NATIONAL

BUREAU OF STANDARDS
The program of research on building materials and structures imdertaken by the

National Bureau of Standards is planned with the assistance of the following advisory

committee designated by the Subcommittee on Design and Construction of the Central

Housing Committee.

TECHNICAL RESEARCH GROUP

Walter Junge, Federal Housing Administration, Chairman

A. C. Shire, United States Housing Authority, Vice Chairman

A. G. Bear,

Veterans' Administration.

Pierre Blouke,

Home Owners' Loan Corporation.

C. W. Chamberlain,

Procurement Division. Jos. M. DallaValle,

PubHc Health Service.

Hugh L. Dryden,

National Bureau of Standards.

G. E. Knox,

Bureau of Yards and Docks, Navy

Department.

Sterling E. March, Secretary

The program is administered and coordinated by the following staff committee of

the Bureau:

Hugh L. Dryden, Chairman

P. H. Bates W. E. Emley A. S. McAllister

H. C. Dickinson G. E. F. Lundell H. S. Rawdon

The Forest Products Laboratory of the United States Department of Agriculture

is cooperating with the National Bureau of Standards in studies of wood constructions.

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Vincent B. Phelan,

National Bureau of Standards.

E. a. Poynton,

Office of Indian Affairs.

John H. Schaefer,

Procurement Division.

George W. Trayer,

United States Forest Service.

Elsmere J. Walters,

Quartermaster Corps, War Department.
UNITED STATES DEPARTMENT OF COMMERCE • Harry L. Hopkins, Secretary

NATIONAL BUREAU OF STANDARDS • Lyman J. Briggs, JJirector

BUILDING MATERIALS

and STRUCTURES

REPORT BMS18

Structural Properties of "Pre-Fab"

Constructions for Walls, Partitions,

and Floors Sponsored by the

Harnischfeger Corporation

by HERBERT L. WHITTEMORE, AMBROSE H. STANG,

and VINCENT b. phelan

ISSUED MAY 17, 1939

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

FOR SALE

STATES GOVERNMENT PRINTING OFFICE • WASHINGTON

BY THE SUPERINTENDENT OF DOCUMENTS, WASHINGTON, D. C. • PRICE

1939

10 CENTS
Foreword

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

structural properties of constructions intended for low-cost houses and apartments.

Practically all of these constructions were sponsored by groups within the building

industry which advocate and promote the use of such constructions and which have

built and submitted representative specimens as outlined in report BMS2, Methods of

Determining the Structural Properties of Low-Cost House Constructions. The sponsor

is responsible for the representative character of the specimens and for the detailed

description given in each report. The Bureau is responsible for the accuracy of the

test data.

This report covers only the load-deformation relations and strength of the structural

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

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

would be subjected in actual service. It may be feasible to determine later the heat

transmission at ordinary temperatures and the fire resistance of these same constructions

and perhaps other properties.

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

and BMS2. The technical facts on these and other constructions provide the basic

data from which architects and engineers can determine whether a construction meets

desired performance requirements.

Lyman J. Briggs, Director.

[H]
Structural Properties of " Pre-Fab" Constructions for Walls,

Partitions, and Floors Sponsored by the Harnischfeger Corporation

by HEKBERT L. WHITTEMOKE, AMBROSE H. STAN(i, and VINCENT B. PHELAN

C O N 'J' E N T S

Page

Foreword ii

I. Introduction 1 II. Sponsor and product 2

III. Specimens and tests 2 IV. Wall AZ 2

1. Sponsor's statement 2

(a) Materials 2

(b) Description 4

(1) Three-foot four-inch

wall specimens 4

(2) Six-foot eight-inch wall specimens 6

(c) Comments 6

2. Compressive load 6

3. Transverse load 7

4. Concentrated load 9

5. Impact load 9

6. Racking load 10

V. Partition BA 11

1. Sponsor's statement 11

(a) Materials 11

(b) Description 11

Page V. Partition BA—Continued.

1. Sponsor's statement—Continued.

(c) Comments 13

2. Impact load 13

3. Concentrated load 13

VI. Floor BB 14

1. Sponsor's statement 14

(a) Materials 14

(b) Description 14

(c) Comments 15

2. Transverse load 16

3. Concentrated load 16

4. Impact load 17 VII. Floor BC 17

1. Sponsor's statement 17

(a) Materials 17

(b) Description 17

(c) Comments 18

2. Transverse load . 18

3. Concentrated load 19

4. Impact load 19

VIII. Additional comments by sponsor 20

ABSTRACT

For the program on the determination of the struc- tural properties of low-cost house constructions, the Harnischfeger Corporation submitted 33 specimens

representing their "Pre-Fab" constructions for walls, partitions, and floors. The wall specimens were subjected to compressive,

transverse, concentrated, impact, and racking loads; the partition specimens to impact and concentrated

loads; and the floor specimens to transverse, concentrated, and impact loads The transverse, concentrated,

and impact loads were applied to both faces of wall specimens. For each of these loads three like specimens were tested, the concentrated-load tests being made on undamaged portions of the specimens used for the

transverse or impact tests. The deformation under

load and the set after the load was removed W'ere measured for uniform increments of load up to the maximum load, except for concentrated loads, for which the

set only was determined. The results are presented

graphically and in tables.

I. INTRODUCTION

In order to provide technical facts on the per- formance of constructions which might be used

in low-cost houses, to discover promising constructions, and ultimately to determine the

properties necessary for acceptable performance, the National Bureau of Standards has in- vited the building industry to cooperate in a program of research on building materials and

structures for use in low-cost houses and apartments. The objectives of this program are described in report BMSl, Research on Building Materials and Structures for Use in

Low-Cost Housing,' and that part of the

program relating to structural properties in

1 Price 10 cents. See cover page II.

[1]
I

report BMS2, Methods of Determirdng the

Stnictiiral Properties of Low-Cost House Constructions.^

As a part of the research on structural properties, six masonry wall constructions have been

subjected to a series of standardized laboratory

tests to provide data on the properties of some

constructions for which the behavior in service

is generally known. These data are given in

report BMS5, Structural Properties of Six

Masonry Wall Constructions.^ Similar tests have been made on wood-frame constructions

by the Forest Products Laboratory of the

LTnited States Department of Agriculture, the

results of which will be given in a subseciuent

report in this series. This report describes the structural properties of constructions sponsored by one of the

manufacturers in the building industry. The

specimens were subjected to compressive, transverse, concentrated, impact, and racking loads,

simidating loads to which the elements of a house are subjected. In actual service, compressive loads on a wall are produced by the

weight of the roof, second floor and secondstory walls, if any, furniture and occupants,

and snow and wind loads on the roof. Transverse loads on a wall are produced by the wind,

concentrated and impact loads by furniture or accidental contact with heavy objects, and

racking loads by the action of the wind on

adjoining walls. For nonload-bearing partitions, impact loads may be applied accidentally

by furniture or by a person falling against the

partition, and concentrated loads by furniture or by a ladder or other object leaning against

the partition. Transverse loads are applied to

floors by furniture and by the occupants; con- centrated loads by furniture, for example, the

legs of a piano; and impact loads by objects

falling on the lloor or by persons jumping on

the floor. The deformation and set under each increment of load were measured because the suitability of a wall, partition, or floor construction

depends in part on its resistance to deformation under load, and whether it returns

to its original size and shape when the load is removed.

