National buieau oi ommdi

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

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

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

CENTRAL HOUSING COMMITTEE

ON RESEARCH, DESIGN, AND CONSTRUCTION

A. C. Shire, Chairman.

United States Housing Authority.

Howard P. Vermilya, Vice Chairman.

Federal Housing Administration.

Sterling R. March, Secretary.

Mary F. Taylor, Assistant Secretary.

Pierre Blouke,

Federal Home Loan Bank Board.

Hugh L. Dryden,

National Bureau of Standards.

Louis A. Simon,

Public Buildings Administration.

Luther M. Leisenring,

Construction Division (War).

Edward A. Poynton,

Office of Indian Affairs.

John F. Donovan,

Farm Security Administration.

George W. Trayer,

Forest Service (F. P. Laboratory).

RoLLo H. Britten.

Public Health Service.

George E. Knox,

Yards and Docks (Navy).

William R. Talbott,

Veterans' Administration.

Wallace Ashby,

Bureau of Agricultural Chemistry and Engineering.

NATIONAL BUREAU OF STANDARDS

STAFF COMMITTEE ON ADMINISTRATION AND COORDINATION

Hugh L. Dryden, Chairman.

Mechanics and Sound.

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

Clay and 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 Forest Service is cooperating with both

committees on investigations of wood constructions.

[For list of BMS publications and directions for purchasing, see cover page m]
UNITED STATES

N AT I O N A L

DEPARTMENT OF COMMERCE • Jesse H. Jones, Secretary

BUREAU OF STANDARDS • Lyman J. Briggs, Director

BUILDING MATERIALS

and STRUCTURES

REPORT BMS71

Fire Tests of Wood- and Metal-Framed Partitions

by

S. H. INGBERG and NOLAN D. MITCHELL

ISSUED MAY 12, 194 1

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

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

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • I94I

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

Partition constructions of materials and types that restrict the spread of fire contribute appreciably to fire safety. In buildings that are structurally of the fire-resistive or fireproof type, a fire thus can be prevented from spreading beyond the area in which

it originated, and in non-fire-resistive buildings its progress can be greatly retarded.

This paper gives the results of fire tests of partition constructions representative of a wide range in materials and design. The results are given in terms of performance under

recognized testing procedure. This enables regulatory bodies to require given ratings

for partitions in certain general locations, with assurance that practical constructions

are available that will meet the requirements. It also gives the builder a choice of constructions that will meet the requirements, thus making possible the use of the most

advantageous type in a given building or project, which should assist in obtaining the

desired degree of fire resistance at lowest cost. Partitions of given fire-resistance ratings are generally required as separations between tenants, subdivision of large areas, and for segregating hazardous occupancies,

processes, or storage. Even within an area for which no legal requirements for fire subdivision apply, the use of partitions of materials that will contribute a minimum to the severity of the fire and in some degree present a barrier to its spread is an effective means of structural fire control.

Lyman J. Briggs, Director.

[n]
Fire Tests of Wood- and Metal-Framed Partitions

by s. H. INGBERG and nolan d. Mitchell

CONTENTS

Page

Foreword ii L Introduction and scope 2 IL Materials 2

1. Lumber 2

2. Channels 1 2

3. Lath 2

4. Sand 3

5. Plaster . 3

III. Construction of partitions 4

1. Framework 4

(a) Wood frames 4

(b) Steel frames 5

2. Lathing 6

3. Facings 7

(a) Board facings 7

(b) Gypsum plaster 8

(c) Lime plaster 8

(d) Portland cement plaster 9

(e) Equivalent volume proportions 10

(f) Curing of plaster 10

(g) Thickness of plaster facings 10

4. Mineral fills 10

IV. Equipment and method of testing 11

1. Equipment 11

2. Method of testing 13

V. Results of tests 13

1. Partitions of plasterless types 13

2. Plastered partitions with combustible

framework and combustible lath 16

3. Plastered partitions with wood framing

and incombustible or partly combustible lath 18

(a) Gypsum lath 18

(b) Paper-backed metal fabrics 18

(c) Metal lath, gypsum plaster 19

(d) Metal lath, lime plaster 24

(e) Metal lath, portland cement

plaster 25

4. Hollow partitions with incombustible

framing and incombustible or partly combustible lath 25

V. Results of tests—Continued. Page

5. Solid plaster partitions with incombustible framework and incombustible or partly combustible lath 28

(a) Board plaster bases . 28

(b) Metal-lath base, gypsum plaster 28

(c) Metal-lath base, portland ce- ment plaster 34

6. Partition facings as protective finish over combustible framing 35

7. Deflection and stability 36

VI. Summary and discussion 38

1. Board partitions without plaster 39

2. Hollow wood-framed partitions with

plaster on combustible bases 40

3. Hollow wood-framed partitions with

plaster on incombustible or partly

combustible bases 42

(a) Variations in results due to thickness 42

(b) Partitions with gypsum plaster bases 43

(c) Wood-stud, metal-lath parti- tions 43

(1) Gypsum plaster 43

(2) Lime plaster 44

(3) Portland cement plaster 44

4. Hollow steel-stud partitions 44

5. Solid plaster partitions 44

6. Partition facings as protection for combustible supports 45

7. Resistance to the hose stream 45

8. Significance of fire-endurance limits__ 46

VII. Appendix A. Standard specifications for

fire tests of building construction and

materials, American Standard ASA No. A2-1934 47

VIII. Appendix B. Selected references on fire tests of wood- and metal-framed parti- tions 51

[1]
ABSTRACT

This report describes in some detail the test partitions

and gives the results of 147 fire-endurance or fire and

hose-stream tests conducted at the National Bureau

of Standards. Seventy-eight of the partitions were

of wood or framed with wood studs and faced with

wood, wood fiber, or gypsum boards, or with plasters

applied on wood, gypsum, expanded-metal, or wire

laths. The others were of hollow or solid incombustible

noabearing types, most of which were framed with

steel channels and had body or facings of gypsum or Portland cement plaster on metal laths. Most of the wood-stud partitions were of the load-bearing type,

and 38 of them were tested under a constant working

load while exposed to fire. Their fire-resistance limits, depending on the facings, ranged from 10 min with

M-iu. wood-fiber insulating boards applied on each

side to 2 hr with 1-in. -thick facings of neat woodfibered gypsum plaster. Filling the spaces between

studs with mineral wool increased the fire resistance appreciably. The fire-resistance limit was considered reached when (a) failure under load or passage of flame

occurred, (b) the limiting temperature rise (250 degrees

F average or 325 degrees F maximum) was reached on

the unexposed side, or (c) cotton waste in contact therewith became ignited. The protection given the wood studs by the fire-exposed facing, as based on the

limiting temperature rise on the edges facing the fur- nace, ranged from one-sixth to one-third of the fire- resistance limit of the partition construction as such. The results with metal-framed hollow partitions dif- fered little from those with wood-stud partitions having

the same facings, insofar as the rise of temperature on

the unexposed surface was concerned, but the former

remained longer as barriers tc the spread of fire after such technical end points had been reached. For the

solid plaster partitions, 2 to 2}^ in. thick, the range in fire resistance was from 20 min with portland cement sanded

jilaster or mortar to 2}^ hr with unsanded fibered gypsum

plaster. Sanded gypsum plasters gave intermediate results. For incombustible materials not subject to decided

cracking or spalling when exposed to the furnace test, it was foimd that the fire resistance, as limited by the temperature rise on the side not exposed to fire, varied approximately with the 1.7 power of the thickness of solid partitions or combined thickness of facings for those of hollow type. This is in fair agreement with

relations derived from the theory of heat conduction.

I. INTRODUCTION AND SCOPE

In this series of tests the fire resistance of the

usual types of framed partitions was determined. Of the 147 partitions tested, 76 were framed with wood studs and 63 with steel studs,

44 of the latter being of the solid type. There

were included four solid concrete partitions,

two wood partitions, and two of precast gypsum,

which were without framing.

Most of the partitions were 16 ft long and

10 or 11 ft high (fig. 1). Two of them were 8

ft high, and one was 9 ft high. Eight partitions were 4 ft wide and 4 ft high (fig. 2). Twenty of the 16-ft-long partitions were divided into 2 sections, A and B, each 8 ft long (fig. 3) and 2 into

3 sections, A, B, and C, each 5% ft long (fig. 4). All of the wood-stud partitions, except two

with the studs set flatwise would be considered

as of the load-bearing type. Thirty-eight of these were tested under a constant working

load while exposed to fire. The steel-stud

partitions, as well as the partitions of other

types not tested under load, were tested re- strained within the heavy movable frames into

which they were built. Descriptions of the partitions and the principal results of the tests are given in tables 1 to 6, inclusive.

II. MATERIALS

1. LUMBEK

The frameworlv of the wood-stud partitions was made of yellow pine or Douglas fir scantlings of 2- by 4-in. nommal size No. 1 Common

or the Structural grade. The baseboards applied to most of the partitions were of 1- by

8-in. yellow pine. Some of the partitions had

wood picture molds. The plywood and framing

lumber of the prefrabricated plywood wall were

of Douglas fir clear of knots. The plywood was

three ply and bonded with phenol resin glue.

2. Channels

Most of the steel frames for the partitions were made of either cold-rolled strip-steel or

hot-rolled channels, usually of %-in. depth.

Strip-steel channels of 3 /4-in. and 6-in. depths

used in a few tests had a triangular perforations

through the webs to lessen their weight and

aft'ord openings for the passage of wires and

pipes within the wall. The steel channel studs

in the prefrabricated insulated wall B19 were formed from No. 18 gage strip steel. The webs

of these channels had three rows of parallel

slits to interrupt heat flow. The facings were

of No. 18 gage leveled steel sheets.

3. Lath

The majority of the partitions were con- structed with lath obtained from the stocks of

[2]
locnl de:i.loi-s in building materials. A low luid new types of lath supplied by the inauuliicturers. The laths for the difi'erent partilious are indicated in tables 2 to 5, inclusive. The

weights of the expanded-metal lath ranged

from 2.2 to 3.5 Ib/yd.^ and for stiffened

expanded-metal lath from 3.25 to 3.5 lb/yd ^ Plain wire lath for one test (No. 95) was woven of No. 21 gage wire with 2% meshes per

inch, galvnnized after weaving, and weighed

4. Sand

Potomac River l)uil(liiig sjiiid was used for iill sanded plasters except for the three partitions

which were constructed \\ith jilaster ui which

Fox River (IlUnois) snnd was nsed. The

Potomac River sand consisted largely of quartz

(about 95 percent), the remainder being mica,

calcite, pyroxenes, and feldspars. In the dry

condition it weighed 100 Ib/ft^ The Fox

River sand consisted of about 60 percent of

Figure 1.Sixteen- by ten-foot purtition, paitly witlulfuu-ii J rum furnace, after fuc-enduraucc ted.

2.1 lb/yd ^. Paper-backed expanded-metal and

wire laths were also included.

Gypsum lath and plasterboard were % in. thick and were either plain, perforated, or indented, as indicated in table 3. Most of tl:e wood lath was of spruce, but some

puie and cypress laths were nsed. They were

/4 to % in. thick by 1% to 1% in. wide.

quartz, 30 percent of calcite and dolomite, and the

remainder of weathered pja'oxenes and feldspars.

It weighed 110 Ib/ft^ in the dry condition.

5. Plaster

The plaster, for the most part, was obtained

from stocks of local dealers in builduig materials.

Before using a given lot of gypsum plaster, a

[3]
sample was usually tested for conformity with

Federal and American Society for Testing

Materials specifications for gypsum plaster,

except for chemical analysis. For most lots,

the time of set in neat mortar was also determined. Plaster requiring more than 24-hr to set, for the neat mortar, was usually rejected as not

suitable on account of drying conditions in the

test laboratory. For the last 33 tests with

gypsum plasters this limit was fixed at 20 hr.

taken from a representative number of batches

and tested at 30 or 60 days. The results are given in tables 2 to 5. These cubes were stored

in air in locations adjacent to the partitions.

III. CONSTRUCTION OF PARTITIONS

1. Framework

(a) Wood frames

All wood frames, except for plywood wall Bl7, were made of 2- by 4-in. scantlings of Douglas

Figure 2.Four-foot-sqiiare partition -panel placed ready for fire-endurance test; test X5.

Lime and portlai'.d cements were also tested

for conformity with the requirements of Federal

specifications, except for chemical analysis.

Bagged hydrated lime was supplied for most of the partitions . Generally, high-magnesia lime was

used as an admixture in portland cement plasters or for white finish and high-calcium lime for most

of the scratch and brown-coat lime mortars.

Two-inch-cube samples of the plaster as pre- pared for the construction of the partitions were

fir 01- southern pme, the material for only a few

of the latter being of the long-leaf species. The

plates were of single pieces 2 by 4 in. or, in some instances, the bottom plate was made of

two such members. The 2- by 4-in. studs were

spaced 16 in. on centers, and most of them had

wood blocking at midheiglit fitted to form fire stops in the spaces between studs. Two of the

partitions listed in table 1, Nos. 101 and 102, were constructed with marginal frames only.

[4]
(b) Steel frames

The steel frames of the most of the partitions were made of hot- or cold-rolled channels as

vertical members, engaging the top and bottom

plates or runner channels attached to the panel

frames. They were assembled by wiring the

members together with two or more ties of

doubled No. 18 gage galvanized wire.

The frames of hollow partitions 18, 19, 23, 24,

26, and 30 (fig. 5) were made of single channels

which had triangular openmgs punched in the

webs to leave diagonal lattice members joining

the angle flanges. These studs were attached

to the top and bottom runner channels by wiring

to extension clips on each end. Framing made

of two rows of %-in. channels in most cases had

sheet-metal spacer clips attached to opposite

channels at one-fourth, one-half, and threefourths the height of the partition, and was held

in alinement at midheight by a runner channel

wired to one row of channels on the inside. Two frames for hollow partitions 122 and 126

had iK-in. channels between the %-in. vertical

channels at the one-third points to serve botli as spacers and stays which held the frame in alinement during the plastering operations.

For test 25 only one stay at the midheight was

attached (fig. 6). The studs for nearly all solid partitions having

metal lath were made of /4-in. or 1-in. channels,

5

spliced with a short bent piece on the upper end

to form a slip joint to provide for expansion.

Runner channels or 2- by 4-ui. scantlings were

wired at midheight or one-third points on studs

for solid partitions and removed after the scratch coat had set. The solid partitions of spraj'ed-ou

Portland cement mortar had no studs but were

reinforced with 4-in.-square mesh of No. 6 gage

wires welded at intersections.

The channel studs in the prefabricated panels

of Bl9 were spot-welded to the face plates.

Figure 3.

Partition divided into two acctionf;, each 8 ft long; test 131.

[5]
The six panels comprising the wall were united

with continuous channel plates at the top and

bottom, fastened with self-tapping screws.

