U. S. DEPARTMENT OF COMMERCE

BUILDING

MATERIALS

AND

STRUCTURES

REPORT BMS47

Structural Properties of

Prefabricated Wood-Frame

Constructions for Walls,

Partitions, and Floors

Sponsored byAmerican Houses, Inc.

by

HERBERT L. WHITTEMORE

and AMBROSE h. stang

with the collaboration of

Thomas R. C. Wilson

Forest Products Laboratory

NATIONAL

BUREAU OF STANDARDS
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 Government agencies concerned with

housing construction and finance, which is cooperating in the investigations through a subcommittee of principal technical assistants.

CENTRAL HOUSING COMMITTEE

SUBCOMMITTEE ON TECHNICAL RESEARCH

Walter Junge, Chairman.

Federal Housing Administration.

Sterling R.

Albert G. Bear,

Veterans' Administration.

Pierre Blouke,

Federal Home Loan Bank Board (Federal Loan Agency)

Carroll W. Chamberlain,

Public Buildings Administration (Federal Works Agency).

Joseph M. DallaValle,

Public Health Service (Federal Security

Agency).

John Donovan,

Farm Security Administration (Agriculture).

A. C. Shire, Vice Chairman.

United States Housing Authority.

March, Secretary.

George E. Knox,

Yards and Docks (Navy).

Vincent B. Phelan,

National Bureau of Standards (Commerce).

Edward A. Poynton,

OflBce of Indian Affairs (Interior).

George W. Trayer,

Forest Service (Agriculture).

Elsmere J. Walters,

Construction Division (War).

CHAIRMEN OF SECTIONS

Specifications Maintenance

Carroll W. Chamberlain Charles Peters

Mechanical Equipment

Robert K. Thulman

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 Silicate 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 United States Department of Agriculture

is cooperating with both committees on investigations of wood constructions.

[For list of BMS publications and how to purchase, see cover page III]
UNITED STATES DEPARTMENT OF COMMERCE • Harry 1.. Hopkins, Secretary

NATIONAL BUREAU OF STANDARDS • Lyman J. Briggs, 1 )ircctor

BUILDING MATERIALS

and STRUCTURES

REPORT BMS47

Structural Properties of

Prefabricated Wood-Frame Constructions for Walls, Partitions, and Floors

Sponsored by American Houses, Inc.

by HERBERT L. WHITTEMORE and AMBROSE H. STANG

with the collaboration of

Thomas R. C. Wilson,

Forest Products Laboratory,

Forest Service, United States Department of Agriculture

ISSUED JUNE 3, 1940

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

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

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • I94O

FOR SALE BY THE SUPERINTENDENT OF DOCUMENTS, WASHINGTON, D. C. • PRICE lO 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 bouses 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 Structural Properties of Low-Cost House Constructions. The

sponsor, therefore, is responsible for the design of the constructions and the description

of materials and methods used in their fabrication. The Bureau is responsible for the

method of testing and for the test results. This report covers only the load-deformation relations and strength of the structural

elements of a house when subjected to compressive, transverse, concentrated, impact,

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

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

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

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 the merits of a construction, for the 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.

[nJ
Structural Properties of Prefabricated Wood-Frame Constructions

for Walls, Partitio ns, and Floors Sponsored by American

Houses, Inc.

by HERBERT L. WHITTEMORE and AMBROSE H. STANG

with the CGllaboratioyi of

Thomas R. C. Wilson, Forest Products Laboratory, Forest Service, United States

Department of Agriculture

CONTENTS

Page

II

m.

IV.

Foreword

I. Introduction

II. Sponsor and product

Specimens and tests Materials

1. Wood

2. Wallboard

3. Nails

4. Sheathing paper 6

5. Staples 6

6. Glue

7. Joint filler

8. Tape

Wall CI

1. Sponsor's statement

(a) Four-foot wall specimens

(b) Eight-foot wall specimens 8

(c) Comments 9 Compressive load 10 Transverse load 11 Concentrated load 11 Impact load 13

2.

3.

4.

5.

Page

141414

VI. Load-bearing partition CJ

1. Sponsor's statement

(a) Four-foot partition spEcimens

(b) Eight-foot partition speci- mens 1.5 (c) Comments 16 Compressive load 16 Transverse load 17 Concentrated load 18 Impact load 18 Racking load 19

VII. Non-load-bearing partition CK 19

1. Sponsor's statement 19

(a) Description of specimens 20

(b) Comments 21

2. Concentrated load 21

3. Impact load 21

VIII. Floor CL 22

1. Sponsor's statement 22

(a) Description of specimens 22

(b) Comments 22 Transverse load 23 Concentrated load 23 Impact load 23

2.

3.

4.

5.6.

2.

3.

4. 6. Racking load 14 IX. Additional comments by sponsor 23

ABSTRACT

For the program on the determination of the structural properties of low-cost house constructions, American Houses, Inc., New York, N. Y., submitted 39 specimens representing wood-frame wall, partition, and

floor constructions. The wall and load-bearing partition specimens were

subjected to compressive, transverse, concentrated,

impact, and racking loads; the nonload-bearing partition specimens to concentrated and impact loads; the

floor specimens to transverse, concentrated, and impact loads. For each of the loads, three like specimens

were tested. The transverse, concentrated, and im- pact loads were applied to both faces of the wall specimens. 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 fables.

I. INTRODUCTION

To provide teclinical facts on the perform- ance of constructions wliich might be used in low-cost houses, to discover promising new con-

[1
structions, and ultimately to determine the

properties necessary for acceptable performance

in actual service, the National Bureau of

Standards has invited 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 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 report BMS2, Methods of Determining the Structural Properties of Low-Cost

House Constructions.

Masonry constructions and wood constructions of types which have been extensively used

in this country for houses were included in the

program because their behavior under widely

different service conditions is known to builders

and the public. The reports on these constructions are BMS5, Structural Properties of Six

Masonry Wall Constructions, and BMS25,

Structural Properties of Conventional WoodFrame Constructions for Walls, Partitions,

Floors, and Roofs. The masonry specimens were built by the Masonry Construction Section of this Bureau, and the wood-frame speci- mens were built and tested by the Forest

Products Laboratory at Madison, Wis.

The present report describes the structural

properties of four elements of a house sponsored by one of the manufacturers in the building industry. The wall and load-bearing partition specimens were subjected to compressive,

transverse, concentrated, impact, and racking

loads, simulating loads to which the walls of a house are subjected. In actual service compressive loads on a wall or load-bearing partition are produced by the weight of the roof, by

second floor and second-story walls or partitions, if any, by furniture and occupants, and

by snow and wind loads on the roof. Transverse loads on a wall and load-bearing partition are produced by the wind, concentrated

and impact loads by accidental contact with

heavy objects, and racking loads by the action

of the wind on adjoining walls. For non-loadbearing partitions, impact loads may be applied

accidentally by furniture or by a person falling

against a partition, and concentrated loads by

a ladder or other object leaning against a partition. Transverse loads are applied to floors by,

furniture and by occupants; concentrated loads

by furniture, for example, the legs of a piano;

and impact loads by objects falling on the floor or by persons jumping on the floor. The deflection and set under each increment

of load were measured because, considered as a' structure, the suitability of a construction depends not only on its resistance to deformation

when loads are applied, but also on whether itj returns to its original size and shape when the

loads are removed.

II. SPONSOR AND PRODUCT

The specimens were submitted by American

Houses, Inc., New York, N. Y.

The constructions consisted of wpod-frame

wall, load-bearing partition, non-load-bearing

partition, and floor sections, prefabricated in a shop and assembled at the building site to form the house.

III. SPECIMENS AND TESTS

The specimens represented four elements of a house which were assigned the following symbols: Wall, CI; load-bearing partition, CJ;

non-load-bearing partition, CK; and floor, CL.

The individual specimens were assigned the

designations given in table L

Table 1.Specimen designations, wall CI, load-bear- ing partition CJ, non-load-bearing partition CK, and

floor CL

Element

Wall.

Lnad-bearing partition.

Non-Ioad-hearing

titinn.

Floor

-

Specimen

designation

CI, C2, C3^.

Tl, T2, T3.. Ti, T5, T6^. PI, PS • Pi, P5, P6 > II, 12, IS U, 16, 16 Rl, R2,

'CI, C2, CS...

Tl, T2, TS... PI, P2, PS a_ //, 72, IS Rl, R2, R3.^.

(PI, P2, PS o. 12, IS

Tl, T2, TS... PI, P2, PS a. 11,12,13

Load

Compressive.

Transverse--- do

Concentrated

do Impact

do Racking

Compressive..

Transverse Concentrated. Impact

Racking

Concentrated. Impact

Transverse Concentrated. Impact

Load applied

Upper end.

Inside face. Outside face. Inside face. Outside face. Inside face. Outside face. Top plate. Upper end. Either face. Do. Do. Top plate.