II. SPONSOR AND PRODUCT

The specimens were submitted by the Harnischfeger Corporation, Milwaukee, Wis., and

represented constructions marketed under the

trade name "Pre-Fab Homes." These constructions consisted of prefabricated panels

with welded sheet-steel frames for walls, partitions, and floors, designed to be erected on masonry foundations, and interlocked by special key-and-tapered-pin fastenings.

III. SPECIMENS AND TESTS

The specimens represented tliree elements of a house which were assigned the following

symbols: Wall, AZ; partition, BA; and floors,

BB and BC. The specimens were assigned

designations in accordance with table 1. Table 1.

Specimen designations

Element

Wall. Do_

Do. Do. DoDo.

Do.

Do.

Partition

Do

Floor. Do..

Do.. Do.

Do..

Do..

Construc- tion symbol

AZ

AZ

AZ

AZ

AZ

AZ

AZ

AZ

BA

BA

BB

BB

BB

BC

BC

BC

Specimen

designation

CI, C2, CS..

Tl, T2, TS_. T4, T.5, re.. PI, Pi, P3<^.

PJf, P5, PS".

II, IB, 13...

li, 15, Rl, R2, RS..

II, IS. 13.... PI, P2, PS'-.

Tl, T2, TS.. PI, P2, PS^.

It, 12, IS.... Tl T2 T3

Pi', P~2, PS\

II, 12, IS....

Load

Compressive. _ Transverse

do

Concentrated. do Impact

do Racking Impact

Concentrated.

Transverse Concentrated. Impact

Transverse

Concentrated. Impact

Load applied

Upper end.

Inside face. Outside face. Inside face. Outside face. Inside face. Outside face. Near upper end.

Either face. Do. Upper face. Do.

Do.

Do.

Do.

Do.

- Price 10 cents.

3 Price 15 cents.

"These specimens were undamaged portions of the specimens used for the transverse or impact tests. The specimens were tested in accordance

with BA/rS2, Methods of Determining the

Structural Properties of Low-Cost House Constructions,* which also gives the requirements

for the specimens and describes the presentation

of the results of the tests, particularly the loaddeformation graphs.

The tests were begun April 18, 1938, and

completed April 25, 1938. The sponsor's repre- sentative witnessed the tests.

IV. WALL AZ

1. Sponsor's wStatement

(a) Materials

Steel.—Copper-bearing sheets, hot-rolled, annealed, and pickled. The chemical composition

* Price 10 cents.

[2]
of the steel is given in tnble 2 and the mechanical properties in table 3. Granite City

Steel Co.

Table 2.-—Chemical cnviposilion of the steel

Element

Content

Actual Specified minimum

S pecifled maximum

Carbon.

Percent

0.17

.37 .011

.031

. 31

Percent

0. 15 .35

Percent

0. 25 .48 .008

.044

Manganese

Phosphorus _. _. Sulfur... Copper... . . .20

Table 3.Mechan ical properlies of the steel

Direction Yield

point

Tensile strength Elongation

in 8 in.

In direction of rolling Across direction of rolling . .

lb/in.' 43. 450

43, 350

Wlin.i

60, 400

63, 9.50

Percent

24. 2

20. 1

The steel was prepared for paint by cleaning

in a high-pressure-spray washing machine.

The cleaning solution was sulfonated naphthalene, sodium orthophosphate, and sodium

chromate in an aqueous solution maintained at 200° F. Welds.—Electric-arc welds made with mildsteel electrodes and a shielded arc. P & H

"Hansen" arc welder, d-c rotary type.

Paint. —Priming, rust-resisting, red. The

formula for the paint is given in table 4. Pittsburgh Plate Glass Co.

Table 4.

Formula for the paint

Paint Pigment Vehicle <

Ingredient Content Ingredient Content Ingredient Content

Pigment. _. Vehicle

Percent30

70 Zinc chromate. . .. Iron o.xide ...

Percent30

50

20

Nonvolatile.-.

Volatile . ..

Percent44

56

100

Inert (asbestine and

silica)

ino 100

» Alkyde type, 45 percent linseed oil modified synthetic resin.

Insnlating hoard.—Wood-fiber, 1/2 in. thick,

sized to decrease the moisture absorption;

modulus of rupture, 1,090 Ib/in.^; tensile strength, 646 lb/in. ^; density (at 20-percent

humidity), 25.0 lb/ft''; thermal conductance

(0.5 in. thickness), 0.77 Btu/hr ft^ °F; absorption, 48-hr immersion, 25.2 percent by weight.

The air infiltration through the insulating

board is given in table 5 and the hnear cxjjansion in table 6. Ilomasote Co.'s "Ilomasoto "

Table 5.

Air infdtralion Ihrongh the irisulaliiKj hoard

Wind velocity (mph)

Air inTiltra- tion Wind velocity (mph)

Air infiltra- tion

20

fPlhrUtt

0. 1

. 5

1. 'J

80 mr/ft'

4.3

7.7 40. 100 00

Table 0.

Linear expansion of the iii.sulal iiKj hoc/nl

Helative-humidity

range (percent) Linear expansion Relative-humidity

range (percent) Linear expansion

Percent

0. 30 .33

20 to 85 Percent

0.45

20 to 70 20 to 95 . .50

Plywood.—Five-ply, Douglas fir, 1/2 in. thick,

hot-press phenol-resin bonded; modulus of rupture, 8,500 Ib/in.^ The linear expansion of the

plywood is given in table 7. Harbor Plywood

Corporation's "Super Harboard."

Table 7.-—Linear expansion of the plywood

Relative-humidity

range (percent) Linear ex- pansion

Relative-humidity

range (percent) Linear ex- pansion

Percent Percent

25 to 60 0. 06

. 12 25 to 100 0. 15 25 to 90

Three-ply, Douglas fir, in. thick, bonded

with water-resistant glue. Weyerhaeuser Sales

Corporation.

Paper.

Sheathing, felt-paper base, saturated with

high-melting tar (above 180° F); weight, 30

lb/500 it'. The Barrett Co.'s "Slaters Felt."

Kraft, duplex, moisture-resistant, consisting of two sheets of 30-lb Kraft paper (basis 24

by 36 in.; 480 sheets) cemented with asphalt;

36 in. wide; weight, 38.2 lb/1,000 W. Re.xford

Paper Co.'s "Vapor Shields."

Shingles.—Red cedar. No. 1, 18 in. long, five butts to 2^4 in., stained white. The Edham

Co., Inc.

[3]
Shingle stain.

Corporation

-White. Weyerhaeuser Sales

Screws. Wood, in., No. 10 (0.190-ui.

threads per in., flat head, made from

steel, not heat-treated, plated with

Rockford Screw Products Co.

Self-tapping, % in.. No. 8 (0.164

15 threads per in., flat head, made

1015 steel, hardened, "Parkerized."