Self-tapping screws were also used to fasten the

face plates of one panel to the edges of the

stud of the adjacent panel at vertical joints.

2. Lathing

The wood lath was fastened with 3d or 4d

nails to each bearing. End joints were staggypsum lath held in place by nails fitted with

expanded-metal pads Iji by 1% in. folded around

the heads, six for each 16- by 48-in. board.

The 1-in. -thick boards made of excelsior

compressed and cemented together (Nos. 45,

46, 140, and 141, table 4) were held in place by

inserting the lateral edges between the flanges

of the H -shaped sheet-metal studs (fig. 7). Tiers were started alternately with pieces of

different lengths to avoid having horizontal

Figure 4.Partition divided into three sections, each 3 ft 4 long: test 103.

gered every seventh course. Fiberboard was

nailed at intervals of 4 to 6 in. with 3d or 4d

nails, except that for %-in.-tliick boards 5d

nails were used. Nailing was done first on

intermediate bearings and lastly at the edges.

Gypsum lath and plasterboard were, for the

most part, nailed with 4d plasterboard nails

spaced about 4 or 5 in. on centers. End joints were staggered from course to course and for most of the partitions the courses were spaced

]{ in. apart. One partition (No. 115) had

joints at the same level on opposite sides of

studs. The asbestos-board lath, made of layers

of corrugated or indented asbestos paper (partitions 47, 49, and 50, table 4) was similarly

held in place. Sheet-metal clips were placed in the horizontal joints midway between studs to keep the otherwise free edges of the boards in

alinement.

Expanded-metal lath and wire lath were

nailed to wood studs in nearly all instances

with 6d nails spaced not over 7 in. on centers

[6]
on each bearing and were driven to a depth of

about 1 in. and bent over. The edges of the

lath were lapped and tied with No. 18 gage

galvanized wire between studs.

The expanded-metal lath was tied to steel

3. Facings

(a) Board Facings

The combustible facings (table 1) comprised

fiberboards, two untreated (Nos. 60 and 128j

Figure .5.Stn p-sttd channel studs with perjo rated web; plaster removed after test; test £4-

studs at intervals of 6 to 8 in. with No. 18 gage

galvanized wire, and the lapped edges were tied

together between studs. The end laps were

staggered from course to course. The laps were made with the upper edge of the course

outside the one above.

301518°—41 2

and one of flameproofed materials (No. 61);

Douglas fir plywood (No. Bl7); tongue-andgrooved ceiling boards ^Ks hi. thick (Nos. 102

and 103); and pine mill flooring 1% in. thick

(No. 101). Some of the partitions of this group

(Nos. 60, 61, 90, 101, 102, 103, 127, and 128)
were painted as described in table 1 . The %-in. and K-in. gypsum boards (tests 90, 127, 131,

and 135) were incombustible except for the

paper facings. The hollow gypsum units in

partitions 7 and 8 were tongued and grooved on the edges and had smooth exposed faces. Partition Bl9 had facings of metal sheets.

(6) Gypsum. Plaster

The mixtures of gypsum plasters were made

coat was applied over the scratch coat before

set had begun, thus more effectively imiting the

two coats. A 1- or 2-day interval was allowed between

the applications of scratch and brown coats on

metal lath. The partitions were usually rea- sonably dry on the surfaces before the white

finish was applied. Six partitions (Nos. 31, 32,

33, 34, 49, and 50, table 4) had wood sawdust

incorporated with the gypsum plaster, the last

Figure 6.Double ji-in. channel studs with channel runner spacers at top, bottom, and iitidheight; plaster removed

after test; test 25.

on the basis of weight of dry materials. The

gypsum cement plaster weighed approximately

67 Ib/ft^ and dry sand 100 Ib/ftl The plaster was sisal-fiberod unless otherwise noted. Woodfibered plaster contained approximately 1 per- cent by weight of fiberized wood. Additions of

wood and asbestos fiber were made as noted for some tests. On rigid plaster bases the brown

two having also 2 percent of asbestos fiber added.

The plaster on 11 partitions (Nos. 1, 2, 105, 106,

107, 116, 117, 118, 119, 122B, and 126A) had

additions of wood fiber, and 1 (No. 126B) both

wood fiber and asbestos.

(c) Lime Plaster

Three partitions (Nos. 43, 44, 134, and 142,

[8]
table 2) were made with facings of lime plastei- on wood lath. The scratch and brown coats were allowed to dry on the surface before suc- ceeding coats were applied. The weight of the

dry hydrate on which the mixture ratios are based, was assumed to be 40 Ib/ft^. Lime plaster applied on metai lath (Nos. 42,

100, and 108, table 3) was allowed to dry on

the surface before succeeding coats were applied.

Seven test partitions (Nos. 40, 41, 51, 52, 99,

table 3) also had small quantities of short-filx-r asbestos. Portland cement phisters were characterized by greater hai-(hiess than other i)]asters

but were somewhat more (Hnicult to apply.

Small quantities of asbestos in portland cement

plaster r(>sulted in better workability. A 94-lb

bag of Portland cement was assumed to be 1 ft''. Scratch coats of portland cement plaster fibercid with asbestos were applied to the metal plaster

bases of partitions 95, table 3; 98, table 4; and

Figure 7.Shcci-incial-stud framing and plaster base of 1-in. -thick boards made of com pressed excelsior bound with magnesium oxysidfate cement: test 4-5.

136, and 137) had Keene's cement incorporated

in the lime plaster to improve its strength.

One partition (No. 109) had a small proportion

of Portland cement incorporated for the same

purpose. Dry Keene's cement weighed 67

Ib/ftl

(d) Portland Cement Plaster

Portland cement plasters had admixtures of

hydrated lime and three (Nos. 87, 88, and 95,

113, table 5, to receive brown coats of sanded

gypsum plaster.

Four solid partitions were made of mixtures

of portland cement and aggregates, with water

for dampening, sprayed with compressed air against backmgs of plywood. The plywood was removed after the cement had set hard.

The aggregates were sand (Nos. 124 and 138,

table 4), sand and asbestos (No. 125), or sand

and wood sawdust in equal volumes (No. 139).

[9]
(e) Equivalent Volume Proportions

While proportions by weight are given for lime and portland cement plasters in the tables,

in general it was sought to obtam for them 1:1, 1:2, 1:2K, 1:3, and 1:4 proportions by volume

of dry cementing materials and dry sand. Dry

sand was found to weigh from 98 to 110 Ib/ft^

However, in. proportioning the mixes, all materials were weighed, using the weight equivalents

for the different materials.

( /) Curing of Plaster

A period of not less than -1 weeks was allowed

for the curmg of plaster before testing.

Attempts were made to adjust curmg conditions for the type of plaster and prevailmg

temperatiu-e and humidity conditions. For

gypsum plaster the limit on the required time

of set previously indicated was intended to compensate to some extent for the drier conditions to be expected in the test room as compared with those in a building being plastered.

Further, burlap hmig over the sides of some of the panels was kept damp for periods ranging

from 2 days to 1 week. The lime plasters, and

lime and Keene's cement plasters, were dampened between coats when considered necessary. While it is appreciated that for some of the

partitions the curmg conditions may not have

been as favorable as job conditions, and that

this may be reflected in the fire-test results, it

is believed that the resulting properties of the

plaster come within the limits considered acceptable in building practice.

The Portland cement and portland cementlime plasters were cured either under the conditions of the test room with little or no dampening (Nos. Xl, X2, and 37, table 5) or were

covered with burlap and dampened or sprayed

two or three times each day for 1 week (Nos.

84 to 8G, table 3). While the difference is shown in the strength of the plaster, the fire resistance does not appear to be greatly in- fluenced, since the stronger plaster is more

likely to crack and spall mider fire exposur(\

During the last 2 or 3 weeks before testing

all plasters were cured dry, the drying being

accelerated when considered necessary with a ludt heater and fan or with low heat from the

furnace with the panel m place. This drying

was essential in order that most of the free, or uncombined, water might be driven off'. The

temperature and humidity conditions during

this period were such that no loss of combined

water in gypsum or portland cement plaster

would be expected.

ig) Thickness of Plaster Facings

The thickness of plaster facings given in the

tables are to be taken as the average over the

face of wood, fiberboard, gypsum, and asbestos

laths, and as the average from the back of ex- panded-metal and wire laths. The thicknesses

in some cases were based on the thickness of grounds or grounds and lath, others on measure- ments after test, and a few on measurements

made before test. The thicknesses based on measurements after test are in general less than

the actual thickness before test on account of shrinkage of the facing during test, which for neat gypsum plaster is of the order of 5 to 10

percent. This slxrinkage decreased with in- crease of sand in the mixture. Those based on

thickness of grounds are probably also less than

the actual thickness due to the tendency of the

plasterer to overrmi the grounds, particularly

where white-coat finish was applied. The

variation in thickness over the same partition was indicated to be greater than the above dif- ferences and accounted in part for the local high

temperatures on the unexposed side that limited

the (ire resistance of most of the partitions.

Variations of this extent and even greater

sliould be expected in building construction.

4. Mineral Fills

Twelve of the paiiitions had the spaces

between the wood studs filled with mineral wool.

One (No. 44) had the fill placed pneumatically,

another (No. 103B) had loose bulk mineral wool

placed by hand packing as the board facbigs were applied, and the other nine had fills composed of mineral wool in bat form, most of which had waterproofed-paper backing. The

weiglits of these fills ranged from 0.6 lb to 1.5 lb/ft for bats (2.4 to 5.1 lb/ft and for pneumatic and hand-packed fills 2.0 and 2.9 lb/ft

(6.5 and 9.6 lb/ft The weight for the bats

is given in terms of their 16-in. nominal width.

As placed between studs of 2-in. nominal thick- ness spaced 15 to 16 in. apart, their average

[10]
SECTION LONGITUDINAL SECTION HALF ELEVATION

0 I ^ 3 't 3 IP J5 ' SCALE

Figure 8. —Wall-testing furnace.

A, furnace chamber; B, burners; (

', thermocouple protection tubes; D, pit for debris; E, mica windows; F, air inlets; G, flue outlets and dampers; fJ, fire-brick furnace lining; I, reinforced concrete furnace shell; K, gas cocks; L, control valve; M, ladders and platforms to upper observation windows; N, movable fireproofed test frame; 0, loading beam; P, hydraulic jacks; Q, test wall: R, asbestos pads covering thermocouples on unexposed surface

of wall. weight per unit of stud space area would be

greater by 10 to 15 percent.

The prefabricated metal wall, Bl9, had an

insulating fill of expanded vermiculite weighing

6.0 lb/ft.3

IV. EQUIPMENT AND METHOD OF

TESTING

1. Equipment

Most of the tests were made witli a furnace

accommodating walls 16 ft long by 8 to 11 ft

[11]
high (fig. 8). Thirty-eight tests of wood-stud

partitions were made while they were suhjected

to load by means of hydraulic jacks, P, set in the lower part of the test frame, A', to force a beam, 0, against the bottom of the partition,

Q. The total load for a 16-ft-wide partition was about 30,500 lb, corresponding to 360 Ib/in.^ of net area of wood studs. The other i)artitions were tested in protected steel frames capable

inlets, F, at the bottom of the furnace supplied

additional air, the flow being accelerated when

necessary with jets of compressed air. Nine thermocouples of Clu-omel-Alumel whes,

C, strung on porcelain insulators and protected

in %-in. standard black wrought-pipe mountings,

capped at the furnace end, were distributed

through the furnace chamber, A. Their indications were read with potentiometers. Measm-eFiGURE 9.

Rear wall of furnace.

of restraining them against vertical or longitudinal expansion.

The large furna,ce was heated by 92 gas

burners, B, controlled by one large valve, L, for

all and a %-in. stopcoclv for each (fig. 9). One

horizontal line of burners was controlled with a

single lever operating a cross bar, K, loosely

bolted on the stopcock handles. The burners were of the induction type with venturi mixing

tubes, part of the air for combustion being

drawn in around the gas jet. Six 4-in. pipe

ments were made at 5-min intervals during the

first horn' and at 10-min intervals thereafter

for controlling temperatures in conformity witb

the standard reference curve insofar as practicable. The temperatures within the partition

and on the unexposed surface were also obtained

with Chromel-Alumel thermocouples, those on

the surface being of No. 22 or No. 24 gage wires

coiled under 6- by 6-in. soft asbestos pads

{R, fig. 8) about )lo-in. thiclv. In some of the

earlier tests, both thermocouples and mercury-

[12]
in-glass thermometers were used for the latter purpose.

Deflections of the partitions were determined

at nine points by measuring to the surface from

vertical wires stretched opposite the center line

of the partition and 4 ft each side of the center

line.Hose-stream tests were made on 33 partitions

by projecting the stream from a [}i-m. Underwriters' pattern fire-hose nozzle supplied with

water at 30-lb pressure througii a 2}^-m. rubberlined fire hose. The pressure was measured at the base of the nozzle with a gage connected

through a %-in. nipple perpendiculai' to the

dhection of flow. The small panels were tested in a gas-fired

furnace (fig. 2), the temperatures of which were

indicated by thermocouples at six points in the

chamber. Temperature indications within the

partition and on the unexposed surface were

obtained at three or more locations.

2. Method of Testing

The tests, for the most part, were conducted

in accordance with the Standard Specifications

for Fire Tests of Building Construction and

Materials of the American Standards Association, No. A2-1934 (Appendix A, page 47). The

principal deviations from the specifications were

in the size of the 8 small panels and the division

of 19 of the large partitions into 2 sections and

2 of them into 3 sections having areas less than

the prescribed minimums. However, due to the similarity of the sec tions and the absence of restraint at borders between sections, it is thought that conditions obtained substantially

equivalent to those for the undivided panels.

It will also be noted that most of the constructions tested in 4- by 4-ft panels were also tested

in panels of larger size. Nearty all of the loadbearing partitions subjected to the hose-stream

test were tested in the restrained condition without load, instead of being tested under load, as provided by the test specifications, the ability to sustain working load for the full rated period

having been proved in previous fire-endurance

tests. Each partition with its test frame was placed

to form one wall of the combustion chamber of the furnace. The loads were applied to those

to be tc^sted under load ])ic\ ions to stiirtiiig llir fire and maintained until failure occun-vd. in

several tests the fires were continued beyond

the time when the first criterion of failure had

been observed, in order to determine the subsequent behavior of the partition. If a partition began to fail under load, the load was

reduced to prevent collapse. The condition of the fire-exposed surface could be observed during the test through mica windows, E.

At the end of the fire-exposure period of the

fire and hose-stream tests, the frame containing

the partition was withdrawn from the furnace

and the hose stream promptly applied to the

hot surface, the tip of the nozzle being approximately 20 ft away. The period of application

of the hose stream was IK niin per 100 ft^ of area of the partition for ratings of less than

2 hr, and 2^ mui per 100 ft^ for ratings of 2 to 4 hr. The criteria of failure of walls, partitions,

and incombustible facings over combustible

members are listed in paragraphs 13 (a), 13 (d), 15 (a), 15 (d), 24 (a), and 24 (c) of the standard

fire test specification (Appendix A, page 49).