Either face. Do. Upper face. Do.

Do.

» The concentrated and impact loads were applied to the same speci- mens. The concentrated load was applied first. The specimens were tested in accordance

with the procedure outlined in BMS2, Methods

[2]
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 load-deformation graphs.

Only three load-bearing partition specimens

were tested under the transverse, concentrated,

and impact loads, not six specimens, as required

by BMS2. Inasmuch as the load-bearing partition construction was symmetrical about a

plane midway between the faces, the results

for these loads applied to one face of the speci- mens should be identical with those obtained

by apply iiig the loads to the other face. For the compressive load the thiclmess of

the wall was taken as the thickness of the

structural portion, that is, the distance from

the inside surface of the studs to the outside

surface of the studs. The compressive load was applied along a line parallel to the inside

face and at a distance from the inside surface

of the studs of one-third the thickness of the

wall. Also, the thickness of the load-bearing

partition was taken as the thickness of the

structural portion, that is, the distance from

one surface of the studs to the other surface.

The load was applied one-tliird this thickness

from one surface of the studs.

Since the faces of the wall and partition speci- mens were not flush with the ends of the specimens, the steel-loading plates were not in contact with the faces, and therefore the compressive load was applied only to the top and

floor plates. Wood-frame constructions imder

compressive load show considerable local shortening, caused by crushing of the floor plate and

top plate at the ends of the studs. As a result,

the shortening of the entire specimen is not

proportional to the value obtained from compressometers attached to the specimen over

only a portion of its height. Therefore, the

shortenings and sets were measured with compressometers attached to the steel plates

through which the load was applied, not

attached to the specimen as described in BMS2.

The indentation under concentrated load and

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

The apparatus is shown in figure 1. The load was applied to the steel disk, A, to wliich the crossbar, B, was rigidly attached.

Figure 1.Apparalus for cona tiirated-load test. A, disk; B, crossbar; C, spring dynamometer; D, stand; E, dial micrometer.

The load was measured by means of the 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 disk.

The micrometers were graduated to 0.001 in., and readings were recorded to the nearest

division. The initial reading (average of the

micrometer readings) was observed under the

initial load, wliich included the weight of the

disk and dynamometer. A load was applied

to the disk and the average of the micrometer

readings minus the initial reading was taken

as the depth of the indentation under load.

The deformations under racking load 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

chamiel of the deformeter, supported by two

steel plates, K in. thick, 4 in. square, rested along

the top of the specimen, with the steel angle

extending downward in the plane of the speci- men. Two pins passed snugly through holes

[3]
Figure 2.— Wall CI.

Typical specimen.

in the channel and into the top of the specimen.

A cUal micrometer was attached to a steel block

which was in contact with the floor plate of the

specimen at the stop. The spindle of the

micrometer was against the steel angle of the

deformeter. The gage length (distance from

the top of the specimen to the center of the

steel block) was 8 ft K in. The micrometer was graduated to 0.001 in., and readings were

recorded to the nearest division. This deformeter was used instead of the taut-wire mirrorscale device described in BMS2.

Thomas R. C. Wilson, of the Forest Products

Laboratory, Madison, Wis., cooperated with

the Bureau staff in this work by giving advice

and making suggestions on the technique of

testing wood structures.

The tests were begun April 10, 1939, and completed April 20, 1939, The sponsor's repre- sentative witnessed the tests. IV. MATERIALS

The information on materials was obtained

from the sponsor and from inspection of the

specimens, except that the Forest Products

Laboratory assisted by identifying the species

of wood in the framing, and the Engineering

Mechanics Section of the National Bureau of

Standards assisted by determining the moisture

content of the wood and the weight and trans- verse strength of the gypsum wall board.

1. Wood

Framing.—The wood for the framing was

identified as Douglas fir, Pseudotsuga taxijolia.

[4]
I No. 1 common, S4S (surfaced four sides), iu

' sizes % by 3?8 in. iKeby 2^^ in. (nominal 1% by

3 in), V/s by 2% in. (nominal 2 by 3 in), 1% by

3'% in. (nominal 2 by 4 in), and 1% by 7% in. (nominal 2 by 8 in)

I Ribbons.—Plywood, Douglas fir, % in. thick,

five-ply bonded with water-resistant glue.

! Douglas Fir Plywood Association "Plyscord"

grade. Washington Veneer Co., "Westboard."

Sheathing.—Plywood, Douglas fir, in. thick, three-ply, bonded with water-resistant

glue. Douglas Fir Plywood Association "Plysi cord" grade. Washington Veneer Co., "Westboard."

Subflooring.—Plywood, Douglas fir, % in. thick, five-ply, bonded with water-resistant glue,

i Douglas Fir Plywood Association "Plyscord"

I grade. Washington Veneer Co., "Westboard."

Flooring.—Red oak, by 2% in., plainsawed, select, tongue-and-grooved and endmatched.

j Shingles.—Red cedar, f8 in. long, 5 butts in

i VA in.. No. 1 "Certigrade" of the Red Cedar

< Shingle Bineau.

After each specimen was tested, one face was removed to expose the framing, and a sample

of the wood was taken from either a joist or a

I stud. Photographs w^ere made showing the

character of the wood in the framing, and also

; in the flooring on each floor specimen. Figures

! 2, 3, and 4 represent typical frames.

The moisture content of the wood (except

bridging and spacers) is given in table 2. Table 2.

Moisture content of the wood

[Ueterinined on the day the wall, partition, or floor specimen was tested]

AVood

Construction symbol

Moisture content »

Mini- mum

Alaxi- mumAverage

Framing, Douglas fir

Average __ _

(CI JCJ1 CK.

[CL..

Percent8

7

89

Percent

1916

1419

Percent

12

11

1113

12

Sheathing, Douglas fir plywood.

Subflooring, Douglas fir plywoodShingle'*, red cedar. . . . Floorins, red oak.

CI. .- CL.. CICL6

7 '><7

6

10

87

13

7

8

b <7

9

» Based on weight when dry.

*> "I-ess than'' «) symbol. An electric moisture meter was used for determining the moisture content. To calibrate

Figure 3.

Load-bearing partition CJ.

Typical specimen.

the meter for Douglas fir and red oak, 39 samples from the wall, partition, and floor frames

and 6 samples of the flooring were dried in an oven at 212° F. until the vveight was constant. The moisture content was the dift'erence between the initial weight and the weight when

ovendry, expressed as a precentage of the

weight when ovendry. The average value for the Douglas fir (framing) samples was 0.8 less than the average of the meter readings on the same samples. The average value of the redoak (flooring) samples was 0.6 less than the

[5]
average meter readings on the same samples.

Therefore, the moisture content of the Douglas

fir was obtained by subtracting 0.8 and the

moisture content of the red oak by subtracting

0.6 from the average of the meter readings.

The results were rounded to the nearest whole

number. The moisture content was determined on each piece of framing and on six pieces of flooring from each specimen.

The average uncorrected meter reading on

six shingles per specimen was taken as the

moisture content of the shingles. On the plywood sheathing and subflooring the determination was made by drying one sample from each

specimen in an oven until the weight was

constant.

2. Wallboard

Gypsum wallboard, 12 ft 0 in. long, 4 ft 0 in. wide, % in. thick, weight 2,000 lb/1,000 it\ The

wallboard was gypsum plaster containing

graded cork and reinforced on each face by a

sheet of paper. The plaster was 93 percent

of gypsum plaster and 7 percent of graded

cork, by weight. On one face the paper was

manila, buff, 0.021 in. tliick, weight 85 lb/1,000

ft-; on the other face, gray, 0.021 in. thick,

weight 75 lb/1,000 ft". The longitudinal edges

of the buff face were rabbeted IK in. wide and

0.025 in. deep.

The transverse strength of the wallboard,

determined in accordance with Federal Specification SS-W-51a, Wallboard; Gypsum, was

189 lb loaded across the surface fibers of the

paper, and 50 lb loaded parallel to the siu-face

fibers. The wallboard complied with the re- quirements of the specification for weight and

strength. Kelley Plasterboard Co., "Kelley

Cork-Gypsum Wallboard."

3. Nails

All the nails except the cut flooring nails were made from steel wire. The description is given

in table 3. 4. Sheathing Paper

Asphalted paper.—Felt, asphalt-saturated,

weight 15 lb/100 ft^; rolls, width 3 ft 0 in., area 432 ft-. Lloyd A. Fry & Co.

Rosin paper.—Red paper, rosin-sized, weight

4 lb/100 ft^; rolls, width 3 ft 0 in., area 500 ftl

Sears, Roebuck & Co., Catalog No. 48 H M

3007.

Table 3.

Description of nails

Type Size Length

steel Wire Gage

Di- ameter

U.S.

std. Gage

Thickness

P'inish

Common,

,

DoDq

Penny

68

10

1620

8

in.1%

2%

2Vs m

No.