Screw Products Co.'s "Type A."

diam), 13

SAE 1015

cadmium.

-in. diam),

from SAE

Rockford

Figure 1. —Three-foot Jour-inch wail specimen AZ.

A , stud; B, sill; C, wall plate; D, insulation; E, furring strip; F, sheathing;

G, sheathing paper; //, shingle siding; /, furring strip; J, moisture

barrier; K, ground; L, lath; M, plaster.

Nails.

Shingle, 3d, VA in. long. No. 13 gage

(0.0915-in. diam), zinc coated.

Berry-box, in. long. No. 17 gage (0.0540-

ia. diam).

Wood ground.—Western white pine, S4S (surfaced four sides).

Lath.—Gypsum, 40 by 16 by % in. United

States Gypsum Co.'s "Perforated Rocklath."

Plaster. Base coat, 2 parts sanded plaster and 1 part wood-fibered plaster, by volume. The

sanded plaster was United States Gypsum Co.'s "Red Top Sanded Plaster" containing approximately 1 part neat gypsum plaster and 2 parts

dry sand, by weight. The wood-fibered plaster was Grand Rapids Plaster Co.'s "Climax."

Finish coat, 1 part water to 2 parts pre- pared gypsum plaster, by volume. The pre- pared gypsum plaster was United States Gypsum Co.'s "Red Top Sand Float Finish."

{h) Description '

(1) Three-foot four-inch wall specimens.—The

3-ft 4-in. wall specimens were 8 ft 0 in. high,

3 ft 4 in. wide, and 6% in. thick. Each specimen consisted of a welded sheet-steel frame to which the faces were fastened. The frame

consisted of three sheet-steel studs. A, shown in

figures 1 and 2, fastened to a sheet-steel sill, B,

and a sheet-steel wall plate, C, by welds, and

covered with one coat of paint applied by

spraying. The outside face was a double wall,

consisting of insulation, D, furring strips, E,

and sheatliing, F, fastened to the frame by

wood screws and covered by sheathing paper, G,

and wood-shingle siding, H. The inside face consisted of furring strips, /; moisture barrier, J;

wood ground, K; gypsum lath, L; and plaster, M.

The price of this construction in Washington,

D. C, as of July 1937 was $0.41/ftl

Studs.—The studs. A, were chamiels, 3 by

1% in., 8 ft 0 in. long, formed from sheet steel,

No. 15 U. S. Std. Gage (0.0689 in. thick).

The studs were crimped at each end to fit between the flanges of the sill and the wall

plate. The web of each stud had seven vertical

and four horizontal slots, iKe by %6 in., along

the centerline for key-and-pin fastenings to adjacent panels, and seven %-in. holes for conduits. There were )^-in. holes in both

flanges opposite five of the vertical slots to provide for the insertion of the pins into the

keys. The inside flange of each outer stud had

two reinforcement plates, P~72 by 1 by K in.,

[4]
Figure 2.— Details of umll specimen AZ.

A, stud; B, sill; C, wall plate; D, insulation; E, furring strip; sheathing; G, sheathing paper; //, shingle siding; /.furring

strip; J, moisture barrier; isT, ground; i, lath; M, plaster.

fastened to the inside of the flange near the

lower end by welds. There was one %-in. tapped hole through each plate and flange for bolt connections to a floor panel.

The sill, B, was 3 ft 3% in. long and

identical in section with the studs, A. The

web had two transverse and one longitudinal

slot, iKe by %f, in., and three %-in. holes. Each

flange had a )2-in. hole opposite the longitudinal

slot.Wall plate. —The wall plate, C, was the same

as the sill, B

Insulation.—The insulation, D, was one piece

of insulating board, 8 ft 0 in. by 3 ft 3% in. by

Yi in., fastened to the flanges of the studs, sill, and wall plate by wood screws, spaced 9 in. on

centers. The heads of the screws were on the

inside of the flanges and the screws extended

through the insulation and the furring strips,

into the sheathing.

Furring strips.—The furring strips, E, were

strips of insulating board, Ijihj in., fastened

to the insulation by berry-box nails, spaced 9

in. on centers. There were three vertical strips, one over each stud, and two horizontal strips, one at each end of the specimen.

Sheathing.—The sheathing, F, was one piece

of 5-ply plywood, 8 ft 0 in. by 3 ft 3% in. by

K in. Sheathing paper.—The sheathing was covered

with one layer of sheathing paper, (7, 8 ft 0 in. by 3 ft 3% in., fastened to the plywood by the

nails fastening the shingles.

Shingle siding.—The shingles, H, were laid 8

in. to the weather and fastened to the sheathmg

by shingle nails, four per sliingle.

Furring strips.—The furring strips, /, were

3-ply plywood, in. thick, fastened to the

inside flanges of the studs, sill, and wall plate by

self-tapping screws, spaced 9 in. on centers. There were two horizontal and three vertical

furring strips. The horizontal strips were 7 in. wide and were fastened to the lower end of the

specimen. The lower edge of the bottom strip

[5]
was % in. above the bottom of the sill, and in a house it would separate the frame of the floor panel from the frame of the wall panel. The

next strip was 1% in. above the bottom strip

and in a house would provide for fastening the

baseboard. The vertical strips were 2 in. wide

and extended from the horizontal strips to the

upper end of the specimen, one along each stud,

and were fastened so that one edge was on the

flange, in. from the web, and the other edge

extended beyond the edge of the flange.

Moisture barrier.—The moisture barrier, J, was one sheet of Kraft moisture-resistant paper,

8 ft 0 in. by 3 ft 3% in., fastened by the nails

which fastened the lath. Ground.—The ground, K, was a wood strip,

% by % in., 3 ft 4 in. long, fastened to the bottom

furring strip, /, by shingle nails, spaced 11 in. on centers. The lower edge was flush with the

lower edge of the furring strip.

Lath.—The lath, L, was 5 pieces of gypsum

lath, 40 by 16 by % in., and 1 piece, 40 by

14}^ by Ys in., fastened to the furring strips,

/, by shingle nails, spaced 4 in. on centers.

Plaster.—The plaster, M, was % in. thick and

consisted of a base coat and a finish coat.

(2) Six-foot eight-inch wall specimens.—The

6-ft 8-in. wall specimens were 8 ft 0 in. high,

6 ft 8 in. wide, and 6% in. thick. Each specimen consisted of two panels, identical with the

3-ft 4-in. specimens, interlocked by four keyand-pin fastenings. The method of interlocking the studs of adjacent panels is shown in

figure 3. The keys were made of sheet

steel. No. 7 U. S. Std. Gage (0.1838 in. tliick),

cadmium plated. The tapered pins were made

of sheet steel, No. 11 U. S. Std. Gage (0.1225 in. thick), cadmium plated.

(c) Comments

The wall panels are fabricated at the factory

in standard widths of 1 ft 8 in. and 3 ft 4 in. and

a height of 9 ft 4^%^ in. The double wall,

consisting of insulation, furring strips, and

sheathing, is attached at the factory as are also the furring strips for the inside face. The

inside and outside finishes are applied after erection.