The criteria of failure in the fire and hose-stream

tests are given in paragraphs 13 (b), 15 (b), and 24 (b) of the same specification.

V. RESULTS OF TESTS

The principal characteristics of the partitions

and the results of the tests are given in tables

1 to 5, inclusive. The text outlines the more

important results and otherwise supplements

the tabular data. Many of the details of the

performance not considered of particular importance have been omitted.

1. Partitions of Plasterless Types

Wood-stud partitions faced with K-in. -thick

untreated fiberboard (tests 128 and 60, table 1) failed at 9K and 16K min, respectively, material

in the facings of the former weighing about

16 \h/it^ and in the latter 26 lb/ft^ thus indicating better performance for the denser material

from the standpoint of fire resistance. With

flameproofed fiberboard (test 61), other\\-ise

comparable with the untreated fiberboard of

test 60, failure occurred at 29K min. Similar

partitions faced with %-m. and )2-m. gypsum

[13]
wallboards (tests 90 and 127) failed at 24^ min

and 4lK min, respectively. Figure 10 gives curves of temperatures of the furnace and on

the surface and inside of the partition. Filling

the spaces between the studs with 3-in. (full thick) glass-wool bats weighing 0.6 Ib/ft^, and

rock-slag wool bats of similar thickness weighing 1.2 Ib/ft^ (test 131) increased the time to

failure of the same type of partition with %-m.-

thick gypsum wallboard facings to 51 K min

with bats not secured and to 57K min with the

the 1-hr rating as far as I'esistance to the hose

stream is concerned.

The untreated wood fiberboard facings

flamed freely throughout the tests. The flameproofed board flamed freely for the first 5 min,

flaming decreasing thereafter, so that after 10

min little active flaming was noted. The paper

facings on the gypsum boards exposed to the

fire flamed only for 1 or 2 min.

The wall of plywood panels (No. Bl7) having

mineral-wool bats weighing 2 Ib/ft^ failed by

TIME IN HOURS

Figure 10. -Temperatures in tests of wood-stud partitions faced with gypsum wallboards, Nos. 90 and 127, and wood

fiberhoards, No. 128.

bats secured with Sd finish nails driven through

the bats and into both sides of studs about

12 in. apart vertically. These end points were due to failure to support the full applied load.

The test was continued beyond this point, and

the limits of the construction as a nonbearing

partition were obtained at 6 IK min for the

portion with the fill not secured and at 66 min

for that secured with nails. A view of the

unexposed side after test is shown in figure 3. In test 135 the filled construction qualified for

temperature rise of 325 degrees F (181 degrees

C) at one point on the unexposed surface at

52)2 min. Glow was observed on the surface

not exposed to fire at 54^2 min and spread to form a hole 9 in. long by 4 in. wide at 60 min.

The plywood on this side did not flame. That

on the flre-exposed side did not flame as freely as the other wood facings after the first 7 min of

fire exposure.

Test 101 showed the vulnerability of untreated

tongue-and-grooved 2- by 6-in. planidng when

[14]
C3 O

£•8

C 3 „

o «

«1H= 2;

ran 3 !2 II g

0

£ ~ £ g B -r; m

£ o ,o > S£ o.-a « . o g

y] /.

r-l W .-H r-. CD

a 0

. <0

; ^

; C ;.S 3

(33

O.D.

^

W

p.a0

p, 5

3^3

c

c;o£

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'-psum studs.gypsum

)d_,

studs.

, o

c ° 7 B: •r &

•3 a

O 3 is

6li'3— o

>, a

S 3 g

cd o o —

2 3 3 £ & m

CM

i

VI

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;.0:

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lot

-D

Ei23 3 "

GJ_3 ^^^^ ||

ft^ is I

1

i

a

C8 _^

Eh I?

3015is°^l 3 [15]
set vertically to form a solid partition. The

application of two coats of whitewash to both

sides of one-half the area of this partition (No.

10 IB) gave less than 1 -minute increase in fire resistance. Flame and hot gases were trans- mitted through the joints between planks due

to slu-inkage from fire exposure. Tongue-andgrooved core pieces of less width covered with

three ply or heavier cross banding on each side

would give more favorable results for the same

thickness.'- An increase of 80 percent in the fire resistance was indicated in test ] 02 as the result of placing

a membrane of asbestos paper weighhig 30

lb/100 ft- between the two layers of %-in.-thiclv tongue-and-grooved fir ceiling boards set vertically with joints staggered. A somewhat

greater increase with the asbestos paper was

indicated in the test of the hollow partition 103

(fig. 4) having a single layer of ceiling boards on

each face, a part of which, No. 103C, had asbestos paper between the studs and the ceiling

boards on both sides. Mineral-wool fill between

the studs of this type of partition. No. 103B,

also gave some increase in fire resistance. Had

the fill been secured in place between the studs, a greater fire resistance would have resulted, as indicated by the condition of the areas in which

the mineral wool remained in place.

The small nonbearing partitions of precast

hollow imits of gypsmn, Nos. 7 and 8, failed by

rise of temperature of 325 degrees F (181 degrees

C) at one point on each after periods of fire exposure of 78 and 84 min, respectively. The

only metal wall, No. Bl9, also made up of prefabricated miits, was tested as a nonbearing

construction. The limiting temperature rise of 250 degrees F (139 degrees C) as the average of nine locations on the unexposed surface in this

test was reached at 28 min.

2. Plastered Partitions With Combustible

Frameavork and Combustible Lath

The fire resistance of partitions with gypsum

plaster over wood lath having the hollow spaces

filled with mineral wool (test 129, table 2) was

' Clement R. Brown, Fire tests of treated and untreated wood partitions,

J. Research NBS 30, 217 (1938) RP1076.

indicated to be about twice that of the unfilled

partition (test M). The latter gave results approximately the same as that of one with an

equal thickness of gypsum plaster over )^-in.- thick combustible fiberboard (tests M, N, 58,

and 59, table 2). The flameproofed board used

as lath gave lowei' I'esults than the untreated

board, the plaster falling oft' the flameproofed

board earlier in the test because of bond failure

(tests 58 and 59). Also, results of exploratory

fire tests with seven 4- by 4-ft panels, not given

in the tables, led to the conclusion that no significant gain in fire resistance could be expected

from the use of wood laths which had been

flameproofed. With flameproofed fiberboard

of %-in. thickness as the plaster base (test 53),

the fire resistance was about 100 percent greater

than with a comparable base ji in. thick. Lime plaster over wood lath gave a little lower

fire resistance than gypsum plaster on the same

base (tests M and 43). With lime plaster on wood lath and spaces between studs filled with

mineral wool (tests 44, 134, and 142), the fire resistance was greater than that of the unfilled partitions if the plaster was fairly dry at the

time of testing.

In test 44 the fill was blown into place after the facings had dried, and in test 142 a longer

seasoning period than usual and drying in front of the warm furnace were resorted to in an eft'ort to drive off the excess water in facings

applied after the fill was placed. However,

partition 134, for which the facings were also applied after placing the fill in the form of bats, was aged for the usual period. Failure under

load occurred at 28/2 min, or 3% min earlier than for unfilled partition 43, the moisture in the facings inducing early and general spalling

of the plaster probably contributing to the

early failure. Appreciably better results than

with lime plaster were obtained with the limeKeene's cement mixture in partition 136, which was also filled with mineral-wool bats. On

account of poor functioning of the loading

equipment, the full working load could not be

applied up to the end of the test, but the

indications are that it would have been sus- tained for at least 1 hr.

[16]
r ? 5- C ^ l_ C

2*

o S £ c S c

fe 5£ b 2 o 5

•c Si2

^2. 6

5 I

I

+CO

E

CO QO

-s9Jdirioo

OOc; O

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00

9 3 E J 9'a V

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!M CM ^ ^ CO

»0 »C »0 113 O 00

1 H o c

' 03 P o

o § £

^1

ss9n3ioiqx

CO rc ^ ^ CO CO

[17]
3. Plastered Partitions With Wood Framing AND Incombustible or Partly Combustible Lath

(a) Gypsum Lath

The plasterboard lath (tests E and F, table 3) were 30 by 32 in., that for test E having an

intermediate paper layer. These tests were made in 1923, when this type of board was in

use. Nearly all plaster fell off the fire-exposed

partitions is a little over 1 hour. Gypsum lath

indented to give additional bond with the

plaster (tests 54 and 55) or indented and per- forated with holes smaller than % in. (tests 64,

65, 76, and 77) did not give increased fire re- sistance, probably in part because of the poor

quality of the plaster used, as indicated by the

low strength. The results obtained in tests 96

and 120 may also be due to tliis cause. The

tests did not indicate any definite difference in

Figure 11.

Wood-stud 'partition faced with gypsum plaster on perforated gypsum lath after fire and hose-stream test 17

side early in both tests. Tests 1, 2, 13, and 14 were made 7 years later, and the greater fire resistance may be due to differences in both the

plaster base and the plasters. Perforating the

plaster base with %-in. or %-in. holes having

aggregate area of 2% percent or more of the

base, resulted generaUy in increased fire resist- ance (tests 16, 17, 96, 89, 120, and 123, fig. 11).

Wlule variations in results are apparent, probably due in large part to the properties of the

plaster, the average fire endurance for these

results for the lath placed edge to edge from

that spaced % to /$ in. apart.

{b) Paper-Backed Metal Fabrics

In point of fire resistance of the plastered constructions, there were no significant differences

among the tlu-ee types of paper-backed metal

fabrics, assuming the same average thiclmess of

plaster. These comprised (1) wire fabric made

of No. 14 or 16 gage galvanized wires welded at

intersections to form 2-in. square mesh and

[18]
backed with a heavy paper held by No. 16 gage

wires spaced 4 in. on centers and welded at 4-in. intervals through holes in the paper backing, for

tests 93A, 94A, and 104A; (2) No. 22 gage

expanded metal with l%- by 2Mf,-in. fUamond

mesh with a backing composed of two sheets of kraft paper cemented together with asphalt and

attached to the metal with strips of asphalt

cement, for tests 93B, 94B, and 104B; and (3) a welded fabric made of No. 16 gage wires 1}^ in. on centers, inserted through corrugated paper

plaster was in three thicknesses, those given in

the table beuig the average thickness of plaster,

allowing for the corrugations in the plaster base. The plaster for the %-m. thickness was finished even with %-\n. grounds applied to the edges of

the studs. The results for the different sections

are consistent with the respective thicknesses of

plaster.

(c) Metal Lath, Gypsum Plaster

Wood-stud partitions faced with gypsum

2

O

mO

a

r»i m

0)o

m

z

H

O

>

PI

FIRE ENDURANCE TEST

lit 2 TIME IN HOURS

2)4 HOSE STREAM TEST Figure 12. -Temperatures in fire-endurance and fire and hose-stream tests of wood-stud partitions faced with woodfibered gypsum plaster on expanded-metal lath; tests 118 and 119.

and welded to V-crimped stiffening ribs spaced

4-in. on centers, for tests 97A to C. Partitions

with facings of 1 : 2 and 1 : 3 sanded gypsum plaster on the first two laths, and % in. thick as measured from the face of the wood studs,

failed just short of 1 hour but met the requirements for 1-hour rating in resistance to the hosestream test. The fire resistance was improved

by the use of 1:2 plaster for both the scratch

and the brown coats (tests 104A and 104B).

On the last of these three laths (test 97) the

plaster on exj^anded-metal lath, sanded 1:2 for the scratch coat and either 1:2 or 1:3 for the

brown coat, gave about 1-hr protection with

%-in. thickness of plaster, but two partitions

with 1:3 brown coat (Nos. 22 and 110) and one

with 1:2 brown coat (No. 143) failed in the

hose-stream test to qualify for the 1-hr ratmg

according to present test specification. Such

failure also was obtained in test 144 with 1:3

brown coat and total plaster thickness of /s in. Further information on the resistance to hose

[19]
Table 3.

Plastered partitions with 2- by Jj--in. wood

fTlie plaster mix for all tests was proportioned by weight of dry plaster to dry sandl

Test No.ThickDess

13

14 115

17

123

78

120

65

64

66

76

77

93A

93B 94A

94B

104A

104B 97A

97B

97C

143

20

21

74

22

110 144

Sketches

In.

5H

5H

51/2 5M

5K'

51/2

51/-2

5!.2

51/2

51/2

^PLAS TEIS s 1

i WOOD STUDS

Same design asE

_do_

.do_

_do.

.do. do.

I iPtRFORATED 6yP6UM LATH /PLASTER

WOOD STUDS

.Same design as 16

do

-do.

-do.

.dodo.

51/2

51^

514

514 5H

5H

5H

6H

6H

654

6!4 5K

514 5H

6!4

-do.

-do.

I PAPER BACKED LATHSI

"T

Same design as 93A.

.-..do

--..do __.

...dodo

WOOD STUDS

Plaster

Kind of lath

Plasterboard.

...do Gypsum lath.

---do

.. do.

--.do. ..do.

Perforated gypsum

-do.

.do.

do.

-do....

.do..-.

.do....

Indented gypsum _

Kind

Gypsum

-

.do. Wood-fibered gypsum.

....do

Indented and iiorfor- ated gypsum.

-.--do

.do.

.do.

---.do.

I , /EXPANDED METAL LATH/PLASTER

l/^OOD STUDS

Same design as L.

--.-dodo

.do.

.do.

-do. _do_

Paper-backed wire-

/Paper-baeked expandl ed metal. Same as 93A Same as 93B _ Same as 93A Same as 93B

.

/Metal backed with

\ corrugated paper.

Expanded metal.

.do-

.do.

.do-

.do. .do.

-do.

.do-.

Gypsum.

.--.do....

----do....

-do.

-do.

.do.

-dodo,

.do-

-do.

-do.,

...do.

-.-do.

- .do.

.do.

-do.

.do.

.do.

-do.

.do-

.do-

.do.

.do.

.do.

.do.

.do.

.do.

.do. -do-

.do.

.do..

Scratch

coat

1:2

1:2 Neat

Neat

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2 1:2

1:2

20
framing and incombustible or partly combustible lath

[The plaster mix for all tests was proportioned by weielit of dry plaster to dry sand]

Plaster—continued

Test No.