13

119

7

in.

0. 0915

. 113

. 1205

. 1483

. 177

No. in. Cement-coated. Do.

Do.

Do.

Do.

Blued.

Zinc-coated.

Do

Do

Flooring. Plasterboard."

Shingle

12 0. 1072

13

12

.0915

.1055

" Head diameter Vie in.

5. Staples

Tacker staples, formed of sheet steel. No. 25

U. S. Std. Gage (0.0214 in. thick), 0.05 in. wide;

staple, Yu in. wide, Yie in. long, tinned.

6. Glue

Water-resistant glue, I. F. Laucks, Inc., No. 888.

7. Joint Filler

The filler was a mixture of casein glue, clay,

and mica; casein, minimum 10 percent, by

weight. Kelley Plasterboard Co., Inc., "Kelley Joint Filler."

8. Tape

Cotton tape, 2 in. wide, approximately 0.006

in. thick, thread count 44 by 40. Kelley Plasterboard Co., Inc., "Kelley Cloth Tape."

V. WALL CI

1. Sponsor's Statement

Wall CI was a prefabricated wood frame

having plywood sheathing, sheathing paper, and

wood shingles as the outside face and gypsum

wallboard as the inside face. The specimens were not painted.

The price of this construction in Washington,

D. C, as of July 1937, was $0.335/ft2.

(a) Four-Foot Wall Specimens

The 4-ft wall specimens shown in figure 5 were 8 ft 1%6 in. high, 4 ft 0 in. wide, and 5%

in. thick. Each specimen was a wood frame to wliich the faces were fastened. The frame consisted of three full-sized studs, A, and one half- sized stud, B, fastened to a floor plate, C, and

[6]
Figure 4.

Floor CL.

Typical specimen.

218547°—40 2

Figure 5.

Four-foot wall specimen CI

.

A. full-sized studs; 7?, half-sized stud; C, floor plate; D, top plate: E, i)ly- wood ribbon; F, plywood sheathing; G, sheathing paper; H, wood

siiingles; /, wallboard; spacers.

a top plate, D, by nails. The joint between the center stud and the half-sized stud represented

the joint between two adjacent prefabricated

sections when erected in a house. A plywood

ribbon, E, was fastened to the studs at midheight. The outside face consisted of plywood

sheathing, F, sheatlihig paper, G, and wood

sliingles, H. The inside face consisted of two

sheets of gypsum wallboard, /. The overhanging edges of the faces were supported by

spacers, J.

Full-sized studs.—The full-sized studs. A,

were Douglas fir, 1% by 3% in., 7 ft lOKs in. long, spaced 1 ft 4 in. on centers. The inside

edges of the studs were dadoed (notched) % by

3?8 in. at midheight.

Half-sized stud.—The half-sized stud, B, was

Douglas fir, % by 3% in., 7 ft 11 Me in. long,

dadoed % by Sji in. at midheight, and fastened

to the center stud by 8d common nails spaced

about 1 ft 0 in.
Floor plate and top plate.—The floor plate, G,

and the top plate, D, each consisted of two

pieces of Douglas fir, l^g by 3% in., 2 ft 0 in. long, with a joint on the center full-sized stud.

Each piece was fastened to an outer stud by

two 20d common nails driven through the

plate into the stud (not toenailed). One piece was notched % in. wide by K in- deep, fitting over the half-sized stud, to which it was fas- tened by two lOd common nails tlirough the

piece into the half-sized stud. The other piece was fastened to the center full-sized stud by

two 16d common nails through the piece into

the stud (not toenailed).

Plywood ribbon.—The plywood ribbon, E,

consisted of two pieces of '%-m. Douglas fir plywood, 3% in. wide and 2 ft 0 in. long, with a

joint on the center full-sized stud. The grain

of the outer plies was longitudinal. The rib- bon fitted flush into the dadoes in the studs and was fastened to each stud by two 6d common

nails. Sheaihing.—The sheathing, F, was two pieces

of ^16-in. Douglas fir plywood, 1 ft 11 ^^(e in. wide and 8 ft 0 in. long, the grain of the outer

plies being longitudinal (vertical). There was

a vertical joint on the center stud with }i in. clearance between the edges. The plywood was fastened to the outer studs, the floor plate,

and the top plate by 6d common nails spaced

6 in. One piece of sheathing was fastened to the center full-sized stud by 6d common nails

spaced 4 in. and to the half-sized stud by 6d

common nails spaced 6 in. The other piece was fastened to the center stud by 6d common

nails spaced 6 in. Sheathing paper.—The sheathing paper, G,

consisted of three sheets of asphalted paper,

3 ft 0 in. by 4 ft 0 in. The sheets were laid transversely over the sheathing with two 6-in. laps and were fastened to the sheathing along

the laps and at the ends of the specimen by

staples, spaced about 8 in., which were driven

through both sheets at the laps.

Shingles.—The shingles, H, were red cedar,

18 in. long, exposed 8 in. to the weather, and

fastened at midlength to the sheathing by 1)2- m. shingle nails, two nails through each shingle.

Wallboard.—The wallboard, /, was two sheets

of gypsum wallboard, in. thick, 4 ft 0 in. square, with a transverse joint between the

rabbeted edges on the plywood ribbon. The

wallboard was fastened to the ribbon by glue

and by l^g-in. plasterboard nails spaced 6 in., to the full-sized studs by l^s-in. plasterboard

nails spaced 8 in., and to the top plate and floor plate by l}^-in. plasterboard nails % in. from

the edge of the board, spaced 6 in. The wallboard was not fastened to the half-sized stud.

The joint was calked with filler, covered with

2-in. tape, and allowed to set. More filler was

then applied over the tape, bringing the surface

flush with the wallboard.

Spacers.—The spacers, J, along the over- hanging edges of the faces, were Douglas fir,

1/s by 3/8 in., 4 in. long, and each was fastened

to the wallboard by two l^s-in. plasterboard

nails and to the sheathing by two 6d common

nails passing through the wallboard and sheathing into the spacer. Spacers are not used in a house.

(6) Eight-joot Wall Specimens

The S-ft wall specimens shown in figure 6 were 8 ft 1^6 in. high, 8 ft 0 in. face width, and

in. thick. The specimens were similar to the 4-ft specimens, except there were seven

full-sized studs spaced 1 ft 4 in. on centers,

and two half-sized studs, one fastened to the

center stud and one to an edge stud. A full- sized stud at each edge extended one-half its thickness beyond the faces. The width overall was 8 ft 1% in. Sheathing.—The sheathing was two pieces of plvwood, 8 ft 0 in. by 4 ft 0 in., the grain of the outer plies being longitudinal (vertical). There was a vertical joint on the center stud. The

plywood was fastened to the outer studs, the

floor plate, and the top plate by 6d common nails

spaced 6 in. One piece of sheathing was fastened

to the center full-sized stud by 6d common nails

spaced 4 in. and to the half-sized stud by 6d

nails spaced 6 in. ; and the other piece to the

center stud by 6d nails spaced 6 in. Wallboard.—The wallboard consisted of three

sheets of gypsum wallboard: one piece, 8 ft 0 in. by 4 ft 0 in., extending over the entire width;

and two pieces, 5 ft 4 in. by 4 ft 0 in. and 2 ft 8 in. by 4 ft 0 in., with a longitudinal (vertical) joint over a stud 2 ft 8 in. from the edge of the face. The full-width piece covered the upper half of one specimen and the lower half of the others.

[81
Figure 6.

Eight-foot wall specimen CI.

A, full-sized studs; B, half-sized stud; C, floor plate; D, top plate; E, ply- wood ribbon; F, plywood sheathing; G, sheathing paper; //, wood

shingles; /, wallboard.

There was a horizontal joint at midheight over

the ribbon. The wallboard was fastened to the floor plate, the top plate, and the edge studs

by iK-in. plasterboard, nails in. from the edge

of the boards, spaced 6 in. It was fastened to the ribbon by glue and by 1%-in. plasterboard

nails spaced 6 in., to the stud at the vertical

joint by 1%-in. nails spaced 6 in., and to the

remaining full-sized studs by l/g-in. nails spaced

8 in. It was not fastened to the half-sized

studs. Both joints were calked with filler and

covered with tape.

(c) Comments

Wall sections are manufactured in widths

wliicli are luultiples of 1 ft 4 in. The actual

width depends on the size and location of openings and on the location of partitions. Usually the joints are at the edges of openings

and at mtersecting partitions. The sections

are full story height, the usual ceiling height

being 8 ft.

The prefabricated sections consist of the

wood frame, plywood sheathing, and ribbon.

They are assembled without the use of power

equipment by raising into a vertical position on the subfloor and then sliding into place.

They are fastened to the floor by two 16d nails

between each pair of studs, driven through the

floor plate into the headers in the floor. At a

joint, the edge stud, the top plate, the ribbon,

and the sheathing are nailed to the edge stud

of the adjacent section. The wall sections are

joined at corners by a special unit.

