diam, spaced 2 to 3 ft, and

to the wall and partition sections by metal

ceiling clips and by lag screws, %-in. diam, 2 in. long, spaced 4 ft. Each roof section consists of rafters (2 by 6

in.) spaced 1 ft, tied together by a ridge member

(1 by 8 in.) and at the eaves by a plate (2 by 4

in), with insulating fiberboard on the upper

face. The largest sections fabricated are 16 ft long by 8 ft wide. Roof covering is applied

after the sections are assembled.

Roof sections are fastened together along the

edge rafters and ridge member by carriage

bolts, %-in. diam, spaced 4 ft. At the eaves the

roof sections are fastened to the ceiling sections

by lag screws. Gable ends have no inside face and are made

in one section in the same way as the walls. The sections are fastened to the joists and

rafters by lag screws.

The physical properties of the fiberboard were

determined by C. G. Weber of the Paper

Section of this Bureau, under the supervision of B. W. Scribner.

The descriptions and drawings were pre- pared by E. J. Schell and G. W. Shaw of the

Building Practice and Specifications Section,

under the supervision of V. B. Phelan.

The structural properties were determined by

the Engineering Mechanics Section, under the

supervision of H. L. Whittemore, with the

assistance of the following members of the professional staff': E. S. Cohen, J. S. Noble, J. S. Rimmer, L. R. Sweetman, and H. L. Weiss.

VII. SELECTED REFERENCES

Ariny and Navy Try Out "Demountable" Houses, American Builder and Building Age 63, No. 1, 46, 47, 75 (1941). Old Newspapers to New Houses, Architectural Forum 73, No. 6, 531-534, 34-36 (1940). Washington, December 18, 1940.

[14]
BUILDING MATERIALS AND STRUCTURES REPORTS

On request, the Superintendent of Documents, U. S. Government Printing OflBce, Washington,

D. C, will place your name on a special mailing list to receive notices of new reports in this series as soon as they are issued. There will be no charge for receiving such notices. An alternative method is to deposit with the Superintendent of Documents the sum of $5.00,

with the request that the reports be sent to you as soon as issued, and that the cost thereof be charged against your deposit. This will provide for the mailing of the publications without

delay. You will be notified when the amount of your deposit has become exhausted.

If 100 copies or more of any paper are ordered at one time, a discount of 25 percent is allowed. Send all orders and remittances to the Superintendent of Documents, U. S. Government Printing

Office, Washington, D. C.

The following publications in this series are available by purchase from the Superintendent of Documents at the prices indicated:

BMSl Research on Building Materials and Structures for Use in Low-Cost Housing 10(4 BMS2 Methods of Determining the Structural Properties of Low-Cost House Constructions. _ lOfi BMS3 Suitability of Fiber Insulating Lath as a Plaster Base 10(4 BMS4 Accelerated Aging of Fiber Building Boards lOjS BMS5 Structural Properties of Six Masonry Wall Constructions 15(4 BMS6 Survey of Roofing Materials in the Southeastern States 15^ BMS7 Water Permeability of Masonry Walls 100 BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel lOji 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(4 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

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 BMS18 Structural Properties of "Pre-Fab" Constructions for Walls, Partitions, and Floors Sponsored by the Harnischfeger Corporation 100 BMS19 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 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

[List continued on cover page IV]
BUILDING MATERIALS AND STRUCTURES REPORTS

[Continued from cover page III] BMS30 Structural Properties of a Wood-Frame Wall Construction Sponsored by the Douglas

Fir Plywood Association lOji BMS31 Structural Properties of "Insulite" Wall and "Insulite" Partition Constructions Sponsored by The Insulite Co 15^ BMS32 Structural Properties of Two Brick-Concrete-Block Wall Constructions and a Concrete- Block Wall Construction Sponsored by the National Concrete Masonry Association. 10(4 j BMS33 Plastic Calking Materials lOji | BMS34 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 1 lOfi

' 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 lOji BMS37 Structural Properties of "Palisade Homes" Constructions for Walls, Partitions, and J

Floors Sponsored by Palisade Homes J

BMS38 Structural Properties of Two "Dunstone" Wall Constructions Sponsored by the W. E. M

Dunn Manufacturing Co ^^i^ S

BMS39 Structural Properties of a Wall Construction of "Pfeifer Units" Sponsored by the Wisconsin Units Co 10^ ! BMS40 Structural Properties of a Wall Construction of "Knap Concrete Wall Units" Sponsored

by Knap America Inc 10^ BMS41 Effect of Heating and Cooling on the Permeability of Masonry Walls lOji BMS42 Structural Properties of Wood-Frame Wall and Partition Constructions With "Celotex"

Insulating Boards Sponsored by The Celotex Corporation 10^ 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 10^ BMS46 Structural Properties of "Scot-Bilt" Prefabricated Sheet-Steel Constructions for Walls,

Floors, and Roofs Sponsored by The Globe-Wernicke Co 10^ BMS47 Structural Properties of Prefabricated Wood-Frame Constructions for Walls, Partitions, i and Floors Sponsored by American Houses, Inc lOji BMS48 Structural Properties of "Precision-Built" Frame Wall and Partition Constructions

Sponsored by the Homasote Co 10^ BMS49 Metallic Roofing for Low-Cost House Construction lOfi BMS50 Stability of Fiber Building Boards as Determined by Accelerated Aging 10^ BMS51 Structural Properties of "Tilecrete Type A" Floor Construction Sponsored by the Tile- crete Co 10{5

BMS52 Effect of Ceiling Insulation Upon Summer Comfort 10j5 BMS53 Structural Properties of a Masonry Wall Construction of "Munlock Dry Wall Brick"

Sponsored by the Munlock Engineering Co 10(4 BMS54 Effect of Soot on the Rating of an Oil-Fired Heating Boiler 10^ BMS55 Effects of Wetting and Drying on the Permeability of Masonry Walls 10^ BMS56 A Survey of Humidities in Residences 10(4 BMS57 Roofing in the United States—Results of a Questionnaire 10^ BMS58 Strength of Soft-Soldered Joints in Copper Tubing 10^ BMS59 Properties of Adhesives for Floor Coverings 10(4 BMS60 Strength, Absorption, and Resistance to Laboratory Freezing and Thawing of Building

Bricks Produced in the United States 15(4 BMS61 Structural Properties of Two Nonreinforced Monolithic Concrete Wall Constructions. . 10^ BMS62 Structural Properties of a Precast Joist Concrete Floor Construction Sponsored by the Portland Cement Association lOji BMS63 Moisture Condensation in Building Walls 10^ BMS64 Solar Heating of Various Surfaces 10(4 BMS65 Methods of Estimating Loads in Plumbing Systems 10(4 BMS66 Plumbing Manual 20^ BMS67 Structural Properties of "Mu-Steel" Prefabricated Sheet-Steel Constructions for Walls,

Partitions, Floors, and Roofs Sponsored by Herman A. Mugler 15^ BMS68 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 3 15fJ BMS69 Stability of Fiber Sheathing Boards as Determined by Accelerated Aging 10^ BMS70 Asphalt-Prepared Roll Roofings and Shingles 15j4 BMS72 Structural Properties of "Precision-Built, Jr." Prefabricated Wood-Frame Wall Construction Sponsored by the Homasote Co 10^