Finish Average

thickness

E White

F do v>

1 __do

2 ....do

13 i do H

14 do

115 ...do

16 (Jo Vi

17 ...do

123 ...do M

89 ...do Vi

96 ...do !,<->

78 _._.do

120 do

54 Float

55 _ . do

64 do Vi

65 do

76 White

77 do

93A . ...do H

93B ...do Vi 94A do I'M 6 94B ...do

1(HA do Yi

104B do H

97A

97B do \ t

97C

L Float %

143 . .do ?4

20 ... do H

21 do 'Me

74 do H

22 do Yi 110 do H

144 do %

Compressive strength

Ik.lin:'

Tests

Failure Kind of test -

350

1,080

1.080

680 680

830

1, 410

1,530

1, 320

780

1,220

750

470

420

820

1. 020

1,230

930

630

930

630 930

630

930

630

620

500

620

500

400

1230 850

(Tensile, neat 205) ...do..

....do

Firo and load...

.do

.. do

Fire endurance

Fire and load...

-do.

-do.

470

180

960

260

870

500

Fire and hose -

Fire and load. ...do

... do ...do ...do

....do

Fire endurancr

Fire and load

Fire and hose. .

Fire and load.

.

...do

j-Fire and load .

} ...do

j-Fire and hose.

.

}....do

j-Firo and load. .

}..._do

Fire endurance.

do

jFire and hose.

.

jFire and load.

.

do.

jFire endurance.

Fire and hose .

.

} do

jFire and hose..

Kind Time

mm

Glow 30

...do 42 fLoad . .. 55

\ Flame through 56)-:) fLoad 62

\ Flame through.. 63 fLoad 50)-i ITemp max ... 54 Temp max . .

.

571.3 ILoad.. - - 66 ITemp max 72

fLoad . 90 \Temp. max 89

No failure. . . .

.

iLoad 62 [Temp max 70 ILoad .. .. .. - 591 . fTemp max 65 fLoad 45

I Temp max 51^4

48 ITemp max 61 fLoad 50K> ITemp max. .

.

58

fLoad fTemp max..

(Temp max. \Temp avg__ fLoad

l.Temp max. No failure.. fLoad ITemp max.. fLoad ITemp max..

fLoad iTemp max..

fTemp max.

fLoad No failure...

-do /Load fTemp maxfLoad \Temp max.. (Temp avg_. dodo

Xo failure..

Hole through., /Load \Temp max

/Load \Temp max Temp max

Hole through. do

Hole through..

Notes

4150H

47}4

49)-> 41

51

45

56

531-: 60

58

58!-;

621, 71

65!: 7322

35

52

60+

Plasterboard 30 x 32 x ?^ in. Studs sec flatwise.

Do.

j Laths 16 X 48 x in. spaced \i to % in. apart,

j Do. jNo space between laths. Do.

/Six nails with metal-lath pa<is around heads to each

1 16 X 48 in. lath.

fEach lath had 48 holes, -li-in. diam. (2.75% of area).

1 No space between laths.

Each lath had 48 holes, 34-in. diam. (2.75% of area). No space between laths. 30-min fire exposure.

^48 holes iMc-in. diam. (3.7%). (Laths with 54 holes Ji-in. diam. (4.2%). Laths M in1 apart. /Laths with 48 holes ?4-in. diam. (2.75%). Laths !4 in.

f apart. (Laths with 54 holes ?i-in. diam. (2.2%). Laths 14 in.

i apart. iLaths with 42 holes iMe-in. diam. (2.8%).

/Each lath had 300 indentations in. deep. (7.3%).

\ No space between laths.

Do. /Each lath had 95 indentations (2.3%) and 35 holes Me-in.

\ diam. (1.1%). Each lath had 95 indentations (2.3%) and 35 holes ?-i6-in. diam. (1.1%). 30-min. fire exposure. /Each lath had 108 indentations (2.6%) and 42 holes 1 Vi e-in.

1 diam. (2%). Laths !4 in. apart. (Each lath had 100 indentations (2.4%o) and 46 holes

1 Mifi-in. diam. (2.2%). Laths !4 in. apart.

-2 X 2 in. mesh by No. 14 gage wire.

>l!s X 2Yi6 in. mesh No. 22 gage metal. 30-min Are exposure. Do. Same as No. 93A except plaster mix and No. 16 gage wire

in mesh. Same as No. 93B except plaster mix. }Each ! 3 length of the partition was plastered to give thick- ness as measured from the face of the paper.

Fire was stopped after 60 min.

30-min fire exposure.

(Piaster ?i6 in. thick at point of failure by temperature

f rise.

30-rain fire exposure. Do. Do.

[21]
Table 3.

Plastered partitions with 2- by4-in. wood framing

Thickness

5!4

51/1 Mi

5%

5y>

5H

514

514

514 5H

5Vi 5?4

SVi

514 5K5H

51/4

51,

Sketches

/ WIR£ LATH /PLASTER

tVOOD STUDS

/EXPANDED METAL LATH /PLASTER

Same design as i:)OA ...do WOOD STUDS

.do.

.do.

-do. .do

.do. 'METAL LATM /PLASTER

T

Same design as 42.

....do ...do

WOOD STUDS

.do.

.do. .do.

.do.

.do.

.do

.do

...do.

...do.

..do

...do.

do.

.do.

Kind of lath

Wire lath.

Kxpaaded metal.

.do.

.do.

.do.

.do.

.do. .do. .do.

..do.

.do.

do.

do.

do.

-do. do-

-do-

.do-

-do-. do.

.do-,

-do-

-do-

-do.

-do-

.do.

Plaster

Kind

Portland and gypsum

.

Gypsum.

.do. do. Wood-fibered gypsum.

dodo

do -.. do

LimeLime and Keene's

cement. do

do ----

do.

-do- -do.

-do- Limsdo. Lime and Portland cement.

Portland cement .

.

.do.

-do-

-do-

-do-

-doScratch

coat

1:2

1:1 1:2 Neat

Neat

Neat

Neat

Neat

1:4

1.8:1:10.5 2:1:6.6

2:1:12

1. 1:1:8.7

3:1:13. 5

1:3. 5 2:1:8

1:2. 2

1:2

1:2

*1:2. 3

1:2.

1

1:2. 1

'Calcareous sand.

[22]
and incombustible or partly combustible lath—Continued

Test No.

Plaster—continued

Finish

95 Float

130A do.

130B do

132 do_ 107A do_ 107B tio_ 118 do

119A 119B . ..do

42 do40 do.

41 do

51 White

52 do. 137A _Q0- 137B do.

99 Float

100 do.

108 White

109 do.

75 Float

84 do.

85 do.

86 ...do

87 do88 doAverage

thickness

'Me

Compres

sive strength

2710

210

680

1210 810

1660

1600 1600

1400

1530

85

330

330

320 420

320

330

3, 620

2. 130

4, 030

3,300

3. 750

3, 320

5, 320

5. 600 2,690

2, 250

2, 720

2, 160

Tests

Kind of test

Fire . Load.

Plose.

Firo and load

.

.do

Fire and hose.

Fire endurance.

.

do

Fire and hose. .

.

Fire endurance

...do

Fire and load

.do.

Fire endurance.

I Fire and load..

l....do

Fire endurance.

....do _...do

Fire and loaci _

....do

Fire endurance.

Fire and load .

.

jFire endurance.

IFire endurance. (Hose test •Fire endurance.

Fire and load.

.

do

Failure

Kind

Temp max. No failure .

.

do

fLoad \Tcmp maxLoad No failure. Temp max.

do No failure.. Temi) max.

do

fTemj) max.

1 Load

/Temp avg.

1 Load Temp max. fTemp max.

I Load /Temp max.

ILoad Temp avg . du Temp max.

[Load

I Temp max- /Temp max.

I Load Temp max. fTemp max.

/Load Temp max. Temp max.. No failure... Temp max.

. ..do fTemp max.

iLoad..

Time

mm.

61

100

102J/2 108^2 128H

128

30

501/2

45

62

351/2 4714

6043M

45

95

87

491/i 50

51

H

54

581.4 401-2

431/2 63 H mi

34

50

67 14

6287H

Notes

,Scratch coat of Portland cement and sand with 10 lbs of hydrated lime and 3 Ih of iisbestos per bag of cement. Brown coat of gypsum jjlaster. 64-min fire exi)osure.

Jspaces bctwe<'ri studs filled with mineral-wool bats.

Do.

Spaces between studs filled with mineral-wool bats. 45- min lire exposure. Tested as nonbearing. Do.

Tested as nonbearing. 60-min fire exposure.

T'ested as nonbearing. Do.

Spaces between studs filled with mineral-wool bats. Do. Lime in plaster partly carbonated by burning coke (Lime in plaster partly carbonated by burning coke.

i Hose stream applied after 60-min fire exposure. Broke

I hole through jLime in ])laster partly carbonated by burning coke. Do.

10 lb of hydrated lime per bag of cement added to Portland cement plaster. Do.

10 lb of hydrated lime per bag of cement added to Portland

. cement plaster. 40-min fire exposure.

'10 lb (if 1 1,N il 1:1 1 nl lime per bag of cement added to Portland

. cenicnl pl;i>ic'i'. 6 lb of asbesl.o;; per bag of cement added. Due to equip- ment trouble, only K load was applied and sustained

for 76 min. 3 lb of asbestos per bag of cement added.

[23 J 301618°—41 4
streams of partitions with gypsum -plaster fac- ings was obtained with steel-stud partitions

(table 4)

.

Filling the stud space with mineral-wool bats

(tests 130 and 132) increased the fire resistance

to Iji hi with the 1 :2 proportion for the plaster.

There was apparently little gain from increasing the richness of the mix to 1 : 1 where mineralwool fill was used.

It was observed that gypsum plasters having

slow set, as tested neat, were usually less satis- factory in the fire tests than those havmg faster

set. An exception is noted for those plasters

which apparently had their time of set adjusted

by the addition of an accelerator to the retarded

plaster, which were indicated to give no better

results than the jjlasters having slow set. One partition (No. 95) with lath of woven

wire had a scratch coat of portland cement

piaster gaged with lime and 3 lb of short-fiber

asbestos per bag of cement, and a brown coat

0 1:3 gypsum plaster floated to give %-in. thickness over the studs. The end point of the fire-endurance test, as determined by rise of temperature of 325 degrees F (181 degrees C)

at one thermocouple location on the unexposed

surface, was reached at 61 min, after which the

hose-stream test was applied with the result

that, although much of the lath and plaster was thrown down from the fire-exposed side, no hole was broken through the partition.

Two fire-endurance tests (Nos. 107 and 119)

and one fii'e and hose-stream test (No. 118)

established a fire-resistance rating of 2 hr,

combustible, for nonbearing wood-stud partitions faced with 1 in. of neat wood-fibered

gypsum plaster on expanded -metal lath (fig. 12)

and correspondingly less for thinner facings.

{(1) Mi tal Lath, Lime Plaster

Partition 42, table 3, faced with lime plaster on metal lath, failed owing to temperature rise on the unexposed side at 36 min. The incorporation of about Yi part of Keene's cement to

1 part of lime by weight (tests 40, 41, 51, ;md

52) increased the fire resistance to an average

near % hr. The leaner mixes appeared to give

fully as good results as those with less sand.

A similar partition (No. 137, A&B) having a

fill of mineral-wool bats weighing 1 .35 Ib/ft^ withstood a fire-endurance test for about 1% hr. No

fire and hose- stream test was made to qualify

it for a fire-resistance rating.

Four tests of partitions with lime plaster

partly carbonated by gas from burning coke

(Nos. 99, 100, and 108) gave residts somewhat

higher than with the uncarbonated plaster,

although the increase was not very decided.

Less cracking and spalling of plaster occurred.

Due to its dry condition, the limiting temperature rise occurred sooner than if the plaster

had been seasoned at room conditions for the

usual period. The early temperature end point

obtained with cement-lime plaster in test 109

may have been partly due to the same condition, although in this case more plaster fell during the early part of the test. In the carbonating of these plaster facings,

two panels were placed side by side with the

space between them closed to form a chamber

into which the flue gas from the stoves was

discharged, the indicated carbon dioxide concentration in the chamber being generally in the range 2 to 6 percent, with occasional concentrations up to 12 percent. The treatment was applied for 5 to 8 hours and was repeated

in some cases on 2 or 3 successive days for both

scratch and brown coats. The depth to which

any liardening of the plaster occurred varied

from Vii to }i in. While carbonation of the

iime was apparently not at all complete, either

frt)m the standpoint of the depth aft'ected or the degree thereof within this depth, it proba.bly represented the extent to which carbonation would take place in 100 or more years

untler ordinaiy conditions in buildings.

A 3- by 3-ft wood-stud panel faced with

%-m. thickness of lime plaster on metal lath, of a mix comparable with that used in test 42, was almost fully carbonated by piping carbon

dioxide gas into the stud spaces. The plaster

became very hard and had a compressive

strength in excess of 2,000 Ib/in^. As subjected to fire exposure corresponding to the

standard furnace test, no cracking or other

disruptive effects were noted, the limit of per- missible temperature rise on the unexposed

side being reached at 1 hr 4 min. The panel was too small to give fully conclusive results,

particularly as no load was applied during the

test.

[24]
(e) Metal Lath, Portland Cement Plaster

Tlie results with facings of portland comciit

plaster on metal latli did not difi'er greatly in point of temperature rise on the unexposed side

from those with lime, or lime and Keene's

cement plaster. While the plaster on the fire- exposed side cracked and in part fell ofl', that on the other side retained its integrity better,

and good resistance obtained in the hose-stream

test. The fire resistance was increased only

4. HoLi.ow Partitions With Jncomuuhtiulk

Framing and iNcoMuusTiiiLK or Partly

Comrustible Lath

Hollow pai'titions liaiiied on steel channels

and faced with a to '%6-iii. thickness of 1:2 sanded gypsum plaster on metal latti, tested as nonbearing constructions, gaA'c fire-resistance

ratings in excess of 1 houi- in lour out of five fire- endurance tests (Nos. 23, 38, 39, 25, and 35,

table 4) and in one fire and liose-stream test

TIME IN HOURS

Figure 13. —Temperatures in fire-endurance and fin and ho.^e-strcam tests of metal-stud partitions faced with sanded gypsum plaster on metal lath; tests 72, 73, and 111.

slightly (test 86) by the use of a sand contauiing

30 percent of calcite and dolomite histead of the

high-silica sand employed in most of the tests. A greater improvement was made by incorporating small quantities of short-fiber asbestos

in Portland cement plasters, as may be seen from

the results of tests 87 and 88. Only a mhior

amomit of crackhig and spalling occurred in these tests, which can be ascribed in large part

to the greater integrity of the fire-exposed

facings.

(No. 26) also met the requirements for the 1-hr ratmg. Partitions of the same construction

but with 1:3 sanded gypsum plaster for the

brown coat did not meet the requirements for 1-hr rating hi two of three fire-endurance tests (Nos. 18, 19, and 73) and in one of two fire and

hose-stream tests (Nos. 72 and 111). In test 73, the temperatiu'es ciu'ves of which are given

in figure 13, calcareous sand was used. In one

test. No. 98, with scratch coats of portland

cement plaster, the 1-hr fire resistance was

[25]
Table 4.