At the intersection of a wall and a partition

a half-sized stud is nailed to a stud in the wall

OTul the partition is fastened to the half-sized

stud.

Openings are framed for conventional sizes of doors and windows, which are put in place

after the sections are assembled.

Exterior and interior finishes are applied

after the frames for the openings are in place.

Exterior finishes may be wood siding, shingles,

[9]
Figure 7—Wall specimen CI-Cl

load. under compreasive

stucco, or brick veneer. The interior finish is usually wallpaper or paint on gypsum wallboard. Thermal insulation may be placed

between the studs. This space can also be

used for pipes, ducts, and conduits.

2. Compressive Load

Wall specimen CI-Gl under compressive load

is shown in figaire 7. The results for speci- mens CI-Cl, C2, and C3 are given in table 4

and in figures 8 and 9. The speed of the movable head of the testing

machine under no load was adjusted to 0.072

in./min. The lateral deflections shown in figure

—

1

« K

o-o

—•» —o- — ( >o

< »-•

—O-i )

•

/

/ -WW—W'^-'

411

J

' /

h

CI 0 0,1 0.2 0.5

shorfeninci in. Figure 8.

Compressive load on wall CI.

Load-shortening (open circles) and load-set (solid circles) results for specimens CI-Cl, C2, and CS. The load was applied 1.21 in. (one

third the thickness ot the frame) from the inside surface ol the studs. The loads are in kips per foot of actual width of specimen.

0.1 0,2 0.3

/aferal deflection in. Figure 9. —Compressive load on wall CI.

Load-lateral deflection (open circles) and load-lateral set (solid circles) results for specimens CI-Cl, C2, and CS. The load wa;; applied 1.2] in. (one-third the thickness of the frame) from the inside surface of the studs. The loads are in kips per foot of actual width of specimen. The deflections and sets are for a gage length of 8 ft 0 in., the gage length

of the deflectometers.

[10]
Table 4.

Structural properties of wall CI and load-bearing parliiion CJ

[Weight: Wall CI, 5.46 lb/ft 2; load-bearing partition CJ, 5.421b/ft21

Construction symbol

Load

Compressive "> Transverse •> Concentrated Impact >> Racking

Specimen Maximum Specimen Ma.ximum Specimen Maximum Specimen

Maximum

height

of drop

Siiccimen Maximum

loa^l

CI

( CI

" Kipslft

4.22

7.57 5.98

Tl MP345

272 342

PI

lb 192

18fi 192

//.. - ft

<i 10. 0

10.

0

d 10.0

HI

" Kipslft

1.37 1.20

1. 18

\ C3 T2 pe IB - RB

Average.

[ CS T3 PS IS R3

5. 92 320 190 <l 10.0 1.25

CI - n - 237 225

169

Pi « 1, 000

1, 000

950 U ---- ' 10.0 9.0

' 10.0 |::::::::::: T5.. P5. IS

Average..

T6 P6 16.-

210

CJ.

1 CI 4. 90

6. 00

5. 65

Tl 107 125 122PI 181 175

210

/; 8.0

6.5

6.0

Rl 0.80

.80

.83

{ eg T2 P2 ___ 72 R2

Average

[ CS T3 PS IS R3

5. 52 138 189 6.8 0. 81

3 The compressive loads were applied 1. 21 in. (one-third the thickness of the frame) from the inside surface of the studs,

b Span 7 ft 6 in.

men. These cracks were observed at a load of

300 Ib/ft^ on specimen Tl , 200 Ib/ft^ on specimen T2, and 175 Ib/ft^ on specimen T3. The

deflections of the specimens under these loads were 2.03, 1.25, and 1.04 in., respectively.

Under the maximum load the center stud of

specimen Tl ruptured at midspan, and as the

deflection increased without an increase in load

both outer studs ruptured. In specimens T2

and T3 under the maximum loads two studs

ruptured near midspan and the top plate and

floor plate separated from the studs and sheathing.

In specimen T4 under a load of 148 Ib/ft^, in T5 under 194 Ib/ft^, and in T6 under the

maximum load, all the studs split along the

grain, beginning at the dadoes at midheight.

The force exerted by the split studs ruptured

the gypsum wallboard at the transverse joint.

Under the maximum load on each specimen aU

the studs ruptured either partially or completely.

In each stud the rupture began at the dado.

4. Concentrated Lo.\d

Concentrated-load test results are presented

in table 4 and in figure 12 for wall specimens

CI-Pl, P2, and PS, loaded on the inside face,

and in figure 13 for specimens CI-P4, P5, and

P6, loaded on the outside face.

" A Kip IS 1, IIUU ID.

d Test discontinued. Specimen did not fail. No studs broken.

» Test discontinued. Specimen did not fail, the shingle split.

' Test discontinued. One or more studs ruptured.

9 were plotted to the right of the vertical axis

for deflections of the specimen toward the outside face. Under a load of 4.0 kips/ft on specimen CI

the studs crushed mto the top plate at the

inside surface of the wood frame. The studs

crushed mto the plate in specimen C2 under

a load of 3.5 kips/ft. and in specimen C3 under

a load of 5.5 kips/ft. Under loads of 4.0, 7.0,

and 5.5 kips/ft, respectively, the gypsum wallboard separated at the top of the studs. Under

the max-imum load on each specimen the top

plate split along the gram and crushed at the

inside surface of the studs.

3. Transverse Load

The transverse-load test results are shown in table 4 and in figure 10 for wall specimens

CI-Tl, T2, and T3, loaded on the inside face,

and in figure 11 for wall specimens CI-TJi., T5,

and T6, loaded on the outside face. The speed of the movable head of the test- ing machine under no load was adjusted to 0.14 in./min.

As the load was uacreased the nails tilted under the shearing forces exerted by the gypsum

wallboard, and small circular cracks appeared

around the head of each nail. This was particularly pronounced near the ends of the speci-

[11]
300

^200

^ 100

• —• •

c

• • o c

o

160

0 0.5 1.0 /J 2.0

deflecflon in. Figure 10.—Transverse load on wall CI, load applied

to inside face.

Load-deflection (open circles) and load-set (solid circles) results for specimens CI-Tl, T2, and T3 on the span 7 ft 6 in.

I

I

/20

80

40

c O

r

1

L

m

1

CI-I 0 0.04 0.08 0./2 0.16 indenhfion in. Figure 12.— Concentrated load on wall CI, load applied

to inside face.

Load-indentation (open circles) and load-set (solid circles) results for specimens CI-Pl, P2, and PS.

Figure 11.

/ 2 5

defleciion In

-Transverse load on wall CI, load applied

to outside face.

1000

^ 800

o

600

400

200

1 » 0

1 —

-O-i — -o—

<

^ •J

I

r

to- —o-

•«

/

•-

/o-

-I —

c

o

)

-o )—

» •

/ L

1

—

o

L

C/-4

Load-deflection (open circles) and load-set (solid circles) results for specimens CI-TIf, T6, and T6 on the span 7 ft 6 in.

0 0.4 08 1.2 1.6 indenfafion in. Figure 13.—Concentrated load on wall CI, load applied

to outside face.

Load-indentation (open circles) and load-set (solid circles) results for specimens Cl-Pi, P.i, and P6.

12
The concentrated loads were applied to the

inside face of specimens CI-Pl, P2, and P3 on

the gypsum wallboard midway between two

studs and about IJo ft from one end of the speci- men. Under the maximum load on each speci- men the disk punched through the wallboard.

The concentrated loads were applied to the

outside face of specimens CI~P4, PS, and P6' on a shingle about 1^ ft from an end of the

specimen. The load was applied midway between studs on specimens P4 and P6 and 1 % in. from a stud on specimen P5. In specimen P4

the shingle spUt along the grain at one edge of the disk under a load of 800 lb, and in speci- mens Pd and P6 under a load of 750 lb. Under

the maximum load on specimen P6 the disk

punched through the shingle and the plywood

sheathing. In specimens P4 and P6 the sets

after a load of 1,000 lb were 0.39 and 0.23 in., respectively.

5. Impact Load

Impact-test results are shown in table 4 and

in figure 14 for wall specimens CI-Il, 12, and

IS, loaded on the inside face, and in figure 15

for wall specimens CI-I4, 15, and 16, loaded on the outside face. The impact loads were applied to the center

of the inside face of specimens CI-Il , 12, and IS,

the sandbag striking the gypsum wallboard

directly over the plywood ribbon and the centei

stud. The effects are given in table 5.

Table 5.