The panels are designed to be erected on a masonry wall foundation. Insulating-board

strips, 5K by ji in., impregnated with asphalt.

are laid on top of the foundation walls to form

a bearing for the floor and wall panels. The

wall panels are fastened to the floor panels by

bolts and to adjacent wall panels by the keyand-pin fastenings shown in figure 3. Corners

are made with a corner panel fastened by keyand-pin fastenings to the wall panels. Panels

Figure 3.Method of interlocking wall panels with key-and-pin fastenings

for second-story walls rest on sheet-steel

brackets, which support the second floor,

and are fastened to the first-story panels by

key-and-pin fastenings. Doors and windows

are installed in panels at the factory.

The outside finish may be paint, wood

sliingles or lap siding, composition shingles,

stucco, or brick veneer. The inside is usually

finished with plaster on gypsum lath.

2. Compressive Load

Wall specimen under compressive

load is shown in figure 4. The results for wall

[6]
specimens AZ~C1, C2, and C3 ai-e shown in table 8 and in figures 5 and 6. Table 8.

Structural properties of wall AZ

[Weight, 10.6 Ih/ft']

Loa.l Load applied

Specimen

designation

Failure

of

loaded

face,

height

of

drop

Failure

of

opposite

face,

height

of

drop

Maximum

height

of

drop

Maximum

load

Compressive

Transverse

Do

Upper end, 2.03 in. from the inside face."

|C7..

/' /' t>Kipslft

8. 63

9. 88

8] 76 \C2

\C3

9. 09

Inside face; span, 7 ft 6 in.

\T1

tb/Jt 2 174 170

168

rpq

171

Outside face; span, 7ft

6 in.Average

) 176

180

181

ConcentratedDo

1 ' - - Tfi

179

Inside face iPl.-

lb 328

339

400 {P2

Average

[PS..

366

Outside face.. ... ...

•= 1, 000

•= 1, OCO

•= 1,000 |k:

Average .

|P6..

1, 000

Inside face; span, 7 ft 6 in.Average .

(/3...

3. 5

3. 5 4.0

9.0

7.5

9. 5

ilO. 0

dlO.O

•110.0

Impact- - -

Do

3. 7 8. 7 •110. 0

Outside face; span, 7

ft 6 in. Average

\U--

75...

[76...

8.0

9.0

8. 5

3.0

5 5

3. 5

•110. 0

'110.0

'110.0

Racking . ...

8. 5 4.0 •110, 0

Near upper end.

[Rl 1.20

1. EO

1. 23 \R2

Average

\Rf. 1.31

" For the compressive load the thickness of the specimens was taken as Sin., that of the structural portion onlv.

b A kip is 1,000 lb.

" Specimen did not fail. Test discontinued.

<> Test discontinued. For determining the eccentricity of loading

in the compressive test, the thickness of the

specimens was taken as the thickness of the

studs, and the compressive loads were applied

one-third the tliickness of the studs from the

inside edge of the studs. The shortenings and

sets shown in figure 5 for a height of 8 ft were computed from the values obtained from the

compressometer readings. The gage length of

the compressometers was 7 ft 6 in. The lateral deflections shown in figure 6 are plotted to the

Figure 4.WulL .•^iiccniicn, AZ-Ci under compressive

load

light of the vertical axis for deflections of the

specimens toward the outside face, and to the

left for deflections toward the inside face. For

compressive loads up to about 5 Idps/ft the

specimens deflected toward the inside face,

because the stifl'ness of the inside face more

than offset the effect of the eccentric loading.

For loads greater than 5 kips/ft the specimens

deflected in the opposite direction, that is, toward the outside face, possibly because of progressive local failure of the inside face. Each of the specimens failed by buckling of one or more studs near midheight. In each

case the buckling occurred at holes in the

flanges of the studs. For specimen CI the

plaster and lath separated from the lower end of the specimen.

3. Transverse Load

The results are shown in table 8 and in figure

7 for wall specimens AZ-Tl, T2, and T3, loaded

135029°—39 2 [7]
12

8

Co

0)

I-Oo

4

2

0

—

<»

i»

—

AZ

240

200

160

120

(0I 80

0 0.02 OM O.OB

shorfening in.^3 ft

Figure 5.Compressive load on wall AZ.

Load-shortening (open circles) and load-set (solid circles) results for speci- mens AZ-Cl, C2, and C3. The load was applied 2.06 inches from the

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

12

0

—-i

i /

1

1

AZ-I

8

5; 4

I-oo

0

»—

3

1

\

1

J

AZ

0 0.2 0.4 0.6

deflection in.

Figure 7. —Transverse load on wall AZ, load applied to inside face.

Load-deflection (open circles) and load-set (solid circles) results for specimens AZ-Tl, T2, and TS on the span 7 ft 6 in.

240

=^200

160

-i: 40

0 0.2 0.4 0.6

lateral deflecf/on in. Figure 6.

Compressive load on ivall AZ.

Load-lateral deflection (open circles) and load-lateral set (solid circles) results for specimens AZ-Cl, C2, and C3. The load was applied 2.00 inches from the inside face. The loads are in kips per foot of actual width of specimen. The deflections and sets are for a gage length of 7

ft 4 in., the gage length of the deflectometers.

0

/

/

T

T

/L

Y

AZ4- 0 0.2 0.4

defiedion

0.6

in. Figure 8.—Transverse load on wall AZ, load applied to outside face.

Load-deflection (open circles) and load-set (solid circles) results for specimens AZ-T4, T5, and TS on the span 7 ft 6 in.

[8]
on the inside face, and in figure 8 for wall speci- mens AZ-TJ^, T5, and T6, loaded on the outside face. Each of the specimens Tl, T2, and T3 failed

by buckling of the studs near midspan at holes

in the flanges of the studs.

For each of the specnnens T4, T5, and T6 the

plaster cracked transversely across the speci600

I

o

• • —

T

/

/ •

•

AZ-I 0

indenfafion in. Figure 9.

Concentrated load on wall AZ, load applied

to inside face.

Load-indentation results for specimens AZ-Pl, P2, and P3. men in two or more places between the loading

rollers. The first cracks occurred at loads of

110, 160, and 160 Ib/ft^ and deflections of 0.41,

0.72, and 0.70 in. for specimens T4, T5, and T6,

respectively. Each of the specimens failed by

buckling of the studs near midspan at holes in

the flanges of the studs.

4. Concentrated Load

The results are shown in table 8 and in figure

9 for wall specimens AZ-Pl , P2, and P3, loaded on the inside face, and in figure 10 for wall

specimens AZ-PI)., P5, and P6, loaded on the

outside face. The concentrated loads were appHed to the

inside face of specimens PI, P2, and PS on the

plaster midway between two studs. Each of

the specutiens failed hy jjuiicliiii;^- of Ilic disk

through the inside face. The concentrated loads were applied to llip outside face of specimens PJ)., P5, and Pll on t he

shingle siding midway between two studs.

For specimens PJf and P5, the shingle to which

the load was apphed split at a load of 900 1 1), and the indentations after a load of 1,000 lb were 0.154 and 0.243 in., respectively. For

specimen P6 the disk punched through the

loaded shingle at 900 lb, and the indentation

after a load of 1,000 lb was 0.263 in.