Hollow plaster partitions with incombustible framing

[Framing, H-in. hot- or cold-rolled channels for each face unless otherwise noted .

Thickness

43m

iH

41/i

41/2 m

m

5

54W

Sketches

J:5TJFFENED EXPANDED METAL LATH

PLASTER OPEN WEB CHANNEL 3TUD5

Same design as 18

I /EXPANDEO METAL LATH /PLASTER

DOUBLE CHANNEL STUDS

Same design as 72 do

do

T

STIFFENED EXPANDED METAL LATH

PLASTER OPEN WEB CHANNEL STUDS

Same design as 23_ ....dodo...

T DOUBLE CHANNEL STUDS

Same design as 38

.do-

.do.

.do.

.do.

.do-

.do-

-do.

do.

Kind of lath

[Stiffened expanded

\ metal.

.do.

Expanded metal.

.do.

.do.

.do.

(Stiffened expanded

\ metal.

.do. .do.

.do.

Expanded metal.

-do.

.do.

.do.

.do.

.do.

.do.

-do.

.do.

-do.

Plaster

Kind

Gypsum.

-do.

.do.

.do.

.do. /Portland cement and

1 gypsum.

•Gypsum.

.do.

.do. -do.

.do.

.do.

.do.

.do.

.do.

.do. Wood-fibered gypsum.

do

Wood-fibered gypsum,

plus 1H% of asbestos. Portland cement

Scratch

coat

1:2

1:2

1:2*

1:2

1:1. 5 1:2 1:2

1:

1

7:

6:1:

1:0.5 Neat

Neat

Neat

1:2.

1

'Calcareous sand.

[26]
and incombustible or partly combustible lath; nonbearing

The plaster mix for all tests was proportioned by weight of dry plaster to dry sand]

Test No.

72

111

73

26

35

31

33

122A

122B

126A

126B

83

Plaster—Continued

Finish

Float.,

_._.do

._..do

_.._do

..__do

_-..do

Float and

whitewash.

.do.--

.do_.-

.do__-

....do--

__..do._

Trowel..

__..do.-

.--.do-.

White...

do.-

Trowel-.

do-.

Float...

Average

thickness Compressive strength

H

H

'Ml H

IMe

1

1

390

410

880

410

1100 650

2660

300

800

1080

710

390

620

2060

2270

1040

910

3660 3260

Tests

Kind of test

Fire endurance _

..-.do

Fire and hose.

.

do

Fire endurance

....do Hose test

/Temp max. \Temp avg..

Fire enduranco.

do

Fire and hose. ....do

-do.

_do.

-do.

_do.

.do.

.do-

.do.

.do.

do.

}.-..do.

Failure

Kind Time

Temp max. Temp avg..

Hole through. -

No failure. fTemp max.. \Temp avg.. Temp avg-. No failure...

/Temp max. iTemp avg-

.

/Temp max.. ITemp avg -

.

No failure... /Temp max.. (Temp avg-.

Temp max. Temp avg__

/Temp

ITemp

/Temp

\Temp

/Temp

\Temp

/Temp

\Temp

/Temp

ITemp

ITemp

ITemp

/Temp

ITemp

/Temp

ITemp

/Temp

\Temp

max..

avg.- max..

avg._ max..

avg-_ maX-.

avg-- max..

avg_. max., avgmax.

avg.. max..

avg... max..

min

49

56

66H

69

601/2

6768

47

5465

76

6572

139 138H

166

168

1341/4 137^2 156 16438!^

41

Notes

jsM-in. open-weh channel studs.

Do.

Y4-\rx. channel studs, each stayed by three steel spacer

clips and one -K-in. channel horizontally at midheight. 30-min fire exposure.

Do. Framing same as No. 72. IScratch coat plaster of Portland cement and sand.

J min Are exposure.

>VA-m. open-web channel studs.

) Do.

3H-in. open-web channel studs. 30-min fire exposure.

i6-in. open-web steel channel studs.

|?4-in. channel studs with 6-in. spacers height from bottom.

Vi, Vi, and %

^>i-in. channel studs wired to steel channel spacing runners at bottom, midheight, and top. Framing same as No. 72. Mix, 7 plaster, 1 sawdust. Framing same as No. 72. Mix, 6 plaster, 1 sawdust, 6 sand. Framing same as No.

' 72. yi-'m. channel studs wired to IH-in. steel channel runners

' between at Ys and heights of partition.

\ Do.

\ Do.

}• Do.

^Framing same as No. 72.

[27]
developed, and at the end of the hour the i.iarti- tion successfuUy withstood the liose-stream test. There apparently was little difference in results ascribable to types of framing, such as integral channel studs (tests 18, 19, 23, 24, 26,

and 39) versus %-m. channels on each side

spaced and stayed with clips (tests 72, 111, 73,

98, 38, 35, 31, and 33) or with horizontal channel

runners (test 25). The total thickness of the

partition in the range to 7% in. also did not

affect the results appreciably. The same is true for increase in the richness of the plaster

mix from the 1:2 to the 1:1K proportion (compare tests 23, 25, 35, 38, and 39 with test 24).

The fire resistance obtained in tests of partitions faced with neat wood-fibered gypsum

plaster (Nos. 122B aiul 126) applied on metal

lath was approximately 50 percent greater than

that obtained with facings of 1:2 sanded gypsum plaster, allowing for the difl'erence in thickness. With a mix consisting of 7 parts

by weight of neat gypsum plaster to 1 part of sawdust (test 31) or 6 parts of neat plaster to 1 part of sawdust and 6 parts of sand by weight

(test 33), there was indicated little difference

in fire resistance for these hollow partitions from

what obtained with the same thickness of 1:2 sanded gypsimi plaster, tliat for the one being

higher and for the other lower by about the same mai-gin

.

Portland cement plaster (test 83) gave approximately the same results as simila.r facmgs

on wood studs (table 3).

5. Solid Plaster Partitions With Incombustible Framework and Incombustible OR Partly Combustible Lath

(a) Board Plaster Bases

The plaster base in tests 45, 46, 140, and 141

(table 5) consisted of a 1-in. -thick board made of excelsior bound with magnesium oxysulfate

cement (fig. 7). With a %-in. thickness of

1:2)^ sanded gypsum plaster on eacli side forming a solid partition 2]i in. thick, the end point

due to temi)erature rise was not attained before

the partition collapsed at 1 hx. 8 nun, but rather

wide openings between the channels forming

the studs occurred before the end of 1 hr. The companion partition (No. 46) successfully

passed the hose-stream test after a 30-min

fire exposure. In the construction of partitions

140 and 141, two No. 10 gage iron wires were

run horizontally along each face of the board 30

in. from top and bottom and wired to alternate

studs. The studs were wired to the runner

chaiuiels at the top and bottom. No objectionable cracks occurred at the panel joints in these tests, a fire resistance of over 1 hour

obtaming for the partition of 2%-in. average

thickness. This, as well as partition 141 made

with 1 : 1 sanded gypsum plaster, was of uneven

thickness, the limiting temperature rise for the

latter occurring at 47 min at a point where the

thicl>;ness was 2 in . A similarly constructed partition made with

a %-in. -thick board of corrugated asbestos

paper plastered with a %-m. thickness of 1:2

sanded gypsum plaster to make a solid partition

2 in. thick (test 47) failed at 48}2 min. Another

partition (No. 49), 2%f, in. thick, made with a somewhat harder asbestos-paper lath, having a core of Ke-in. -thick cement-asbestos board, and

covered with a plaster composed of 86 percent

of gypsum, 12 percent of sawdust, and 2 percent

of short-fiber asbestos, failed in the fire-endur- ance test at 2 hr, 13 min. A partition of the same construction (No. 50) but of 2-in. total thickness was subjected to the fire and hosestream test after a 30-min fire exposure. This

construction might withstand the hose stream

after a longer fire exposure and thus qualify for a higher fire-resistance rating than 1 hr.

(b) Metal-Lath Base, Gypsum Plaster

Curves showing typical test results with

sanded plaster are given in figure 14. Partitions

of 2-in. thickness with 1:2 plaster proportions

for the scratch coat and 1:2 or 1:3 proportions

for the brown coat gave approximately the same average results in fire-endurance tests 27,

66, X4, 29, 63, table 5. The same may be

said with respect to the average relative per- formance of 2)2-in. -thick partitions with the same proportions for the plaster (Nos. 28, 68,

X5, 30, aud 70). The results from 2%- and 2%-

in. -thick partitions of the same plaster compositions, Nos. X8, 56, and 114, lie between those

from the two groups above. The highest indi- vidual results obtained, however, for a partition

in each group havmg the 1:2 plaster for both

[281
coats, and indications are, that witii well-set plaster of good quality in this propoi'tion, the

1-hr fire-endurance limit can be attained lor partitions 2% in. tliick and, with wove assui- ance, in tlie 2}4-in.-tliickness with 1:2 seraleh coat and brown coat of either 1 :2 or 1 :3 ])laster.

In one of three fire and hos(>-streani tests the 2-in. solid partition of 1:2 gypsum plaster on metal lath met the requirements of this test for the fire-resistance rating, 1 hr (No. 91). In one test (No. 36) faihu-e occurred at a metal

the requii'emeuts after a fin^ e.xposiii'i' of 'M\ miu, thus establishing tlie 1-hr rating.

The use of a ijortlaiid cement plaster scratch coat in test 1 18 did not iill'ord the improvement

that was obtained in similar plaster constructions for two hollow partitions (Nos. 95 and

98, tables 3 and 4), the gypsum l)r(twn coats

falling ofl' in ])art from both the fire-ex]X)sed

and unexposed sides before the end of the test. Partitions 50, 02, arid 03 were applied on a welded wire lath having perforated cori'ugatedTIME IN HOURS

FiGUHE 14.—Temperatures in fire-endurance and fire and hose-stream tests of solid partitions of sanded gypsum, plaster on metal studs and metal lath; tests 68 and 69.

base bead near the top of the partition, in- tended to serve as a ground for a picture mold.

For the other partition failing in the hosestream test. No. 67, as also for one witli 1:3

brown coat mix (No. 112), the plaster was of relatively low strengtli. A 2]i-m. solid partition

of 1 :2 plaster throughout did not pass the liose- stream requirements after a 40-min fire exposure

(No. 69), but a partition of the same plaster and

thickness (No. 92) and one of the same thick- ness and of 1:2 and 1:3 plaster (No. 71) met

paper backing (fig. 15). The results were

comparable with those obtained for similar

plaster applied on expanded-metal lath. The use of neat wood-fibered plaster (tests

X7, 106, 116B and 121B) more than doubled

the fire endurance of 2-in. solid partitions over

that obtained with sanded gypsum plaster of

1:2 pi'oportions. The fire and hose-stream

test. No. 117, qualified 2-in. or thicker partitions

of neat wood-fibered gypsum plaster from this standpoint for any rating below 4 hr. The

[29]
Table 5.

Solid plaster partitions with incombustible

[Framing J4-in. hot-rolled or cold-rolled channels unless otherwise noted. The

Thickness Sketches

2

21/2

22M

21/2

2K> 2M

2'A

2

/METAL LATH

CHANNEL STUDS

Same design as X4_

do

-do_

.do_

-do.

-do.

.do.

.do.

.do.

- METAL LATH /PLASTER

CHA/^NEL STUDS THEPMAX BOARD /PLASTER

21/2

254

2

2Mr.

2

2

2

22%

21/2 2^6 2H

21/2

21.4 2H2H2%

2M

21.16

2)-i 2M6

222M6

2M6

T -^/Z SUPPORTS

Same design as 45 _ . I /ASBESTOLATH /PLASTER

CHANNEL STUDS

Same design as 66. do

do

do

do

.do.

-do. -do.

-do.

.do. -do.

-do.

.do.

.do. METAL LATH

CHANNEL STUDS

Same design as X7

do...

do..

-do. .do. do.

.do.

Kind of lath

Expanded metal.

.do.

-do.

.do.

-do.

-do. ---do Welded fabric-

-..-do

...do

Expanded metal.

fl-in. wood fiber mg

\ oxysulfate board.

do

N-in. asbestos lath

(.soft).

Expanded metal.

-do.

-do. -do.

.do.

.do.

.do.

.do.

.do.

.do.

.do.

-do.

.do.

.do.

.do.

.do.

.do.

.do.

.do.

-do. .do.

.do-

. doKind

Plaster

Scratch coat

Gypsum...

-do.

.do-

.do_ /Portland cement and

1 gypsum. Gypsum

-do.

.do.

-do.

-do.

.do.

...do

-do.

I ---do.

-do.

.do.

.do.

-do. -do.

-dodo.

-do.

-do.

.do. -do.

-do. .do.

.do.

.do.

Wood-fibered gypsum

--.--do...

do....

do.,-.

do-.-,

do-... Gypsum.

do....

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2

1:2. 5

1:2. h

1:2

1:2

1:2 1:2

1:2

1:2

1:2

1:2

1:2

1:2 1:1.5

1:0. 5 Neat

1:2.5

1:1

Neat

Neat

Neat Neat

Neat Neat

7:1

6:1:6

Brown coat

30
framing and incombustible or partly combustible lath; nonbearing

plaster mix for all tests was proportioned by weight of dry plaster to dry sand]

Test No.

X4

29

30

112

113

70

71

56

62

63

X5

66

67

91 114

28

92 X8

n21A

121B

140

141

X7

105

106 116A

116B

117

32

34

Plaster— Continued

Finish

Float.

Float and white wash, do

Float White

Float

--..do White

Compressive strength

-do.

-doFloat

-

White

-

.do-

-do.

Float.

Float and white wash- Trowel

Float White

do

Float and white wash..

Floatdo

dodo White

do-.- -.-

.do-

-do.

Float.

-do.

-do-

-dodo-

....do. White.

TrowelIb/in.'950

590

540

500

660

250

,700

240 670

330

630

250

866

230 930 420

950 650

820

810

660

600

590

540

500

390

510 890

740 650

540

500

620

840

680

660

2,013 2,280

1, 470

1,820

1,710

1,490

1, 490

1,580

865

620

Fire and hose.

.

1 Fire endurance. /Hose test

Tests

Kind of test

Fire endurance

...do-

--. doFire endurance... Fire and hose

Fire endurance. --

•Fire and hose

iFire endurancedo.

-.-do.

Fire and hose.

Fire endurance.

...dodo

Fire and hose. -

• do

--..do

•Fire endurance

.

• do

--..do

Fire and hose ...do

•Fire endurance. .. ---.do

-...do

.do- do.

Fire endurance

do-..- do

---.dodo

Fire and hose.

.

Fire endurance.

....do

Failure

Kind

'I'emp. avg.

/Temp, avg ITemp. max... /Temp. max... \Temp. avg Hole through

.