Effects of impact load on wall CI, load applied

to the inside face

Description of effects on

loaded (gypsum wall- board) face

Specimen // Specimen 12 Specimen IS

Height

of drop

Deflec- tion

Height

of drop

Deflec- tion

Height

of drop

Deflec- tion

ft in. ft in. ft in. Nails began to pull from

studs 2.0 0.82 1.0 0. 61 1.0 0. 58 Wallboard cracked where

the sandbag struck 6.0 1.62 6.5 1. 71 6.5 1.81 Wallboard ruptured lon- gitudinally between

studs 8.5 2. 10 8.5 2.07 Wallboard ruptured

transversely along the

2.31 joint at midspan 8.5 2.07 8.5

After the 10-ft drop on specimens II, 12, and

IS the sets were 0.16, 0.14, and 0.19 in., respectively. No studs were broken, and the face not

loaded (shingles) was undamaged.

10

8

4

2

1

(y 1 r

-m-—

1m —

'

fo

1 •

1 • —

•

• •

1• '

1h

C/-/

I 2

deflecflon in. 3

Figure 14.

Impact load on wall CI, load applied to inside face. Height of drop-deflection (open circles) and height of drop-set (solid

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

10

8

I'

4

2

I—•—

1

—•

1—o—

1

—

•

c )

•—o-(

-G—

C

) —o- ^

' o-

/

1

1l7

V CI-4 "0 2 4 6

defiedion in. Figure 15.

Impact load on wall CI, load applied to outside face.

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

circles) results for specimens CI-IJ,, 15, and 16 on the span 7 ft 6 in.

[13]
The impact loads were applied to the center

of the outside face of specimens 01-14, 15, and

16, the sandbag striking the shingles directly over the center stud. The effects are given in

table 6.

Table 6.

Effects of impact load on wall CI, load applied to the outside face

Description of efiects

Specimen H Specimen IB Specimen 16

Height

of drop

Deflec- tion

Height

of drop

Deflec- tion

Height

of drop

Deflec- tion

Face not loaded (gypsum

wallboard)

:

Longitudinal crack

along center stud at ft in. n in. ft in. midspan.. 1.5 0. 75 2.5 1.13 2.0 0. 94 Nails began to pull from

studs 2.0 .92 2.5 1. 13 2.5 1.12 Wallboard ruptured

longitudinally along

center stud at midspan 3.5 1.50 Wallboard separated 3

in. or more from studs

at midspan 4.0 2. 09 5.0 1.90 Face loaded: Shingles

split longitudinally

along a stud 7.0 2. 66 7.0 5. 70 9.0 3. 98 Studs: Center full-sized stud and half-sized stud

split along the grain, beginning at the dado. 4.0 1.66 5.0 2.37 5.5 2.20 Rupture of either one or two studs..__ _ . _ 8.0 3. 95 6.0 3. 78 Rupture of all studs, sandbag passed

through specimen 9.0

The maximum height of drop on specimen

CI-I6 was 9.0 ft. After the 10-ft drop on speci- mens Cl-IJi and 16 the sets were 2.50 and 0.62

in., respectively.

6. Racking Load

The racking-load test results for wall speci- mens CI-Rl, R2, and R3 are shown in table 4 and in figure 16. Eacking loads were applied by means of a hand-driven pump, and the speed could not be

closely controlled. The load was applied only

to the top plate, and the stop was in contact

only with the floor plate at the diagonally

opposite corner of the specimen.

Under a load of 1.0 kip/ft on specimens CI-Rl

and R2 there was noticeable tearing of the

plasterboard nails through the edges of the

gypsum wallboard along the top plate, along

the upper portion of the stud at the unloaded

edge, and along the lower portion of the stud

at the loaded edge of the specimen. Under a load of 0.8 kip/ft on specimen R3 the nails began

1.2 ^

1,0

0.8

-5 0.6

0.2

0

w

/-^

r\

r\ \J \J

\ C—u»-

r C L

T ^ •

\C\ 3

CI 0 0.4 0.8 1.2

deformafion in./Sff

Figure 16.Racking load on wall CI.

Load-deformation (open circles) and load-set (solid circles) results for specimens CI-Rl, RS, and R3. The loads are in kips per foot of actual width of specimen.

to tear through the edges of the wallboard

along the top plate and the edge studs. Under

the maximum loads the wallboard separated

from the edge studs and the top plate, and the

nails in the plywood sheathing bent, some pulling from the studs and the top plate. There was about K-in. vertical displacement between

the pieces of sheathing at the joints. The

wallboard on specimens R2 and R3 cracked near the center of the specimen and the vertical

joint ruptured, tearing the tape.

VI. LOAD-BEARING PARTITION GJ

1. Sponsor's Statement

Load-bearing partition GJ was a wood frame

with faces of gypsum wallboard. It was similar to wall GI except that both faces were wall- board, not one face. The specimens were not

painted.

The price of this construction in Washington,

D. C, as of July 1937, was $0.252/ft^

(a) Four-foot Partition Specimens

The 4-ft partition specimens shown in figure

in. high, 4 ft 0 in. wide, and 4^

Each specimen was a wood frame to

17 were 8 ft 1%^

in. thick.

[14]
Figure 17. —Four-foot load-hearing partition

specimen CJ

.

A, full-sized studs; B, half-sized stud; C, floor plate; D, top plate; E, plywood ribbon; F, wallboard; G, spacers.

'I which faces were fastened. The frame conj sisted of three full-sized studs, A, and a

half-sized stud, B, fastened to a floor plate, C,

and a top plate, D, by nails. The jomt between

the center stud and the half-sized stud repre- sented the joint between two adjacent prefabricated partition sections when erected in a house,

li Two plywood ribbons, E, were fastened to the

I studs at midheight. Each face consisted of two

i sheets of gypsum wallboard, i^. The overhanging

edges of the faces were supported by spacers, G. Full-sized studs.—The full-sized studs. A,

were Douglas fir, 1% by 3% in., 7 ft lOKs in- long, spaced 1 ft 4 in. on center. Both edges

of the studs were dadoed % by 3% in. at midheight.

Half-sized stud. —The half-sized stud, B, was

Douglas fir, % by 3% in., 7 ft llKe in. long,

dadoed on both edges % by 3% in., at midheight,

and was fastened to the center stud by 8d com- mon nails spaced about 1 ft 0 in.

Floor plate a,nd top pl.aU. The floor plate,

and the top phite, IJ, each consisted of two

pieces of Douglas fir, 1% by 3^ in., 2 ft 0 in. long,

with a joint on the center full-sized stud. Each

piece was fasten(!d to an outer stud by two 20(1 common nuils driven through the plate into the

stud (not toenailed). One piece was not(;lied

% in. wide by K in. deep, fitting over the lialf- sizcd stud, to wliich it was fastened hy two lOd

common nails through the piece into tlie liaif- sized stud. The other piece was fastened to the center full-sized stud by two IGd common nails

through the piece into the stud (not toenailed).

Plywood ribbons. —Each plywood ribbon, E,

consisted of two pieces of %-iD.. Douglas fir plywood 3% in. wide and 2 ft 0 in. long, with a joint on the center full-sized stud. The grain of the

outer plies was longitudinal. The ribbons fitted flush into the dadoes in the studs and were

fastened to each stud by two 6d common nails. Wallboard.—The wallboard, F, on each face, was made up of two sheets of gypsum wallboard, )^ in. tliick, 4 ft 0 in. square, with a transverse joint between the rabbeted edges on

the plywood ribbon. The wallboard was fas- tened to the ribbon by glue and by 1/^-in. plasterboard nails spaced 6 in., and to the full- sized studs by 1%-in. plasterboaz-d nails spaced

8 in. It was fastened to the floor plate and

top plate by l^s-in. plasterboard nails spaced 6

in., and to % in. from the edge of the board.

It was not fastened to the half-sized studs.

The joint was calked with filler, covered with

2-in. tape, and allowed to set. More filler was

then applied over the tape, bringing the surface

flush with the wallboard.

Spacers.—The spacers, G, along the over- hanging edges of the faces, were Douglas fir, 1^8 by 3/8 in., 4 in. long, fastened at each side to the wallboard by two IJs-in. plasterboard nails. Spacers are not used in a house.

(b) Eight-Foot Partition Specimens

The 8-ft partition specimens shown in figure

18 were 8 ft iKe in. high, 8 ft 0 in. face widtii,

and 4% in. thick. The specimens were similar

to the 4-ft specimens, except that there were

seven full-sized studs 1 ft 4 in. on centers and

two half-sized studs, one fastened to the center stud and one to an edge stud. A full-sized stud at each edge extended one-half its thick-

[15]
Figure 18.

Eight-foot load-hearing partition

specimen CJ.