5. Impact Load

The results are shown in table 8 and in figure 11 for wall specimens AZ-Il, 12, and 13, loaded on the inside face, and m figure 12 for wall

looo

^800

Si

-^600

I

^400

s^200

0

—B «—

—1 »—

—0-

< »—

r

1 » —9^ •—

»

>

/

L

1

AZ-4 0 0.1 0.2 0.3

indenfafion in. Figure 10.

Concentrated load on wall AZ, load applied

to outside face.

Load-indentation results for specimens AZ-Pi, Po, and P6.

specimens AZ-II)., 15, and 16, loaded on the

outside face. The deflections shown m figure 11 were obtained from measurements to the outside face,

whereas the sets were measured to the mside

face. For drops greater than 7 ft, some of the

sets exceeded the deflections because the inside

face failed and the center stud deformed to

[9]
such an extent that the set readings had to Lo

taken on the mside of the msulation.

The impact loads were applied to the center

of the inside face of specimens II, 12, and 13,

the sandbag striking the plaster approximately

over the center stud. At drops of 2.5, 2, and 3

ft for specimens II, 12, and 13, respectively, the

plaster inside face of each specimen cracked

8

6

4

0

/t•

»—

7?

B—

u

V AZ-I 0 2 4

deflecfion

6

in. Figure 11. -Impact load on ivall AZ, load applied to inside face.

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

circles) results for specimens AZ-Il, 12, and IS on the span 7 ft 6 in.

transversely across the specimen at a lath joint.

The deflections at these drops were 0.80, 0.69,

and 0.80 in. for specimens II, 12, and 13, re- spectively. At drops of 3.5, 3.5, and 4 ft for specimens II, 12, and 13, respectively, the in- side face of each specimen failed by rupture of the lath and plaster under the sandbag. For

specimens II and 13 after a drop of 10 ft the

sheatliing was separated from the furrmg strips

and all the studs buckled. For specimen 12

after a drop of 10 ft the sheathing was separated

from the furring strips and the center stud

budded.

The impact loads were applied to the center

of the outside face of specimens 14, 15, and 16,

the sandbag striking the sliingle siding approximately over the center stud. At drops of 2,

3.5, and 3 ft for specimens 14, IB, and 16, re- spectively, the plaster inside face of each specimen cracked transversely across the specimen

at a lath joint. The deflections at these drops were 0.80, 1.08, and 1.10 in. for specimens 74,

15, and 16, respectively. At drops of 3, 6.5 and

3.5 ft for specimens /4, 15, and 16, respectivclv,

the inside face of each specimen failed by one or more pieces of lath with plaster (40 by 16 in.)

falling down. For each specimen after a drop

of 10 ft most of the inside face had fallen down

in pieces, the sheatliing separated from the

furring strips, and the studs buckled.

0. Racking Load

Wall specimen AZ-R3 under racking load is shown in figure 13. The results for wall speci10

6

6

4

2

Oc

—

—

J

>—

/

/

n

IT

AZ-4 0 2 4

defiedion

6

in. Figure 12. Impact load on wall AZ, load applied to outside face.

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

circles) results for specimens AZ-I4, IS, and 16 on the span 7 ft 6 in.

mens AZ-Rl, R2, and R3, are shown in table 8

and in figure 14. The deformations and sets shown in figure 14

for a height of 8 ft were computed from the

values obtained from the measuring-device

readings. The gage length of the vertical

measuring device was 6 ft 6 in. The gage

[10]
length of the horizontal measuring device was G

ft 11 in. Each of the specimens failed by the insulation and sheathing separating from one or more

studs in the panel to which the load was applied. The screws fastening the double wall to the studs and wall plate deformed under the

shearing load and the heads of some of the screws finally pulled tlu-ough the flanges of the

studs and wall plate. In addition, the heads of some of the nails fastening the lath to the fur- ring strips pulled through the lath. For

specimen Rl there was a slight crack in the

plaster at the middle of the specimen and for specimen E3 a crack near the upper end.

V. PARTITION BA

1. Sponsor's Statement

(a) Materials

Steel.—Copper-bearing sheets, hot-roUed, annealed, and pickled. The chemical composition of the steel is given in table 2 and the

mechanical properties in table 3. Granite City

Steel Co.

Welds.—Electric-arc welds made with mildsteel electrodes and a shielded arc. P & H

"Hansen" arc welder, d-c rotary type.

Paint.—Priming, rust-resisting, red. The

formula for the paint is given in table 4. Pittsburgh Plate Glass Co.

Plywood.—Tlu-ee-ply, Douglas fir, Yx^ in. thick, bonded with water-resistant glue. Weyerhaeuser Sales Corporation.

Screws.—Self-tapping, % in.. No. 8 (0.164-in.

diam), 15 threads per in., flat head, made from

SAE 1015 steel, hardened, "Parkerized." Rockford Screw Products Co.'s "Type ^4." Wood, grounds.—Western white pine, S4S

(surfaced four sides).

Lath.—Gypsum, 40 by 16 by % in. United

States Gypsum Co.'s "Perforated Rocklath."

Nails.—Shingle, 3d, 1% in. long, No. 13 gage

(0.0915-in. diam), zinc coated.

Plaster. Base coat, 2 parts sanded plaster and 1 part

wood-fibered plaster, by volume. The sanded

plaster was United States Gypsum Co.'s "Red

Top Sanded Plaster" containmg approximately

1 part neat gypsum plaster and 2 parts dry

Figure 13. —Wall specimen AZ-R3 under ruiLi/ig luad.

sand, by weight. The wood-fibered plaster was Grand Rapids Plaster Co.'s "Climax."

Fmish coat, 1 part water to 2 parts pre- pared gypsum plaster, by volume. The pre- pared gypsum plaster was United States Gypsum Co.'s "Red Top Sand Float Finish."

{b) Description

The partition specimens were 8 ft 0 in. high,

3 ft 4 in. wide, and b)i in. tliick. Each specimen consisted of a welded sheet-steel frame to wiiich the faces were fastened. The frame consisted of tlu'ee sheet-steel studs. A, shown in

figure 15, fastened to a sheet-steel soleplate, B,

and a sheet-steel top plate, C, by welds, and

covered with one coat of paint applied by spraying. Plywood furring strips, D, were fastened

to the flanges of the studs and plates on both

sides of the specunen b}^ screws. Wood

grounds, E, and gypsum lath, F, were fastened

to the furring strips by nails, and the faces were

finished with plaster, G.

[11]
The price of tliis construction in Wasliington,

D. C, as of July 1937 was $0.265/ft2.

Studs.—The studs, A, were channels, 3 by

IK in., 8 ft 0 in. long, formed from sheet steel. No. 15 U. S. Std. Gage (0.0689 m. tliick). The

ends of the studs were crimped to fit between

the flanges of the plates. The web of each

stud had seven vertical slots, iKe by %& in., for

key-and-pin fastenings, two slots, 1}{ by ji in., and nine /s-in. holes for conduits. There were

/.2

.t/.O

0.8

^0.6

s>

xO.4.

oio.2

0

0

• 0

r\

<

V

>• DO- 9

• •

L y

?/ • o

'A

» o

fo

AZ 0 0.4 0.3

deformahon

1.2

in./3ff

Figure 14.Racking load on wall AZ.