Ignited waste. Hole through

-

fTemp. avg \Temp. max.... No failure /Temp, max-.- ITemp. avg Hole through

-

/Temp, avg (Temp. max...

Temp. avg.

Hole through

-

No failure

ITemp. maxiTemp. avg.-

fTemp. max- ITemp. avg..

fTemp. max.-. \Temp. avg

Hole through.. do No failure fTemp. max... (Temp, avg

Ignited -waste. fTemp. max... ITemp. avg Hole through

-

No failure Temp. avg.. Temp, avg.- fTemp. max

\Temp. avg.. /Temp. max. ITemp. avg.. (Temp. max.

fTemp. avg__

Temp. avg.

/Temp. max. ITemp avg..- /Temp. max. ITemp. avg-- /Temp. max.

ITemp. avg-- /Temp. maxiTemp. avg-- No failure..-. /Temp. max.

ITerap. avg . fTemp. max- ITemp. avg.-

Time

mm

62

5870

65

70

5858H

62

48H

56

49

6163m

67 U7

131 '/2 136

47

751^

136

83

117

124

164

166

127!.: 134

Notes

4 X 4 ft panel.

25-min. fire exposure.

\ Portland cement scratch coat had 3 lb of asbestos

1 per bag of cement. 60-min. fire exposure.

30-min fire exposure.

|l/ath had corrugated perforated-paper backing. /Lath had corrugated perforated-paper baclcing.

\ 30-min. fire exposure. >Lath had corrugated perforated -paper backing.

4 x 4 ft panel.

1 X IH in. sheet-steel H supports.

30-min. fire exposure.

'l^i X U'a in. sheet-steel H supports.

30-min. fire exposure. Do.

Do.

^Thickness at point of failure, 2^6 in.

40-min. fire exposure.

30-min. fire exposure.

121 144

74

4 X 4 ft panel.

t Do.

\ Do.

4 X 4 ft panel.

jsrown coat plaster spalled from fire exposed side

1-hour fire exposure.

1 Thickness at point of failure by temp. max. I'Ms

/ in. Mix, 7 gypsum to 1 wood sawdust.

>Mix, 6 gypsum, 1 sawdust, 0 sand.

31
Table 5.

Solid plaster partitions with incombustible framing and

Test No.

49

60

XI

37

79

80 X2

81

82

125

138

139

Thickness

2%

m

2

2

2

21/2

21/2

2H

2H

21/2

2H

Sketches

ASBESTOIATH (Mj PLASTJER

SUPPORTS

Same design as 49.

1 /METAL LATH /PLASTER

\ CHANNEL STUDS

Same design as XI. ..do

...do.

...do...

....do...

.do. / GUNITE

"f^ ^WELDED FABRIC Same design as 124.

.do.

do.

Kind of lath

'4-in. asbestos lath (medium).

.do.

Expanded metal.

.do.

-do.

do.

do.

.do.

.do.

Welded fabric (4 x 4 x No. 6 wire).

-do.

-do.

.do.

Plaster

Kind

Wood-fibred gypsum .

.do.

Portland cement..

.do.

.do.

.do.

.do.

.do.

.do.

-do

-do.

.do.

.do.

Scratch coat

:12:2

1:2.

1

1:1:4

1:2

1:2

1:2.

1:2

*1:2.3

1:3.4

1:3.

4.5:1:6.9

Brown coat

86:12:2

86:12:2

1:3.3

1:1:4

1:3

1:3

1:3.3

1:3

•1:3.4

1:4. 25

1:3.4

1:3.1

4.5:1:6.9

•Calcareous sand.

[32]
incombustible or partly combustible lath; nonbearing—Continued

Test No.

Plaster- Continued

Finish Compressive strength

Tests

Kind of test

Failure

Kind Time

Notes

X2

124

125

138

139

White

-

.do.,

Float

-

TrowelFloat-..

do.. do-

_do.

.do.

.do-

.do-

-do.

.do.

lb/in."

560

560

1,820

1.000

4, 320

2, 770

4, 950

3, 050 1,820

1,000

4, 070

3,310 6,280

4,980

2, 760

..-.do

Fire and hose.

Fire endurance.

.do.

I -.do.

J-Fire endurance..

-

Hose test iFire endurance. do

Fire endurance... Hose test

Fire endurance..

3,130 do-

.do.

I Temp. max. \Temp. avg..

No failureTemp, avg.

/Glow in waste..

I Temp, avg /Temp, max

ITemp. avg Temp max No failure Temp. avg.. /Temp. max. \Temp avg... /Temp max.. \Temp avg... No failure..

-

,'Hole through. \Temp. avg

jFire endurance iHose test

Hole through.

r do

\ Glow in waste. [Temp, max

ITemp. avg No failure

133 142

3336

28'/:

36

38! 33

36

16

261/i

701/2 79%

%X 1% in. sheet-steel H supports. 7 gypsum to 1 sawdust, plus 2% asbestos.

J^x V'i in. sheet-steel H supports. 7gypsum to 1 sawdust, plus 2% asbestos. 30-min. fire ex- posure.

4 X 4 ft panel.

1 cement, 1 hydrated lime to 4 sand.

30-min. fire exposure.

4 X 4 ft panel.

60-min. fire exposure.

) Gunite spalled with explosive violence.

Gunite spalled with explosive violence. 6 lb. of asbestos per bag of cement added to mix.

|-Gunite spalled with explosive violence.

^Mix., 4.5 cement. 1 wood sawdust ,6.9 sand.

82-min. fire exposure.

33
relatively early failure in test 105 of a 2%-m.-

thick partition was caused by spalling of plaster on the fire-exposed side, which might have been

due to lack of bond between plaster coats,

imperfect set of the plaster, or excess moisture

at the time of test. The partition had been

seasoned for 30 days, June 12 to July 12, 1937.

In partition 121A, a half part of sand was

added to the neat plaster in an effort to obtain

better workability than for the neat woodnoted above. For partition 34 with 6:1:6

gypsum-sawdust-sand mixture, the fire resist- ance was about 40 percent more than was

obtained on the average for solid partitions

made with the 1 : 2 sanded plaster.

(c) Metal-Lath Base, Portland Cement Plaster

The fire resistance of 2-in. -thick solid partitions of Portland cement plaster was indicated

to be near 30 min (tests Xl, 78, and 80, table 5).

Figure 15. —Welded fabric with corrugated perforated-paper backing; test 56 before plastering.

fibered plaster. The limiting temperature rise was reached at 1 hr 57 min. as compared with

2 hr 44 min for a similar partition of neat

wood-fibered gypsum plaster (No. 116A). In

partitions 32 and 34 with sawdust admixture,

the plaster proportions were respectively the same as for hollow partitions 31 and 33. The

fire resistance of partition 32 was nearly comparable with what was obtained on the average

for neat wood-fibered plaster in the other tests

Only a minor increase obtained for similar

partitions 2}^ in. thick (tests X2, 81, and 82),

the fire resistance for both thicknesses being

limited by disruptive spalling of plaster on the

fire-exposed side, and in some cases on the

unexposed side. They successfully withstood

the hose-stream test at the end of the fire- endurance test. The calcareous sand used in partition 82 contained 60 percent of siliceous

minerals. In test 37 with a 1:1:4 cement-

[34]
I lime sanded plaster, similar disruptive effects were noted.

The plaster for the above partitions was

applied in the usual way with the trowel. The

large partitions were kept damp for about a week after completion, to insure plaster of high

strength, and were then seasoned under room

conditions for about 4 weeks. Partitions for

tests 124, 125, 138, and 139 were constructed

by spraying the mortar agauist a board backing

ing period, ])ii,rtitions 138 and 139 were aged for

4 months before testhig. The longer seasoning

did not prevent the violent disruptive effects in test 138 that limited the fire resistance in

this and earlier tests. Only a minor amount

of cracking and no spalling occurred in the test

of partition 139, which contained a volume of

sawdust approaching in bulk measurement that

of the sand. The end point in the fire-endur- ance test, TOYi min, was defined by temperature

Figure 16.- -Exposed side of partition of portland cement, sand, and sawdust concrete after fire-endurance and hose-stream

tests; test 139.

in jets propelled by compressed air. A coarser sand was used than for the trowel-applied

plaster. The first two were aged for 8 weeks

during the winter season in a heated laboratory.

The disruptive effects during fire exposure were more violent than for the trowel-applied plaster,

the fire endurance being limited by holes caused

by spalling on both the fire-exposed and unexposed sides. To obtain information on the effect of adding

sawdust to the mix and also of a longer season

rise on the unexposed side, and subsequent

thereto the requirements for a 1-hr rating were met in the hose-stream test (fig. 16).

6. Partition Facings as Protective Finish

Over Combustible Framing

Measurements of the temperatiu-e on the

edges of the studs toward the furnace during

tests of wood-framed partitions indicated the

effectiveness of the facings in affording pro-

[35]
tection to combustible members (table 6). In

conformity with the test specifications, the

limit of protection is assumed to be reached

when an average temperature rise of 250 degrees F above the initial temperature occurs on the face of the wood sujjports, or a rise at any one thermocouple location of 325 degrees

F. Tests 60 and 128 were made on partitions

faced with pulpboard; No. 61, with pulpboard

given flameproofing treatment; and Nos. 90,

127, 131, and 135, with gypsum wallboards,

all without plaster. All other tests listed in

studs as a result of the mineral-wool fills between studs was not discernible from test data.

In general, only three thermocouples for each

partition or section thereof were used for the

determinations. Considering the large local variations in cracking, spalling, and other

efl'ects on the fire-exposed side, variations in results due to accideTital conditions should be

expected to be larger than for the temperature

measurements on the unexposed surface, which

were generally made at nine locations. The

tabulated summary of results presents, however,

a general indicatioji of the eft'ectiveness of board

Table 6.

Partition facings of boards or plaster as fire-protective finishes over wood framing

[The plaster mix was proportioned by weight of dry plaster to dry sand]

Test No.

60, 128_

61

127, 131 135-

5958

53

129, 133

43, 44, 142

134 136A, 136B

1, 2

13, 14, 115

16, 17, 78, 89, 96, 120,

123.

54, 55

64, 65, 76, 77

104A. 104B

93, 94

118, 119 107A, 107B

130, 132, 143

20, 21, 22, 74, 110

144 42

40, 41, 51, 52, 137 95

75, 84, 85, 86, 87, 88.,

Plaster

Kind

None

do.__.

do...-

do.... Gypsum.

do... do...

do.... Lime

do.... Lime and Keene's cement . Wood-fibered sypsum Gypsum

....do

.do. -do.

.do. .do- Wood-fibered gypsum

do Gypsum

do

do Lime Lime and Keene's cementPortland cement gypsum_.

Portland cement

Scratch

coat Browncoat

1:2 1:2

1:2 1:2

1:2 1:2

1:2 1:3

1:5 1:7.5 1:6W 1:6M

3:1:8 3:1:12

2:1:6 2:1:9 Neat Neat

1:2 1:2 1:2 1:2

1:2 1:2

1:2 1:2

1:2 1:2

1:2 1:3 Neat Neat

Neat Neat

1:2 1:2

1:2 1:3 1:2 1:3

1:5 1:7.5

1:6.5 2:1:12.5

1:2 1:3

1:2 1:3

Thickness

H

H to 3/4

1 ?4 to 1

Yi to lii

Kind of lath

H-in. fiberboard

'/2-in. fiberboard, flameproofed

5i-in. gypsum wallboard

Vi-ra. gypsum wallboard

i/4-in. fiberboard

Vi-m. fiberboard, flameproofed.

%-in. fiberboard, flameproofed Wood

do

do..

.do. Gypsum

do

Perforated gypsum.

Indented gypsum

Indented and perforated gyp- sum.

Paper-backed wire or metal.

.

do Expanded metal do

do

do

....do

...-do

-.--do Wire Expanded metal

Thickness

of facing

ViH

Vi

1

1 %

% to 1

H

1 Vi to %

Limit as surface

finish over wood

Maxi- mum

18^2

1720

1032

281/. 3521M

32

2129

38

301/2 17

14

Mini- Aver- mum

nrnn.

3

12

14

10

24

2126H

211/2 25

19

19

351/2 27

13K2

126H

mm.

51/

121/2 10

16

21

1532

141/2 nh

61028

24

3021H

this table were with partitions having plaster

facings. It is seen that the board, gypsum,

and paper-backed metal laths in combination

with their plaster facings gave somewhat higher

protection than plaster facings on the plain

metal lath, even considering the difference in thickness. This might be due to the better

barrier afforded to the passage of hot gases during the first part of the test, as compared

with plaster facings made more or less open by

shrinkage cracks from fire exposure. Any

difference in the protection afforded by the

fire-exposed facings to the edges of the wood

facings, plastering bases, and plastering materials of the various types in protecting combustible construction against high temperatures

and ignition.

7. Deflection and Stability

The deflections of the wood-stud partitions were characterized by a slight bending toward

the fire during the first 5 or 10 min. of fire ex- posure, followed by deflections away from the

fire. This can be ascribed to the initial expansion of the fire-exposed plaster, causing deflec- tion toward the fire, which, as the test pro-

[36]
gTessed, was more than offset by the o-reotor shrinkage of the wood on the fire-exposed side. Few of the wood-stud partitions 10 to 11 ft. higli

tested without appHed load, deflected more than

2 in. before faihire occurred by rise of temperature on the miexposed surface. The load-bearing partitions, however, deflected more sharply

away from the fire and, for the most part, failed under load before the limiting temperature rise on the surface had been reached.

The deflections of steel-stud partitions were

toward the fu-e from the start of the test and more pronoimced than for wood-stud partitions.

The hollow partitions framed with 3/^-in.-

deep integral steel channels and faced with

sanded gypsum plaster deflected a maximum

of 1% to 3% in., whereas those of comparable

thickness framed with %-in. channels on each

side, tied together and spaced with horizontal

metal clips or rmmer channels, developed maximum deflections of 5]^ to 6}^ in. The sectional steel waU (test B1 9 ) had deflected

5.1 in. toward the fire at the time the limiting

temperature rise was reached at 28 min. At

35 min. the deflection was 5.5 in., at which value

it remained until the flre was stopped at 45 min.

The recovery on cooling ranged from 78 to 100

percent at the various pomts. The wall re- tained a satisfactory degree of stabflity throughout the test. The greatest deflections were found in the

tests of solid plaster partitions 2 to 2J2 in. thick.

The midpoint deflections of nhie such partitions

of sanded gypsum plaster on metal lath average

6.2 in., and four of the nine partitions deflected

in excess of 8 in., the fire-exposure periods aver- aging 62 min. The deflections of five solid

partitions of neat wood-fibered gypsum plaster

averaged 5^2 in. after exposure periods averaging over 2 hr. The average deflection of three

solid partitions of sanded portland cement

plaster was also 5)2 in. after an average exposure

tune of 33 min.