A, full-sized studs; B, half-sized stud: C, floor plate; D, top

plate; E, plywood ribbon; F, wallboard.

ness beyond the faces. The width overall was

8 ft 1% in. Wallboard. —The wallboard on each face consisted of three sheets of gypsum wallboard ; one

piece, 8 ft 0 in. by 4 ft 0 in., extending over the

entire width; and two pieces, 5 ft 4 in. by 4 ft 0 in. and 2 ft 8 in. by 4 ft 0 in., with a longitudinal (vertical) joint over a stud 2 ft 8 in. from

the edge of the face. The full-width pieces cov- ered the upper half of one specimen and the

lower half of the others. There was a horizontal joint at midheight over the ribbon. The

wallboard was fastened to the floor plate, the

top plate, and the edge studs by 1/8-in. plasterboard nails in. from the edge of the board,

spaced 6 in. It was fastened to the ribbon by

glue and by IJHnch plasterboard nails spaced 6

in., to the stud at the vertical joint by l/s-in. nails spaced 6 in., and to the remaining full- sized studs by 1/8-in. nails spaced 8 in. It was

not fastened to the half-sized studs. Both

joints were calked with filler and covered with

tape.

(c) Comments

In a house of tliis construction the loadbearing partitions are assembled at the same

time as the wall sections and in like manner.

Adjacent partitions are joined by nailing

through the edge studs, the overlapping top

plate, and plywood ribbons. The frames for doors are placed and the interior finish is apphed

after the sections are assembled.

2. Compressive Load

The results of compressive tests for loadbearing partition specimens CJ-Cl, C2, and C3

are shown in table 4 and in figures 19 and 20. The speed of the movable head of the testing

machine under no load was adjusted to 0.072

[16]
CD

<2>

I

• i —•—

e

• o d • m o c ) o

1

1

po

/

• /J

O

/

L J

5horfenin(^ in.

Figure 19.- -Compressive load on load-bearing partition CJ.

Load-shortening (open circles) and load-set (solid circles) results for specimens CJ-Cl, C2. and CS. Load was applied 1.21 in (one-tliird the thickness of the frame) from the edge of the studs nearer the load line. The loads are in kips per foot of actual width of specimen.

in./min. The lateral deflections shown in fig- ure 20 were plotted to the right of the vertical

axis for deflections of the specimen toward the

"outside" face (the face which is the farther

from the load line).

Under a load of 4.5 kips/ft on specimen CJ-Cl

the studs crushed into the top plate at the

''inside" surface of the wood frame. The studs

in specimen C2 crushed into the top plate under

a load of 5.0 kips/ft, and in specimen C3 under

a load of 5.5 kips/ft. Under the maximum load on each specimen there was further local crushing of the top plate at the "inside" edges of the

studs, causing the plate to rotate. The gypsum

wallboard and the studs were undamaged.

3. Transverse Load

The results of the transverse-load tests are shown in tables 4 and 7 and in figure 2 1 for loadbearing partition specimens CJ-Tl, T2, and T3.

The speed of the movable head of the testing

machine under no load was adjusted to 0.14

in./min.

A

O

6

4

3

2

I

• —

1

» -i

1 J

T7

1 c>-—

1

> o— o

—

<

> O—

(

>—

Tr

T

ay

0 0,2 OA 0.6

lateral deflecfion in. Figure 20.-- Compressive load on load-bearinq parlition CJ.

Load-I ll cral deflection (open circles) and load-lateral set (solid circles) results for specimens CJ-Cl, Ci, and C3. Load was api)lie<l 1.21 in. (oni -lhird the thickness of the frame) from the edge of the studs nearer

tlic load line. The loads are in kijjsper foot of actual width of specimen. The deflections and sets are for a gage length of 8 ft 0 in., the gage

length of the deflectometers.

160

120

I 80

(n

I 40

• o

• o

• o

/ ••— opo

m

\

1 J

CJ

0 05 1.0 1.5 deflecfion in. Figure 21.

Transverse load on load-bearing parlition CJ.

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

17]
Table 7.

Effects of transverse load on load-hearing

partition C.J

Specimen Spec men Specimen

Tl Ti T3

Description of eiiects De- De- De- Load flec- Load flec- Load flec- tion tion tion mm 2 in. Z5//; 2 in. mn 2 in. One or more studs split along

the grain, beginning at the

105 0.76 97 0.81 105 0. 84 Face not loaded, gypsum wall- board ruptured transversely near midspan, splitting the studs further _ IfiO 1.7.5 124 120 1.04

All studs either ruptured or

split further; maximum load. The wallboard on the loaded

face was undamaged.- 167 125 122

4. Concentrated Load

The concentrated-load test results are shown

in table 4 and in figure 22 for load-bearingpartition specimens CJ-Pl, P2, and P3.

The concentrated loads were applied to one

face of the specimens on the gypsum wallboard

midway between studs and about IK ft. from

one end. Under the maximum load on each

specimen the disk punched through the wallboard .

200

160

120

80

40

«

—°n

• c o

• < -/o

o > 7

/•h

CJ 0 0.04 0.08 0.12

Indeniafion in. Figure 22.

Concentrated load on load-hearing partition CJ.

Load-indentation (open circles) and load-set (solid circles) results for specimens CJ-Pl, P$, and rs.

7

6

I.

O 7

I

0

Figure 23.-

•

•• «

j

1 9

•

o

o o —

m

/

c ocK)

/

o

/ »• T«

rfo -<Ay *

m Ad

1 1

•

1 i—

•

• JP

CJ

0 12 5

deflecfion In. - Impact load on load-hearing partition CJ.

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

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

5. Impact Load

The impact-test results are shown in table

4 and in figure 23 for load-bearing partition

specimens CJ-Il, 12, and 13.

Table 8. -Effects of impact load on load-hearing partition

CJ

Description of effects

Specimen 11 Specimen 12 Specimen 13

Height

of drop

Deflec- tion

Height

of drop

Deflec- tion

Height

of drop

Deflec- tion

ft. in. ft. in. in. Both faces: Nails in gyp- sum wallboard began to pull from the studs. . . . 2.0 0. 92 L5 0. 74 2.0 1.05 Face not loaded: Wallboard cracked along center stud LS .76 3.0 1.21 1.5 0. 84 Wallboard separated 3

in. or more from studs

at midspan ... _ . 5.5 2. 12 6.0 2. 17 3. 5 1. 61 Face loaded: Wallboard cracked where

the sandbaL' struck. _ 5.5 2. 12 5.0 2. 17 4.5 2. 80 Wallboard ruptured where

the sandbag struck 6.0 2. 59 6.0 3.40 5.0 5. 86 Studs: One or more studs split along the grain, begin- ning at the dado 6.0 2.59 5.5 2.58 3.0 1.42 One or more studs rup- tured at the dado 7.5 5. 61 6.5 4.0 2.00 Sand bag passed through specimen; maximum

height of drop 8.0 6.5 6.0

The impact loads were applied to the center

of one face, the sandbag striking the gypsum

[18]
Figure 24.

Load-bearing -partition specimen (2J-R2 under racking load.

wallboard over the plywood ribbon and the center stud. The effects are given in table 8,

6. Racking Load

Load-bearing partition specimen CJ-R2 under

racking load is shown in figure 24. The results for specimens CJ-Rl, R2, and R3 are presented

in table 4 and in figure 25. The racking loads were applied by means of a hand-driven pump, and the speed could not

be closely controlled. The load was applied

only to the top plate, and the stop was in contact only with the floor plate at the diagonally

opposite corner of the specimen.

Under a load of 0.60 kip/ft on specimen

CJ-Rl the plasterboard nails tore noticeably

through the edges of the gypsum wallboard on

both faces along the top plate and along the

upper portion of the stud at the unloaded edge.

In specimen R2 under a load of 0.70 kip/ft the

nails began to tear through the edges of the

wallboard along the upper portion of the stud

at the unloaded edge and along the lower portion of the stud at the loaded edge. In specimen R3 under a load of 0.70 kip/ft the nails began to tear tlu'ough the wallboard along the

stud at the unloaded edge.

Under the maximum load on each specimen

the nails in the edge studs and top plate tore further through the edges of the wallboard,

and the frame had moved 1 to 2 in. relative

to the faces.

VII. NON-LOAD-BEARING

PARTITION CK

1. Sponsor's Statement

Non-load-bearing partition CK was a wood

frame with gypsum wallboard as both faces. It was similar to load-bearing partition CJ,

except that there were foiu' 2- by 3-in. studs,

not three 2- by 4-in. studs and one half-sized

stud. The specimens were not painted.

[19]
I

0 0,4 0,8

deformaiion in.jSfi

Figure 2b.— Racking load on load-bearing pa/iition CJ.

Load-deformatioii (open circles) and load-set (solid circles) results for specimens CJ-Rl, RS, and RS. The loads are in kips per foot of actual width of specimen. The price of this construction in Washington,

D. C, as of July 1937, was $0.242/ft-.

These specimens did not represent portions

of the partitions from a completed house

because, in a representative specimen with

studs spaced 16 in., there should be but three

studs or the equivalent, as shown in figures 1 and 2 of BMS2.