Load-deformation (open circles) and load-set (solid circles) results for specimens AZ-Rl, R2, and RS. The loads are in kips per foot of actual width of specimen.

%-ixi. holes in both flanges opposite each of three

pairs of slots.

Solejilate.—The soleplate, B, was a channel,

3 by % in., 3 ft 3% in. long, formed from sheet

steel, No. 15 U. S. Std. Gage (0.0689 in. thick).

The web had four slots, iKe by %& in., and four

slots, 2% by Yi in., for fastenings, and four

%-in. holes for conduits. Each flange had four

slots, /8 by K in., and two K-in. holes. Top plate.—The top plate, C, was 3 ft 3% in. long and identical in section with the sole- plate, B. The web had 16 slots, iKe by /i6 in..

for key-and-pin fastenings, and two /s-in. holes

for conduits.

Furring strips. —The furring strips, D, were

plywood, /i6 in. thick, fastened to the flanges of

the studs and plates on both sides of the specimen by screws, spaced 9 in. on centers. There was one horizontal strip and three vertical

strips on each side of the frame. The horizontal strips were 7 in. wide and were fastened

to the lower end of the frame to provide for fastening the baseboards in a house. The

lower edges of these strips were ji in. above the

bottom of the soleplate. The vertical strips

Figure 15.

Partition specimen BA.

A, stud; B, soleplate; C, top plate; D, furring strips; E, ground; F, lath; G, plaster.

were 2 in. wide and extended from the horizontal strips to the upper end of the specimen, one along each stud, and were fastened so that one edge was on the flange, in- from the

web, and the other edge extended beyond the

edge of the flange.

Grounds.—The grounds, E, were wood strips

% by % in., 3 ft 4 in. long, fastened to each

[12]
horizontal furring strip by nails, spaced 11 in. on centers. The lower edges were flush with

the lower edges of the furring strips.

Lath.—The lath, F, was 5 pieces of gypsum

lath, 40 by 16 by % in., and 1 piece, 40 by 14%

by % in., on each side of the specimen, fastened

to the furring strips by nails, spaced 4 in. on

centers.

Plaster.—The plaster, G, was % in. tliick and

consisted of a base coat and a finish coat.

((') Comments

The partition panels, with the furring strips

attached, are fabricated at tbe factory in

standard widths of 3 ft 4 in., and 3 ft /8 in. , and

a height of 8 ft SKe in. Lath and plaster or other inside finishes are applied after erection.

The panels rest on the wood subfloor and are fastened by %-in. nails, with wide flat heads,

driven through the slots in the soleplate. Adjacent panels are fastened by key-and-pin

fastenings and the top plate is similarly fastened

to the ceiling or second-floor panels.

2. Impact Load

The results for partition specimens BA-Il,

12, and 13 are shown in table 9 and in figure 16.

Table 9.

Structural properties of partition BA

[Weight, 12.1 lb/ft']

Load

Impact.

Concentrated-.

Load applied

One face; span, 7 ft 6 in.

Average

One face

Average

\ P2

[ PS

73 'O

ft

3. 5

;j. 0

3. 5

3.3

It

5. 5

4. 5

4. 5

4.8

3.50 375

311

34,5

The impact loads were applied to the center

of one face of each specimen, the sandbag

striking the plaster approximately over the

center stud. At drops of 2, 1.5, and 1 ft for

sj)ccimeiis II, I'H, and /.?, respcx^tively, the, {blas- ter face, opposite the face to wliicli tlie lond was

applied, cracl<e(I transversely across the speci5

§ 5

\ 2

0^.

—

- -

»cr>

f

X)

— -fl

> XV

[7

Y BA 0 12 3

deflection in. Figure 16.

Impact load on partition BA.

Height of drop-deflection (open circle?) and height of drop-.^et (solid

circles) results for specimens BA-Il, 12, and IS on the span 7 ft 6 in.

men at a lath joint. The deflections at these

drops were 0.69, 0.58, and 0.47 in., respectively.

At drops of 2.5, 1.5, and 2 ft for specimens II,

12, and IS, respectively, the plaster face to which the load was applied cracked transversely

across the specimen. Each of the specimens

failed by rupture of the loaded face, falling down

of the opposite face in pieces, buckling of the center stud at midspan, and bending of the

soleplate and top plate.

3. Concentrated Load

Partition specimen BA-P2 under concentrated load is shown in figure 17. The results

for partition specimens BA~P1, P2, and P3, are shown in table 9 and in figure 18. The concentrated loads were applied to one

face of each specimen on the plaster midway

between two studs. Each of the specimens

failed by punching of the disk through the

loaded face.

[13]
long, No. 11)2 gage

Figure 17.

Partition specimen BA-P2 under concentrated load.

VI. FLOOR BB

1. Sponsor's Statement

(a) Materials

Steel.—Copper-bearing sheet, hot-rolled, annealed, and pickled. The chemical composition of the steel is given in table 2 and the

mechanical properties in table 3. Granite

City Steel Co.

Welds.—Electric-arc welds made with mildsteel electrodes and a shielded arc. P & H

"Hansen" arc welder, d-c rotary type.

Paint. —Priming, rust-resisting, red. The

formula for the paint is given in table 7. Pittsburgh Plate Glass Co.

Mood.

Nailing strips, Douglas fir, S4S (sin-faced

four sides).

Subflooring, Douglas fir, S4S (surfaced

four sides).

Flooring, red oak, No. 1.

Nails.

Casing, 8d, 2K in. (0.113-in. diam).

Box, 7d, 2}{in. long, No. 12Kgage (0.0985-

in. diam), cement coated.

Paper.—Sheathing, felt-paper base, satu- rated with high-melting tar (above 180° F);

weight, 30 lb/500 Ur. The Barrett Co.'s "Slaters

Felt."

(b) Description

The floor specimens were 12 ft 6 in. long,

3 ft 4 in. wide, and 9% in. thick. Each specimen consisted of a welded sheet-steel frame to which the subfloor and finish floor were fastened.

The frame consisted of two sheet-steel joists. A,

shown in figure 19, spaced 3 ft 4 in. from web

to web and fastened to sheet-steel end members,

600

oo

•

< • —

/

»•

1

»

•

1•

1m 1 0

indenfafion. in. Figure 18.

Concentrated load on partition BA.

Load-indentation results for specimens BA-Pl, PI, and PS.

B, and to 10 sheet-steel cross struts, C, by

welds, and covered with one coat of paint appUed by spraying. Wood nailing strips, D,

were chnched between the flanges of the cross

struts, and a wood subfloor, E, was fastened to these strips by nails. The subfloor was covered with sheathing paper, F, over which a wood finish floor, G, was fastened by nails.

[1-t]
The price of this construction in Washington,

D. C, as of July 1937 was $0.38/ft^. Joists.—The joists, A, were channels, 8 by

1}^ in., 12 ft 6 in. long, formed from sheet steel,

No. 15 U. S. Std. Gage (0.0689 in. thick).