The studs of wood-framed partitions were

nailed into top and bottom 2- by 4-in. wood

plates, secured to the panel frame with bolts

screwed into expansion shells. The channel

studs of metal-framed partitions were tied at the top and bottom to runner channels, which

were secured to the panel frames with bolts, concrete nails, or similar means. In no case

with partitions tlius secured did tlie deflections

of nonbearing partitions cause instabilit}^ to an extent that it Umited the fire endurance or hose-stream resistance of the construction.

However, in test 45 no anchorage of the sheetmetal studs into the top and bottom runner

channels was provided, and with the high

deflection, about 8 in. near the end of the test, decided mstability was indicated, and the

partition collapsed completely at 1 hr 8 min.

For similar partitions constructed later, Nos.

140 and 141, the studs were tied to the runner

channels and two No. 10 gage horizontal wires on each side, tied to the studs and embedded in the plaster, extended the full width of the partitions. This considerably increased theh stability and integrity, the deflection being considerably lower and no openings of serious

import were formed on the line of the studs.

The deflections of the metal-framed partitions were apparently caused largely by the greater

expansion of the fire-exposed facing as compared with that of the other other side, although

general or local buckling due to restraint within

the panel frame was evidenced in a number of

tests. While lower deflections would be ex- pected for the thicker partitions, no consistent

dift'erence was found for solid partitions 2 to 2 Jo in. thick. For hollow partitions 4% to 7%

in. thick, the difference was withia the range

of variation obtaming for partitions of one

thickness.

V^lifle this paper is not concerned with the

strength and stability of these partitions except

as exposed to fu"e, these properties will imder

such exposure Yary from what obtams at the

start of the fire test to progressive impairment

as the test proceeds, some being near collapse

at the end of their fire-endurance period.

Accordmgly, it may be of interest to give an account of impact and loading tests with a 2-ui. solid partition 10 ft high, which as a type, would

be expected to have lower transverse strength

and impact resistance than most of the partitions in the series. It was framed on %-in. asbestos lath inserted mto No. 24 gage Hshaped sheet-metal supports on 18 in. centers,

and faced with 1 : 2 sanded gypsum plaster, being

sunilar in all respects to partition 47. Punching impact tests were made with a 100-lb weight swung on an 8 ft 9 in. radius to

[37]
strilce a wood disk 3 in. in diameter. The first fine craciv in the plastei- was noted after a swing

of 17 degrees, corresponding to a fall of about

4}2 in., the disk being driven %6 in. into the

plaster. Another similar impact, together with one with a swing of 20 degrees, caused a penetration of % in. and the opening of cracks up to

in. In the flexural impact tests, the same weight on a 5-ft suspension was swung against a 4- by

4-in. wood member placed horizontally at the

midheiglit of an 8-ft 4-ui.-wide section cut free at the sides from the rest of the panel. The

first blow with a swing of 37 degrees, corre- sponding to a fall of about 12 in., produced a

fine horizontal crack in the plaster on the opposite side near the horizontal center line. Repetition of this impact and two from an

angle of 45 degrees (17/2-in. fall) extended the

cracking and caused a set in the deflection of

}i in. Three further swings from 54 degrees

(24-in. fall) caused these cracks to open to a maximum of 0.01 in. and the set to increase to

}i in. Four blows from an angle of 65 degrees, or a fall of 34 in., caused vertical cracks to form on the lines of the studs and a permanent

deflection of 3K in., the panel being near

collapse.

The flexure test wa,s made with a vertical

section 73 in. wide, the thickness at midheight

on the line of loading being 2^8 in. A horizontal

thrust of 200 lb caused a deflection of 0.05 in., but no perceptible cracking of the plaster. At

300 lb the plaster cracked and the deflection at midheight increased to 0.3 in., which increased

to 0.75 in. at 400-lb load. This was the highest

load sustained, failure occurring at the next

load of 425 lb. The 300-lb load corresponds to a modulus of rupture for the plaster of 165 lb/in.

The flexural strength beyond this point in this as well as the flexural impact tests can be attributed largely to the resti'aint within the rigid

panel frame in which the partition was built,

the deflection of the panel inducing end thrusts

that balanced the increments of moments beyond those producing rupture. of the plaster in tension. Similar restraint can be expected

where partitions are built between heavy structural floors in fire-resistive buildings.

VI. SUMMARY AND DISCUSSION

The principal results of the tests will be

summarized in tenns of fii'e-resistance periods,

based on the data given in tables 1 to 6. They

are defined (Appendix A) by the time of occur- rence of a temperature rise above the initial on the unexposed side of 250 degrees F, taken

as an average of all temperature determinations; a rise at any thermocouple location of 325 degrees F; passage of flame to the unex- posed side; or ignition of cotton waste placed

against it. For load-bearing constructions, fail- ure under working load is also a criterion. In

tests of such constructions that could be con- tinued beyond the time of faflure under load

until the limiting temperature rise on the unex- posed side was obtained, a rating as a nonbearing construction could also be given. The

results with the 4- by 4- ft partitions are considered only as supplementary to those obtained

with partitions of larger size. For a complete rating of 1 hour or more,

ability to witlistand the prescribed hose-stream

test after a flre exposure of a dui-ation not less than one-half of the rating period, but not more

than 1 hour, is also required. With some constructions the hose-stream test was not con- ducted and others failed in one or more trials. Notations relative thereto are made in the summaries.

Fire-resistance periods are taken 5 min apart

up to % hr, at 15-min intervals from % to 2 hr,

and at Yo-hx intervals for higher ratings. A

tolerance of one-fourth of an interval is allowed, a given period being taken if the average of results is above it by not more than threefourths or below it by not more than onefourth of the interval for the pertaining range.

While no general limitations on heights to which the different partition types can be used

is here given, it may be permissible to apply

them up to at least the heights in which they were tested. Thus partitions having 2- by 4-in. wood framing were tested in height of 10 ft 3 m.

under load and 10 and 11 ft as nonbearing.

Because of the low deflections, the height does

not appear to be an important consideration for nonbearing wood-stud partitions. Wood block-

[38]
ing was placed at the midheight to decrease the

free length of the wood studs as bearing members. The load applied, 360 lb/in. ^ of net area, conforms with accepted design standards for members of such proportions and is representative of the limit to which working loads should

be imposed. The deiiections of the metalframed partitions were higher, but as nonbearing constructions the needed stability can be

obtained by anchorage into the surrounding

construction. Such anchorage to the extent used for the test constructions is a necessary

condition for the ratings assigned.

1 . Board Partitions Without Plaster

The board partitions without plaster were all framed on 2- by 4-in. wood studs, except Nos.

101 and 102 (table 1) of solid built-up wood

construction, No. Bl7 of plywood panels, No.

Bl9 of steel panels, and Nos. 7 and 8 of gypsum

slabs. All but the last three partitions would

thus be classed as " combustible,'^ according to the last paragraph of the introduction to the

test specifications (Appendix A). While most

of the partitions listed in table 1 were not tested

under load, the results of other tests under

load, as well as the condition of the wood studs

after test, indicated that for fire-resistance

periods up to 20 min a working load would

have been supported. For longer periods this is uncertain unless such a load was applied and

sustained during the fire test. Wood and paper fiberboards of Yn in. nominal

thickness applied on both sides of wood studs can be taken to have a fire resistance of iO min,

if weighing air dry not less than 0.70 lb /ft

^

(test 128) ; and 15 min, if weight is not less than

1.20 Ib/ft^ (test 60). A similar partition construction with boards of the latter type, flameproofed to give added weight from retained

chemicals of about 50 percent of the original

weight, was indicated to have 30-min fire resist- ance (test 61), when tested nonbearing.

Wood-stud partitions faced with gypsum

wallboards, having a core of neat gypsum

plaster with facings of paper, and finished with

casein paint, can be given a fire-resistance rat- ing as a bearing construction of 26 min for boards % in. thick (test 90), and by comparison,

30 min, for boards in. thick (test 127). As a

nonbearing partition the latter can be rated

40 min. With the K-in. gypsum-board facings

and "full thick" or "wall thick" rock-slag wool

or glass-wool bats, 2% to 3K in. thick, in the

stud space, and weighing respectively not less than 1.2 and 0.6 lb/ft", the fire resistance is increased to % hr as a load-bearing construction

with the bats not secured with nailing, and 1 hr

with the fill thus secured (tests 131 and 135).

As nonbearing, the 1-hr rating will apply either

with or without the nailing.

The 3-in. -thick wall with plywood facings,

filled with mineral-wool bats weighing 2 Ib/ft^ and tested as a nonbearing partition, acliieved a rating of % hr. In placing mineral-wool fill to increase the fire resistance of partitions, care must be taken

that no void spaces are left and that the fill is distributed evenly over the stud space. Since,

in the form of bats, it is placed against one

partition facing before the other is applied,

inspection thereof can be made. The nailing

of the bats appears desirable and prevents

settling or displacement during the subsequent

application of facing or lath, as well as from

vibrations of the completed structure. However, in the test partitions with the fill not

secured, no settlement due to construction

conditions was indicated. The nailing also helps to hold the fill in place if the facing faUs

off from fire exposure. For fills in loose or nodulated form placed by pneumatic means,

void spaces in the fill may be formed by arching of the fill at projecting nails or splinters,

the control of uniformity and density is more

uncertain, and there is little opportunity for inspection after placement. However, this method is generally limited to application in

ex-isting buildings, since placement in the form

of bats or blankets appears to be more practical

for new construction.

Solid wood partitions, if of 2-in. tongue-andgrooved mill flooring (1% m. actual tliickness), can be rated 10 min (test 101), and if in two

layers of /4-in. tongue-and-grooved boards

placed with staggered joints, 15 min (test 102).

With 30-lb asbestos paper between board layers,

the rating for the latter is increased to 25 min.

Hollow partitions of 2- by 4-in. wood studs

faced on both sides with %-m.. tongue-andgrooved beaded wood ceilmg are rated 20 irvin:

[39]
the same construction but with bulk mineralwool fill in the stud space, 33 min; and with

30-lb asbestos paper imder the boards and no fill (test 103), Yi hr. The fire resistance of these

wood partitions was limited by the shrinkage

of the boards when exposed to fire, allowing

passage of flame and hot gases through the

joints.

The 2%6-in. -thick precast hollow slabs of neat

gypsum with tliiclmess of faces opposite cores

of %6 in. and hollow space 44 percent of the

area, as tested in the small furnace (tests 7 and 8) , were indicated to have a fire resistance of over 1 hour. While the deflections were small,

and stability in a 10-ft height for an hour or more of fire exposure in the large furnace would

probably be maintained, it is questionable

whether the requirements of the hose-stream

test could have been met after a 30-min fire exposure. On this accomit, as well as the small

size of panel, no definite ratmgs can be given,

although the results are informative as to the

performance of cast gypsum under fu"e. The 3-in. -thick wall of sheet-steel units filled with calcined vermiculite to the average density

of 6 Ib/ft^ (test Bl9) can be given a rating of 25 m.in as a nonbearing wall. Its ability to sustain load would be limited by the high deflec- tion and high temeprature of the steel near the

fire-exposed face.

2. Hollow Wood-Framed Partitions With

Plaster on Combustible Bases

The fire-resistance ratings for constructions

of this type, based on the data in table 2, are summarized in table 7 (A) . These are all rated

"combustible," accordmg to the test specifications, on account of the framing as well as the

plaster base. The studs of bearing partitions

rated in this and other groups in table 7 are assumed to be of not less than 2- by 4-in. nominal size, set edgewise on spacings not exceeding

16 in., and of No. 1 Common or better grade, as

classified according to American Lmnber Standards. For nonl)earmg pai'titions the grade is

less important, but the stock should preferably

be of grade not lower than No. 2 Common.

Wood-stud partitions faced on both sides with

/2 in. of 1:2 gypsum plaster over wood lath (test

M) and over K-in. -thick fiberboards weighing

0.7 Ib/ft^ (test N) have approximately equal

fire resistance. While the tests were not made

under load, the results of others tested under

load, with plaster facings of approximately

equal protective value (compare tests 58, 129,

and 133, table 6), indicate that the load would

be sustained for the /2-hr period. For a partition with a denser fiberboard as plaster base

tested imder load (test 59), the ^^-hr rating

applies within the permissible tolerance. With

1 : 2 sanded gypsum plaster over wood lath and

the stud space filled with mineral-wool bats, a fire-endurance limit of over 1 hr was attained,

but the rating is limited to 1 hr on account of the 30-min fire exposure preceding the hosestream application in test 133. A fire endur- ance of over 1 hour was also obtained with a

similar partition (No. 136), except that the

plaster was of lime and Keene's cement sanded

in the approximate ratio of 1 : 2 for the scratch

coat and 1 :3 for the brown coat. The rating is limited to 1 hr as a bearing partition and is incomplete since no hose-stream test was

conducted.

Partitions with a }^-in. thickness of lime plaster over wood lath, and without mineral-wool

fill, are rated K hr, and % hr with the fill in the

stud space, the ratings being based mainly on

the results with partitions having fairly dry

facings at the time of test, a condition that can

be assumed to obtain for partitions inside of buildings. While the unfilled partition was

not tested under load, comparison of the efl'ec- tiveness of its facing as a protection for the wood

studs with that of others tested under load (compare tests 43, 44, and 142 with 129 and 133,

table 6) , indicate ability of the partitions to sus- tain a load for the rated period within the limit

of variation in results obtaining for nominally

similar constructions in these tests.

[40]
Table 7.

Summary of fire-resistance ratings of plaster partitions

Plaster

Test No. Plaster base Kind

Mix, dry weight Rating

Scratch | Brown

(A) WOOD FRAME WITH FACING ON EACH SIDE OF THICKNllSS "D" OVER COMBUSTIBLE BASE. RATED AS BEARING PARTITIONS, COMBUSTIBLE

Wood lath or Yi-in. fiber- board weighing 0.7

lb/ft.2 y2-in. fiberboard weighing 1.1 lb/ft.2 J^-in. flanieproofed fiber- board weighing 7.8

lb/ft.2 Wood lath with mineral- wool fill, do. Wood lath without fill _ _

.

/Wood lath with mineral-

\ wool fill.

Gypsum and sanddo..__ do

_do. Lime and sand do

Lime. Keene's cement, and sand.

1:2

1:2

1:2

1:2

1:5

1:6 3:1:8

2:1:6

1:2

1:2

1:2

1:3

1:7.5 1:7.5 3:1:12

2:1:9

D=>A in. y> hr. % hr.

1 hr.

1 hr. H hr.

'A hr. kl hr.)3

(B) WOOD FRAME WITH FACING ON EACH SIDE OF THICKNESS "D" OVER INCOMBUSTIBLE OR PARTLY COMBUSTIBLE BASE. RATED AS BEARING PARTITIONS, COMBUSTIBLE, EXCEPT AS NOTED

1, 2

16, 17,89, 96, 123 F, 13, 14, 54, 55, 64, 65,

76, 77, 78, 120. 115 --

20, 21, 22, 74,110 93A,93B,94A, 94B_

95

97A, 97B, 97C, 104A,

I04B.