(a) Description of Specimens

The partition specimens shown in figure 26 were 8 ft 1%6 in. high, 4 ft l^s in. wide, and 3% in. thick. Each was a wood frame to which the

faces were fastened. The frame consisted of

four studs. A, a floor plate, B, and a top plate, C. Two plywood ribbons, D, were fastened

to the studs at midheight. Each face consisted

of two sheets of gypsum wallboard, E.

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

by 2% in., 7ft lOYu in. long, spaced 1 ft 4 in. on centers. Both edges of the studs were dadoed /8 by 3% in. at midheight.

Floor plate and top plate.—The floor plate,

B, and the top plate, C, were Douglas fir, 1%

by 2% in., 4 ft l/s in. long. The plates were

fastened to the studs by two 16d common nails

driven through the plates into each stud (not

toenailed). I Plywood ribbons. —The plywood ribbons, D, were %-in. Douglas fir plywood, 3% in. wide,

4 ft 1% in. long, fitting flush into the dadoes in the studs and fastened to each stud by two 6d ' common nails. Wallboard.—The wallboard, E, on each face, was two sheets of gypsum wallboard, % in. thick, 4 ft 0 in. square, with a transverse joint

between the rabbeted edges on the plywood ( ribbon. The wallboard was fastened to the ' ribbon by glue and by l}^-in. plasterboard > nails spaced 6 in., and to the two ianer studs

by IJ-^-in. plasterboard nails spaced 8 in. It was fastened to the floor plate, top plate, and

outer studs by 1 %-'m. plasterboard nails in. from

the edge of the board, spaced 6 in. The joint was \ calked with filler, covered with 2-in. tape, and

allowed to set. More filler was then applied ' over the tape, bringing the surface flush with

the wallboard. "

Figure 26.

Non-load-bear ing partition CK.

A, full-sized studs; B, floor plate; C, top plate; D, plywood ribbon; E,

wallboard.

[20]
(6) Comments

Non-load-bearing partition sections are made

in one piece. They are placed after the floor,

wall, load-bearing partition, and ceiling sections have been assembled and are fastened by

nailing through the plates and edge studs.

2. Concentrated Load

The results of the concentrated loads for specimens CK-Pl, P2, and PS are shown in table 9 and in figure 27.

Table ^.-Structural properties of non-load-bcaring

partition CK

[Weight, 5.33 Ib/W]

200

Concentrated load Impact load "

Specimen Miiximum

load Specimen

Maximum

height ot drop

PI

lb 191 183 197

//

ft 6.0

5.5

6.5 P2 72 } PS IS Average 190 Average-,. .._ . 6.0

" Span 7 ft 6 in. The concentrated loads were applied to one

face of each specimen on the gypsum wallboard

midway between studs and 1% to 2 ft from

one end of the specimen. Under the maximum

load the disk punched through the wallboard.

The properties of this construction under con- centrated load were not afl'ected by the fact

that there were four, not three, studs in the

specimen.

3. Impact Load

Impact test results for non-load-bearing partition specimens CK~I1, 12, and IS are shown

in table 9 and in figure 28. The impact load was applied to the center of one face of each specimen, the sandbag striking

the gypsum wallboard directly over the plywood ribbon and midway between studs.

To prevent misleading results due to local

effects on the loaded face of this type of specimen, the deflections and sets were measured

with two deflectometers and two set gages, not

one, as described in BMS2. The deflectometers were placed in contact with the unloaded

face of the specimen at midheight, one at each

inner stud; and the set gages rested on the

loaded face, one over each of these studs.

=8 leo

120

80

40

• • ^

o f o

/ o

/ —Mt—

4i

L

CK

0 CM 0,08 0,12

indenfaflon in. Figure 27.

Concentrated Load on non-load-bearing

partition CK.

Load-indentation (open circles) and load-set (solid circles) results for specimens CK-Pl, P2, and PS.

4

1^

1^

-5:

2

0

—O-

—-v^

• —

—

<

)

• p

—o- 7

» CD

1•

1• i

•— /

CK

0 12 3

olef/ecfion in,

Figure 28.

Impact load on non-load-bearing partition

CK.

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

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

[21]
The effects of the impact load are given in table fO.

Table 10.

Effects of impact load on non-load-hearing

partition CK

Description of effects

Face not loaded: Gypsum wallboard

cracked transversely near midspan Wallboard ruptured

transversely

B'ace loaded: AVallboard cracked

where sandbag struck^ Wallboard ruptured

where sandbac struck, Wallboard ruptured 1

ft from one end of the specimen

Studs: One or more studs

either split or ruptured at the dado

All the studs ruptured„. Specimen came into contact with the floor. Maximum height of drop

Specimen II

Height

of drop

2. 5

3.0

3.0

4.0

3.0

5.0

6.0

Deflec- tion

Specimen 12

1,65

2. 17

2.17

2. 17

Height

of drop

Deflec- tion

3.0

4.0

3.0

5.0

5.5

Specimen IS

Height

3.0

3.5

5.0

5.5

3.5

5.5

IB. 1.84

4. 35

2.00

Because there were too many studs in these

specimens, the maximum heights of drop were

greater and the deflections and sets were less than those of representative specimens.

VIII. FLOOR CL

1. Sponsor's Statement

Floor CL was a wood frame with plywood

subflooring, sheathing paper, and finish floor- ing on the upper face. The lower face was

unfinished, and the specimens were not painted.

The price of this construction in Washington, D. C, as of July 1937, was $0.313/ftl

(a) Description oj Specimens

The floor specimens shown in figure 29 were

12 ft 7M in. long, 4 ft 0 in. wide, and S^Ke in. thick. Each was a wood frame to which the

upper face was fastened. The frame consisted

of three joists. A, two headers, B, and bridging,

C. The upper face was plywood subflooring,

D, sheathing paper, E, and flooring, F.

Joists.—The joists, A, were Douglas fir, \%

by 7K in-, 12 ft 4 in. long, spaced 1 ft 4 in. on

centers. The ends of each joist were fastened

to the headers by two 20d common nails

through the header into the joist (not toenailed).

Headers.—The headers, B, were Douglas fir, 1% by 1% in., 4 ft 0 in. long.

Bridging.—The bridging, C, was Douglas fir, iKe by 2% in., 1 ft 3)2 in. long. Two bridging

pieces were placed crosswise betv/een the top

and bottom edges of adjacent joists at midlength and were fastened to the joists by two

8d common nails, toenailed through each end

into the joists.

Subflooring.—The subflooring, D, was four

pieces of five-ply Douglas fir plywood, in. thick. Two pieces were 1 ft 11% in. by 4 ft 1){ in. and two were 1 ft 11% in. by 8 ft 0 in. The grain of the outer plies was longitudinal.

There was a longitudinal joint along the center

joist, with !'4-in. clearance, and a transverse

joint on each side of the center joist, one joint

being 4 ft IVi in. from one end of the specimen

and the other being 4 ft 7^ in. from the other

end. The subflooring was fastened to the joists

and headers by 8d common nails spaced 6 in., and the nails in the two lines along the center

joist were staggered.

Sheathing paper. —The sheathing paper, E,

consisted of two sheets of rosin paper 3 ft 0 in. wide, laid lengthwise over the sheathing with a

2 ft 0 in. longitudinal lap. It was fastened to the subflooring at each end of the specimen by

12 staples.

Flooring.—The flooring was red oak, by

2% in., blind-fastened to each joist by one 8d

cut flooring nail through each strip of flooring.

The last flooring strip at one end was also fas- tened by three 8d cut flooring nails driven

through the face of the strip into the header.

(6) Comments

Floor sections are made in widths which are multiples of 1 ft 4 in. Lengths are equal to the

distance from the outer sill to the center girder.

The ends of the floor joists rest on a 2- by 6-in. wood sill and on a ledger strip on the center

girder. The joists are toenailed to the sill and

girder with two 16d nails at each end. A 2- by

8-in. header is fastened to the outer ends of the joists by two 16d nails at each joist.

The edge of the plywood subflooring of one

section overlaps half of the upper surface of the

edge joist of the adjacent section. The sec- tions are joined by 8d nails through the edge of

[22]
Figure 29.

Floor specimen CL.

A, joists; B, header; C, bridging; D, siibflooring; E, shoathiug |)aper F, flooring.

the overlapping subflooring;, spaced 6 in. Any

conventional type of finish flooring may be applied to the plywood subfloor.

2. Transverse Load

Floor specimen CL-Tl under transverse load

is shown in figure 30. The results for floor specimens GL-Tl, T2, and T3 are given in table

11 and in figure 31. Table 11.

Sinictural properties of floor CL

[Weight, 7.10 lb/ft2J

Transverse load » Concentrated load Impact load »

Specimen

Maxi- mum

load Specimen

Maxi- mum

load Specimen

Maxi- mum

height

of drop

Tl

Iblft 2 4fi9 558 320

PI

lb

b 1, 000

b 1, noo

b 1, 000

11

ft

b 10.0

b 10. 0

b 10.0 T2 a

T3 PS IS Average 449 Average- - _ b 1,000 Average--.. b 10.