The webs had 26 slots, 1}U by Kg in., for keyand-pin fastenings, sixteen Yo-in. holes for bolts,

and seven /s-in. holes for conduits. The upper

flange of each joist had eight slots, l^ie by in., and one K-in. hole. End members.—The end members, B, were

3 ft 3% in. long and identical in section with the

joists, A. The ends were crimped to fit between the flanges of the joists. The web of

each end member had four slots, by in., for key-and-pin fastenings, four holes for

bolts, and tliree %-in. holes for conduit. The

upper flange of each end member had four

slots, iKe by %e, in. Cross struts.—The cross struts, C, were

channels, 1% by 1 in., 3 ft 3/8 in. long, formed

from sheet steel. No. 15 U. S. Std. Gage

(0.0689 in. thick), stiffened by a }2-in. half- round longitudinal crimp along the center line

of the web extending to N\itliin 2 in. of the

ends. The struts were placed with the flanges

up. There were seven triangular identations

in each flange, spaced approximately 6 in. on

centers. Nailing strips. —The naihng strips, D, were Douglas fir, 1% by 1% (nominal 2 by 2 in.), 3 ft

in. long, set in the struts flush with the top of

(he joists and fastened by the triangular iri- dentiitions in the flanges of the struts. Subfloor.—The subfloor, consisted of seven

boards, by 5% in. (nominal 1 by 6 in.), 12 ft 6 in. long, fastened to the nailing strips by box

nails, two nails to each strip. There was

approximately % in. between the edges of

adjacent boards.

Sheathing -paper.—The subfloor was covered

with one layer of sheathiiig ])aper, B\ fastened

by the nails which fastened the flooring.

Finish floor. —The finish floor,, G, was oak

flooring, ^^32 by 2]^ in. (nominal 'Kg by 2% in.).

Each strip of flooring was fastened to the subfloor by blind nailing with four casing nails.

(c) Comments

The floor panels, ^vii\\ the subfloor in place, are fabricated at the factory in a standard

width of 3 ft 4 in. and in lengths up to 13 ft 4 in. The finish floor is appUed after erection.

The panels rest on a strip of asphalt-saturated insulating board on top of the foundation

waU and are anchored to the foundation by

anchor bolts and clamps which engage the

lower flanges of the end members. Each floor panel is fastened to a waU panel by fom* /s-in. bolts which engage the tapped reinforcement

plates welded to the studs. The iimer ends of

the panels are supported by an 8-in. I-beam.

Adjacent panels are fastened hy key-and-pin

fastenings.

Figure 19.Floor specimen BB.

^, joist; B, end member; C, cross strut; V, nail- ing strip; E, subfloor; F, sheatbing paper; G,

finish floor.

[15]
Figure 20.

Floor specimen BB-T3

under transverse load.

The pniiels designated BB in this report are used for the first floor of a house having a basement. Where there is no basement, insulating

board is placed between the joists approximately

2 in. below the subfloor and fastened to nailing

strips, % by 2 in., on the underside of the

subfloor.

2. Transverse Load

Floor specimen BB-T3 inider transverse load is shown in figure 20. The results for

floor specimens BB-Tl, T2, and T3 are shown

in table 10 and in figure 21.

Table 10.Structural properties of floor BB

[Weight, 7.59 lb/ft]

Load Load applied

Speci- men

desig- nation

Maxi- mum

height

of drop

Maxi- mum

load

Transverse Upper face; si)an, 12 ft 0 in.Average

1 Tl

i T2

[ T3

ft IblfP144

lf,0 152

Concentrated _-

Impact

149

I'pper face

Average . .

I P2

[ PS

lb

« 1,000

» 1,000

« 1, 000

« 1,000

Upper face; span, 12 ft 0 in.

Average.

1 ^'

{ 12

\ IS

b in. 0

b 10.0

b 10.0

b 10. 0

"> Specimen did not fail. Test discontinued. Test discontinued.

Each of the specimens failed by buckling of

both joists at or between the loading rollers. No failure of the wood finish floor was observed.

3. Concentrated Load

The results for floor specimens BB-Pl, P2,

and PS are shown in table 10 and in figure 22. The concentrated loads were applied to the

finish floor of specimens PI and P3 on a strip of

Z40^—^—^

,—,—,—,—,—,—

0 0.2 OA 0.6

defleciion in. Figure 21.—Transverse load on floor BB.

Load-deflection (open circles) and load-set (solid circles) results for speci- mens BB-Tl, T2, and T3 on the span 12 ft 0 in.

the flooring near an end-matched joint which was not directly over a cross strut, and to specimen P2 on a continuous strip of flooring

which was not over a cross strut. The indentations after a load of 1,000 lb had been applied

[16]
were 0.012, 0.020, and 0.022 for specimens /'/, P2, and PS, respectively, and no other effect was observed.

800

•600

\400

t200

O

O I

A ^ T

c

/

9

I

/

•

/•

y A3

0 0.02 0.04 0.06

inc/eniah'on in. Figure 22.

Concentrated load oh floor BB.

Load-indentation results for siiecimens BB-Pl, P2, pnd PS.

4. Impact Load

The results for floor specimens BB-Il, 12,

and IS are shown in table 10 and in figure 23. The impact loads were applied to the center

of the upper face of each specinien, the sandbag

striking the finish floor midway between the

joists and midway between two cross struts. The sets after a drop of 10 ft were 0.72, 0.73,

and 0.60 in. for specimens II, 12, and IS, re- spectively. For specimen //, one joist buckled,

and for specimens 12 and IS both joists buckled

at midspan. No failure of the wood finish floor was observed.

VII. FLOOR BG

1. Sponsor's Statejvient

(a) Materials

All the materials used for floor BB and the

following additional materials were used for floor BC:

Paper.—Kraft, duplex, moisture-resistant,

consisting of two sheets of 30-lb Kraft paper

(basis 24 by 30 in.; 480 sJiectsJ ccmcnlcd wilh

asphalt; 36 in. wide; weight, 38.2 lh/i,000 ft^. Rexford Paper Co.'s "Vapor 8bi(!lds."

Latk. —Gypsum, 40 by 16 by % in. Liiitcid States Gypsum Co.'s "Perforated Rockliifli."

^ 10

d

^ 6

\ 4.

0

1

f

1

1

1•

1•

11

1

»

1

33

0 I 2

def/ech'on in. Figure 23.

Impact load, on floor BB.

Heigtit of drop-defleetion (open circles) and height of drop-set (solid

circles) results for specimens BB-Il, 12, and 13 on the span 12 ft 0 in.

Nails.—Shingle, 3d, V/i in. long, No. 13 gage

(0.0915-in. diam), zinc coated.

Plaster. Base coat, 2 parts sanded plaster and 1 part wood-fibered plaster, by volume. The

sanded plaster was United States Gypsum Co.'s "Red Top Sanded Plaster" containing approximately 1 part neat gypsum plaster and 2 parts

dry sand, by weight. The wood-fibered plaster was Grand Rapids Plaster Co.'s "Climax."

Finish coat, 1 part water to 2 parts pre- pared gypsum plaster, by volume. The pre- pared gypsum plaster was United States Gyi)-

sum Co.'s "Red Top Sand Float Fhiish."

(6) Descriptioih

Floor specimens BC were the same as floor specimens BB with a plaster ceiling fastened to 10 additional cross struts and nailmg strips.

The cross struts were fastened to the joists by

welds. These additional cross struts and nail-

[17]
ing strips were the same as C and D (fig. 19),

but inverted and fastened so that the nailing

strips were flush with the bottom of the joists.

The lower struts were directly below the upper

struts. The ceiling consisted of a layer of moistureresistant Kraft paper, lath, and plaster. The

240

160

%I20

80

0

—

e—

1

/•

/•

1•

1•

0 0.2 OA 0.6

defleciion In. Figure 24.—Transverse load on floor BC.

Load-deflection (open circles) and load-set (solid circles) results for speci- mens BC-TI, T2, and TS on the span 12 ft 0 in.

lath was 9 pieces of gypsum lath, 40 by 16 by

% m., and 2 pieces 40 by 3 by % in., fastened over the paper to the nailing strips by shingle

nails, spaced 5 in. on centers. The lath was

covered with plaster, fs in. thick, consisting of a base coat and a finish coat. The price of this construction in Washington,

D. C, as of July 1937 was $0.46/ft2.

(c) Comments

The panels designated BC in this report are used for the second floor of a house, and are supported by sheet-steel brackets, which rest on top of the first-story wall panels. The

panels are fastened to the brackets by key-andtapered-pin fastenings, and to the second-story

wall panels by bolts. The finish floor and

ceiling are applied in the field.

2. Transverse Load

The results for floor specimens BC-Tl , T2,

and T3 are shown in table 11 and in flgure 24. Table 11.

Structural 'properties of floor BC

[Weight, 14.1 Ih/ff!]

Load Load applied

Specimen

designation

Failure

of

loaded

face,

height

of

drop

Failure

of

opposite

face,

heisht

of

drop

Maximum

height

of

drop

Maximum

load

Transverse. .

ConcentratedImpact.

Upper face; span, 12 ft 0 in.

Average- _ _-_

( Tt

\ Tt

{ TS

!t ft ft ibifr-146 140

149

145

Upper face . . .

f Pt

{ P2

[ PS

lb

» 1,000

» 1, (100 " 1, 000 Average . » 1, 000

Upper face; span, 12 ft 0 in.

Average

1 1$

I 13

C)

(")

3.5

9.0

4. 5

»10.0 "10.0

"lO.O

C) 5. 7 "10.0

> Specimen did not fail. Test discontinued.

b Did not fail.

" Test discontinued.

1000

%800

^600

os^200

0 0.06

* —fl T

—

r

—

/m—

J,

»

f

/ BC

0.02 0.04

indenfafion in. Figure 25.

Couceidralcd load on floor BC.

Load-indentation results for specimens BC-Pl, P2, and PS. At loads of 80, 100, and 80 Ib/ft^ for speci- mens Tl , T2, and TS, respectively, the plaster

[18]
Figure 26.

Floor specimen ]{(' 1

during irnpacl test.

ceiling of each specimen cracked transversely

across the specimen at a lath joint. The deflections at these loads were 0.32, 0.42, and 0.32

in. for specimens Tl, T2, and T3, respectively.

The ceiling of specimen T2 cracked at another

lath joint at the maximum load. Each of the

specimens failed by buckling of both joists at or between the loading rollers. The buckling

occurred at holes in the upper flanges of the

joists.

3. Concentrated Load

The results for floor specimens BC-Pl, P2,

and PS are shown in table 11 and in figure 25. The concentrated loads were applied to the

finish floor of each specimen on a strip of the

flooring near an end-matched joint which was

not directly over a cross strut. The indentations after a load of 1,000 lb had been applied were 0.017, 0.010, and 0.019 in. for specimens

PI, P2, and P3, respectively, and no other

effect was observed.

4. Impact Load

Floor specimen BC-Il under impact load is shown in figure 26. The results for floor specimens BC~I1, 12, and 13 are shown in

table 11 and in figure 27.

The impact loads were applied to the center

of the upper face of each specimen, the sandbag

defleciion in. Figure 21 —Impact load on floor BC.

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

circles) results for specimens BC-Il, 12, and 73 on the span 12 ft 0 in.

striking the finish floor midway between the

joists and midway between two cross struts.

[19]
Specimen II had an initial transverse crack

across the plaster ceiling. The ceiling of speci- mens 12 and 13 cracked transversely across each specimen at a drop of 1 ft. For each of the

specimens II, 12, and 13 at drops of 3.5, 9.0,

and 4.5 ft, respectively, one piece of lath with

plaster (40 by 16 in.) fell down. The sets after a drop of 10 ft were 0.83, 0.50, and 0.52 in. for specimens II, 12, and IS, respectively.

For specimen II most of the plaster ceiling

had fallen down in pieces, and both joists

buckled at midspan. For specimen 12 about

one-half and for 13 most of the plaster ceiling

had fallen down in pieces, and one joist in each

specimen buckled at midspan. No failure of

the wood finish floor was observed.

VIII. ADDITIONAL COMMENTS BY

SPONSOR

Approximately 133 houses using these constructions were completed or under construction on October 1, 1938. These houses were

built entirely of prefabricated sheet-steel panels.

The ceiling panels were the same as floor panels

BC, except that insulating board, 1-in. thick, was used instead of the finish floor. The roof

panels were similar to floor panels BB, but with

5-in. channels, and with cross struts spaced

2 ft 0 in. on centers, and without the finish

floor.

The ceiling panels were fastened to sheetsteel brackets on top of the wall panels by keyand-pin fastenings. The roof panels were

fastened in the same manner by brackets on

the ceiling panels. The roof was covered with

roofing paper and shingles. The spaces above

the wall panels in cornices and gable ends were

filled with loose insulation.

The sponsor supplied the information contained in the sponsor's statement. The description and drawings of the specimens were

prepared by E. J. Schell and G. W. Shaw of

the Bureau's Building Practice and Specifications Section, under the supervision of V. B.

Phelan, from this information and from the

specimens themselves. That Section also cooperated in the preparation of the report.

The structural properties were determined

by the Engineering Mechanics Section, under

the supervision of H. L. Whittemore and A. H.

Stang, with the assistance of the following

members of the professional staff: F. Cardile,

R. C. Carter, H. Dollar, M. Dubm, A. H.

Easton, A. S. Endler, C. D. Johnson, A. J. Sussman, and L. R. Sweetman.

Washington, December 16, 1938.

[20]
The National Bureau oj Standards was established by act of Congress, approved

March 3, 1901, continuing the duties of the old Office of Standard Weights and Measures

of the United States Coast and Geodetic Survey. In addition, new scientific functions were assigned to the new Bureau. Originally under the Treasury Department, the

Bureau was transferred in 1903 to the Department of Commerce and Labor (now the

United States Department of Commerce). It is charged with the development, construction, custody, and maintenance of reference and working standards, and their

intercomparison, improvement, and application in science, engineering, industry, and

commerce.

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