0

» Span 12 ft 0 in.

b Test discontinued. Specimen did not fail. The speed of the movable head of the testing

machine under no load was adjusted to 0.17

in./min.

Under loads of 350 and 267 Ib/ft^ on speci- mens T2 and T3, respectively, one outer joist

split at a knot near midspan. Under the

maximum load two or three joists in each

specimen either ruptured or split between the

loading rollers.

3. Concentrated Load

The concentrated-load test results for floor specimens CL~P1, P2, and PS are shown in

table 11 and in figure 32. The concentrated loads were applied to the

upper face between joists over an end-matched

joint in the finish flooring 3 to 4X> ft from one

end. The sets after a load of 1,000 lb had

been applied to specimens Pi, P2, and PS were

0.015, 0.036, and 0.027 in., respectively, and

no other eft'ects were observed.

4. Impact Load

Floor specimen CL-Il during the impact test

is shown in figure 33. The results for floor specimens CL-Il, 12, and IS are presented in table 11 and in figure 34. The impact loads were applied to the center

of the upper face, the sandbag striking the

finish flooring over the center joist. After a drop of 10 ft the set in specimen // was 0.051

in., in 12 was 0.078 in., and in IS was 0.100 in. No other eft'ect was observed.

IX. ADDITIONAL COMMENTS

BY SPONSOR

In structures built of "American Houses"

prefabricated sections, the horizontal dimensions are based on multiples of 1 ft 4 in. A

section of a typical liouse is shown in figure 35. Foundations are of various types of conveii-

[23]
Figure 30.

Floor specimen CL-Tl under transverse load.

tional masonry construction. Wood sills, 2 by

6 in., are placed on the foundation walls,

leveled by means of sliims, and secured by

anchor bolts, ji by 8 in., spaced about 8 ft 0 in. The center girder consists of three 2- by 12-in. planks fastened together by 16d nails

and supported by the foundation walls and

by one column. The upper surface of the

girder is leveled to the top of the sills. The type of framing is similar to the con- ventional platform or western type of woodframe construction. Floor sections are placed

first, followed by the load-bearing partition

and wall sections. The ceiling joists, 2 by
Figure 33.—Floor specimen CL-Il daring Ike impact test.

[25]
8 in., spaced 1 ft 4 in. on centers, are then

placed on the top plates of the wall and partition sections, to each of which they are toe- nailed with two 16d nails. A second plate, 2 by 4 in., is applied to the top plate of the

load-bearing partition sections. This plate is dadoed halfway to space and secure the ceiling

joists, the bottom edges of which are dadoed to correspond. Ceiling finish is the same as that

applied to walls and partitions.

Rafter plates, 2 by 4 in., are fastened to each

ceiling joist by two 16d nails. Headers, 2 by 8

in., are attached to the end of each ceiling

joist by two 16d nails. Roof sections consist

of rafters, 2 by 6 in., spaced 1 ft 4 in. on centers,

and plywood sheathing. The sections are assembled in pairs, starting at one end of the

house, the ridge rafter (2 by 8 in.) being placed

at the same time. The sections are joined by

6d nails passing through the overlapping edges

of the sheathing into the rafters, spaced 6 in. The end of each rafter is fastened to the rafter plates by four lOd nails and to the ridge rafter

by two lOd nails. Any conventional roofing

material, such as shingles, may be applied to

tlic plywood sheathing. Gable end sections are

similar in construction to the walls, and the

ceiling joists and rafters are fastened to the

studs of the end sections by two 16d nails at each stud.

In a two-story house, the floor sections for the

second story rest upon the top plates of the first- story wall and partition sections. The bridging is applied to the floor and ceiling joists after the sections are in place.

The description and drawings of the speci- mens were prepared by E. J. Schell, G. W. Shaw,

and T. J. Hanley, of the Bureau's Building

Practice and Specifications Section, under the

supervision of V. B. Phelan. That section also cooperated in the preparation of the report.

The experimental data were obtained 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, H. Dollar,

M. Dubin, A. H. Easton, A. S. Endler, C. D.

Johnson, A. B. Lanham, A. J. Sussman, and

L. R. Sweetman.

Washington, October 24, 1939.

o

[26 J
BUILDING MATERIALS AND STRUCTURES REPORTS

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D. C, will place your name on a special mailing list to receive notices of new reports in this

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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^ BMS2 Methods of Determining the Structural Properties of Low-Cost House Constructions 10^ BMS3 Suitability of Fiber Insulating Lath as a Plaster Base lOjt BMS4 Accelerated Aging of Fiber Building Boards 10^ BMS5 Structural Properties of Six Masonry Wall Constructions 15^ BMS6 Survey of Roofing Materials in the Southeastern States 15^ BMS7 Water Permeability of Masonry Walls 10^ BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel 10(i BMS9 Structural Properties of the Insulated Steel Construction Company's "Frameless-Steel" Constructions for Walls, Partitions, Floors, and Roofs IQ^

BMSIO Structural Properties of One of the "Keystone Beam Steel Floor" Constructions Sponsored by the H. H. Robertson Co 10^ BMSll Structural Properties of the Curren Fabrihome Corporation's "Fabrihome" Constructions for Walls and Partitions 10^ BMS12 Structural Properties of "Steelox" Constructions for Walls, Partitions, Floors, and Roofs

Sponsored by Steel Buildings, Inc 15^ BMS13 Properties of Some Fiber Building Boards of Current Manufacture 10^ BMS14 Indentation and Recovery of Low-Cost Floor Coverings lOji BMS15 Structural Properties of "Wheeling Long-Span Steel Floor" Construction Sponsored by

the Wheehng Corrugating Co lOfS BMSI6 Structural Properties of a "Tilecrete" Floor Construction Sponsored by Tilecrete Floors, Inc 10^ BMS17 Sound Insulation of Wall and Floor Constructions 10^ BMS18 Structural Properties of "Pre-Fab" Constructions for Walls, Partitions, and Floors Sponsored by the Harnischfeger Corporation 10^ BMS19 Preparation and Revision of Building Codes 15^5 BMS20 Structural Properties of "Twachtman" Constructions for Walls and Floors Sponsored by

Connecticut Pre-Cast Buildings Corporation 10j5 BMS21 Structural Properties of a Concrete-Block Cavity-Wall Construction Sponsored by the National Concrete Masonry Association lOfi BMS22 Structural Properties of "Dun-Ti-Stone" Wall Construction Sponsored by the W. E. Dunn Manufacturing Co 10(J BMS23 Structural Properties of a Brick Cavity-Wall Construction Sponsored by the Brick

Manufacturers Association of New York, Inc 10^ BMS24 Structural Properties of a Reinforced-Brick Wall Construction and a Brick-Tile CavityWall Construction Sponsored by the Structural Clay Products Institute 10^ BMS25 Structural Properties of Conventional Wood-Frame Constructions for Walls, Partitions,

Floors, and Roofs 15^ BMS26 Structural Properties of "Nelson Pre-Cast Concrete Foundation" Wall Construction

Sponsored by the Nelson Cement Stone Co., Inc 10^ BMS27 Structural Properties of "Bender Steel Home" Wall Construction Sponsored by The

Bender Body Co lOi BMS28 Backflow Prevention in Over-Rim Water Supplies 10^ BMS29 Survey of Roofing Materials in the Northeastern States 10^ BMS30 Structural Properties of a Wood-Frame Wall Construction Sponsored by the Douglas

Fir Plywood Association 100 BMS31 Structural Properties of "Insulite" Wall and "Insulite" Partition Constructions Sponsored by The Insulite Co 150 BMS32 Structural Properties of Two Brick-Concrete-Block Wall Constructions and a Concrete- Block Wall Construction Sponsored by the National Concrete Masonry Association _ 100 BMS33 Plastic Calking Materials 100 BMS34 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 1 100 BMS35 Stability of Sheathing Papers as Determined by Accelerated Aging 100

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

[Continued from cover page III]

BMS36 Structural Properties of Wood-Frame Wall, Partition, Floor, and Roof Constructions

With "Red Stripe" Lath Sponsored by The Weston Paper & Manufacturing Co__ 10^ BMS37 Structural Properties of "Palisade Homes" Constructions for Walls, Partitions, and

Floors Sponsored by Palisade Homes 10^ BMS38 Structural Properties of Two "Dunstone" Wall Constructions Sponsored by the W. E. Dunn Manufacturing Co 10j5 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 10^ 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 100 BMS46 Structural Properties of "Scot-Bilt" Prefabricated Sheet-Steel Constructions for Walls,

Floors, and Roofs Sponsored by The Globe-Wernicke Co 10(S BMS47 Structural Properties of Prefabricated Wood-Frame Constructions for Walls, Partitions,

and Floors Sponsored by American Houses, Inc 100