130A, 132

107A, 107B, 118, 119. 42

109

40, 41, 51, 52.

137

75, 84, 85, 86.

87,88

%-in. gypsum, plain %-in. perforated gypsum

'

?i-in. gypsum -

%-in. gypsum, plain, with metal-lath pads. Expanded metal Paper-backed metal Metal Expanded metal Paper-backed metal. Expanded metal

mineral-wool fill. Expanded metal . .

.

do

do

with

.do. Expanded metal with

mineral-wool fill. Expanded metal

.do.

Fibered gypsum ».

.

Gypsum and sand.

...-do

.do.

-do.

.do. Portland cement, gyp- sum, and sand. Gypsum and sand

do

.do.

Fibered gypsum s Lime and sand

Lime, Portland cement and sand. Lime, Keene's cement, and sand. do

Portland cement and

sand. Portland cement, asbestos fiber, and sand.

Neat

1:2 1:2

1:2

1:2

1:2

1 Portland: 2

1:2

1:2

1:2 Neat

1:4 2:1:8

2:1:8.

5

1. 5:1:10

1:2

1:1/30:2

Neat

1:2 1:2

1:2

1:3

1:3

1 gypsum: 3

1:2

1:2

Neat

1:7.5 2:1:10

2:1:13

1. 5:1:15

1:3

1:1/30:3

D=H in.

1 hr H in. in.

1 hr

1 hr (lhr.)<—

-

3/4 hr

(1 hr.)<....

1 hr

1 hr

(1 hi.)i

1 hr IMhr

11/2 hr H hr (1% hr.)6. Hhr

(IH hr.)3 Hhr Mhr

% hr 1 hr

(C) STEEL FRAME, HOLLOW, WITH PACING ON EACH SIDE OF THICKNESS "d" ON INCOMBUSTIBLE BASE. ALL RATED AS NONBEARING PARTITIONS

18, 19,72,111.

73

23, 25, 26, 36, 38, 39.

24122A

33

31122B,126A, 126B.

98

83

Expanded metal,

----do

-do.

-do.

-do. .do.

.do.

-do- .do.

.do.

Gypsum and sand Gypsum and calcareous sand. Gypsum and sand

do.

.do. Gypsum, sawdust, and

sand. Gypsum and sawdust

Fibered gypsum s Portland cement, gyp- sum, and sand. Portland cement and

sand.

1:2

1:2

1:2

1:1. 6 1:1/2 6:1:6

7:1 Neat

1 Portland: 2

1:2

1:3

1:3

1:2

1:1.5

1:1/2 6:1:6

7:1 Neat

1 gypsum: 3

1:3

Z>=H in. Vi m.

?4 hr...

(lhr.)3.

1 hr aVi hr.)3

(Ui hr.)3 Vyi hr..-

1 hr Mhr.

% in.

114 hr.

(1 hr.)

2'hr.""

(2 hr.)3

2H hr.

See footnotes at end of table.

[41]
Table 7.

Sumviary of fir(-resistance ratings of -plaster partitions—Continued

Plaster

Test No. Plaster base Kind

Mix, dry weight Rating

Scratch j Brown

(D) STEEL FRAME, SOLID PARTITIONS OF THICKNESS "D." INCOMBUSTIBLE OR PARTLY COMBUSTIBLE BASE. ALL RATED AS NONBEARING PARTITIONS

141 _

46, 46, 140- 47

49, 50 X4, X5, 29, 30, 56, 62, 63,70,71,112. X8, 27, 28, 36, 66, 67, 68,69,91,92, 114. 34

32121A

X7, 105, 106, 116A,

116B, 117, 121B.

113

37_ XI, X2, 7(1, 80, 81, 82.

124, 125, 138

139 _

1-in. wood fiber and mag- nesium oxysulfate

board. do

%-in. asbestos lath (soft). 'H-in. asbestos lath (me-

: dium). Expanded metal or per- forated paper-backed welded fabric. Expanded metal

.do.

.do.

.do.

.do.

.do.

.do.

.do. Welded fabric 4 x 4 in. No. 6 gage wire.

.do.

Gypsum and sand.

....do

...do Gypsum, sawdust,

asbestos fiber. Gypsum and sand.

.

and

.do. Gypsum, sawdust and

sand. Gypsum and sawdust Gypsum and sand

Fibered gypsum 5

Portland cement, gyp- sum and sand. Portland cement, lime, and sand. Portland cement and

sand. Portland cement and

sand, dense, sprayed

on. Portland cement, sawdust, and sand, sprayed

1:2. 5 1:2 86:12:2

1:2

1:2

6:1:6

7:1

1:1/2 Neat

1 Portland: 2

1:1:4

1:2

1:4

4.5:1:6.9

1:1

1:2. 5 1:2 86:12:2

1:3

1:2

6:1:6

7:1

1:1/2 Neat

1 gypsum : 3

1:1:4

1:3

1:4

4.5:1:6.9

Z)=2in.

¥i hr

H hr.

Vi hr.

Vi hr.... (mhr.)3

m hr.

H hr.

V4 hr.

2H in.

f(2hr.)3. U hr....

(lhr.)«.

(1 hr.)4..

(2 hr.)3 {2hr.)3 2hr... H hr.

2M2 in.

1 hr.

1 hr.

1 hr.

2H hr.

Khr.

1 hr.

1 Perforated with holes ^ in. or larger, 1 hole for not more than 16 in.^ of area.

2 Plain lath, indented lath, or lath plain or indented, with perforations not conforming with those referred to in footnote 1.

3 No hose-stream test.

' Hose-stream resistance not adequate according to present test specifications.

' The fiber in neat fibered gypsum plasters can be wood, sisal, asbestos, or mixtures thereof.

6 Rated as nonbearing.

3. Hollow Wood-Framed Partitions With

Plaster on Incombustible or Partly

Combustible Bases

(a) Variations iv Results Due to Thickness

For this and the remaining groups of tests of plaster partitions, there were introduced variations in the thicl^ness ol the plaster. Also,

incidental variations from failure to attain the

intended thickness accounted for variations in average thickness up to Ys in. for facings of hollow partitions and up to % in. for solid partitions, with somewhat greater difi'erences for individual locations on the panel. For hollow

partitions, the significant thickness is the combined thickness of the facings, although the air space and any plaster keys extending beyond the

back of metal lath are contributing factors. From plotting the average thickness of solid materials for comparable partitions against the

time required for the limiting average tem])era- ture rise to occur on the unexposed surface, it

was concluded that the latter varies approximately with the 1.7 power of the thickness,

which was applied in limited interpolation and

extension of test results to obtain some of the

ratings in table 7. The indicated relation is in general agreement with what would be expected

from theory,^ according to which, assuming a constant exposing temperature on one side, the

time required for a given temperature rise on

tke opposite side is a function of the square of the thickness. The rising furnace temperature

incidental to the standard fire test gives a higher average exposing temperature in tests of the longer durations, which has the eft'ect of decreasing the influence of thickness indicated

in such a comparison below what would obtain

for a constant exposing temperature.

To attain fire resistance for given nominal

thicknesses comparable with the ratings herein

given, due care need be taken that the intended

' Ingersoll and Zobel, Mathematical Theory of Heat Conduction,

pp. 78 and 108 (Ginn and Co., 1912). W. H. McAdams, Heat Transmission, pp. 26-40 (McGraw-Hill Book Co., Inc., 1933).

[42]
average plaster thickness is obtained and that

the variations in thickness are not excessive.

While the full thickness may obtain or be ex- ceeded at the grounds, in finishing with float and trowel there is a tendency for the surface to become dished between grounds, and the use of intermediate screeds may be necessary to prevent this.

(b) Partitions With Gyjjsum Plaster Bases

The gypsum plaster bases in the form of plaster boards or lath, about % in. tliick, consist of a core of neat gypsum with paper facings.

For the ratings concerned, they may be placed

edge to edge or % to % in. apart. The weight of the perforated lath for the partitions having

1 hr. or greater fire resistance was in the range

1,530 to 1,725 lb/1,000 ft.^ That for test 96 was 1,400 lb, and while this may have contributed to the lower fire resistance, the low strength

of the plaster was probably a greater factor. To qualify these partitions for the 1-hr rating,

the plaster must be of the higher range in strength and of a proportion not leaner than

1 : 2 by weight, applied in Yi-in. thickness. The

plaster strength appears to aft'ect the bond and

general stability of the facing when exposed to

fire. Slow-setting plaster to which an accelerator had been added appeared to give less favorable results than that not thus processed.

The lath for the partitions in the tests on

which the above ratings are based (Nos. 16,

17, 89, 96, and 123) had perforations not less than % in. in diameter, one for not more than

16 in.^ of lath surface. Indentations and holes

of smaller diameter or of less aggregate area did

not appear to effect much improvement over

the plain lath, although, due to vaiiation in the

strength of the plaster, the eft'ect of such details was not definitely determined. The 1 -In- rating was also attained with metal-lath pads

nailed over the surface of plain gypsum lath, one for not more than 128 in.^ of surface.

(c) Wood-Stud, Metal-Lath Partitions

The metal lath in most of the tests was of the flat, expanded type, weighing from 2.2 to

3.4 lb/yd.2 In one test, No. 95, the lath was

of woven wire. While the weight of the lath

had apparently little influence on fire resistance.

the heavier lath is without doubt preferable

fi-oni the stiuidpoint of dui-nbiiity, particularly

in hollow piulitious wliere tlu^ lath is partly

exposed on tlu' iniuT side of the facings. The

papcr-biickcd laths included both expanded

metal and welded wire, the one for test 97

being of the corrugated typo. The thiclmess

of plaster is taken from the hack of the lath,

and in the case of paper-backed lath, the aver- age thiclmess outside of the paper backing.

Such comparisons as were made did not indicate

any essential difference in results with the

different types of lath included, assuming equivalent thickness of plastei'. The derived rat- ings given in table 7 (B), however, should not

be taken to apply for laths that are essentially

diifei'ent in design and materials.

{1) Gypsum plaster.—Tlie partitions in this classification with facings of %-in. thiclaiess of gypsum plaster sanded 1 : 2 for the scratch coat and 1:3 for the brown coat applied on expandedmetal lath (tests 48, 60, 63, table 3) mdicated

average fire endiu-ance barely within the toler- ance limit for the 1-hr rating, but similar partitions (tests 22 and 110) failed in the hosestream test. Such failure also obtained in test 144 with a %-in. thickness of plaster. The

average fire endurance of similar partitions

with plaster applied on paper-backed lath was

a little below this tolerance limit, although

passing the hose-stream requirement (tests 93

and 94).

While no fire-endurance tests of similar woodstud partitions were made with thicker plaster

facings, the discussion on the effect of thiclmess on fire resistance given above indicates that an

increase in thickness of facings to % in. should

increase the fire-endurance limit of t ie partition

to a little over 1 hr. As applied on paperbacked metal lath, the required hose-stream

resistance was indicated to obtain for a thick- ness less than % in. (test 94). Considering the

results noted above for the %-in and %-in. thicknesses applied on plain metal lath, the

required hose-stream resistance with this plaster

base cannot be assured even for the %-in. thickness. The 1-hr rating applies foi' this plaster thickness and mixture ratios if portland

cement with additions of hydrated lime and

asbestos fiber is substituted for gypsum in the

scratch coat (test 95).

[43]
For 1:2 proportions of plaster for both

scratch and brown coats, the }^hr rating for the

)^-m. thicloiess is based on results in test 97,

which are consistent with the general considerations governing the effect of thickness on fire resistance discussed above. For the %-ui. thickness the fire-endurance limit was indicated

to be a little over 1 hr and the hose-stream

resistance, as far as that applied on paperbacked metallath is concerned, can be taken as proved in test 94. However, with the plain

metal lath, the hose-stream requirement was

not met (test 143), failure occurring 1 min 36

sec after the hose-stream application was begun.

Further information on the effect of mixture

ratio and strength of plastei' on hose-stream

resistance was obtained with metal-stud partitions as noted in the next section.

With the 1:2 proportion for the full ?^-in. thickness of the gypsum-plaster facings and

the stud space filled with mineral-wool bats,

the fire resistance is increased to IK hr. The

same result is obtained without mineral-wool

fill by the use of unsanded gypsum plaster, with

fm-ther increase up to 2 hr for 1-in. thickness

of facings. The partitions with neat plaster were tested without application of load during

the fire exposure, and because of this and their

weak condition at the end of the fire-endurance

tests, they are rated as nonbearing.

(2) Lime plaster.—A fire endurance of 36

min was obtained with lime-plaster facings

applied to %-in. grounds with indicated thick- ness a little less than % in., the y2-hr rating

being taken to apply for the %-in. thickness.

With lime plaster the fire resistance is limited more by spalling of plaster than by thicloiess

of facings. The plaster was seasoned so that

most of the excess water had been given oft", but in this time little carbonation of the lime

would take place. However, as noted else- where (section lV-3 (d)), little increase in fire resistance of lime plaster is to be expected from

the small amoimt of carbonation that normally

takes place over a period of years. Accelerated

carbonation by any method so far found practical of application in buildings, wliile increasing

the hardness near the surface, apparently

results in no decided increase in fire resistance.

(S) Portland cement plaster.—Fire resistance

with Portland cement plaster facmgs was also

limited to some extent by spalling of the plaster on the fire-exposed side. However, good re- sistance in the hose-stream test was indicated.

The addition of short-fiber asbestos decreased

the cracking and spalling and the 1-hr rating

is assigned for the %-in thickness, assuming

addition of not less than 3 lb. of asbestos per

bag of cement.

4. Hollow Steel-Stud Partitions

The ratings for this group are given in table

7 (C), as derived from results for individual partitions given in table 4, all being rated nonbearing on account of the framing.

The %-hr rating for gypsum facings applies

for %-in. thickness with 1:2 mixture ratio for the scratch coat and 1: 3 for the brown coat, on account of the average fire-endm'ance limit and

also failure in the hose-stream test in one out of two trials. The 1-hr rating for the above conditions was attained with the use of calcareous

sand (test 73) in place of the high-silica sand

used for most of the test partitions in this

series. The substitution of asbestos-fibered

Portland cement for gypsum in the scratch coat

also improved the fire resistance (test 98), and

there was also definite improvement eft'ected by applying the 1 : 2 mixture ratio for the full thiclmess of gypsum-plaster facings.

Substituting sawdust in whole or part for the

sand did not result in any decided change in fire resistance as applied for these hollow partitions. The neat and lightly sanded gypsum

plasters, however, gave decidedly higher fire resistance, the former a little higher than for similar plaster applied in wood-stud partitions.

The results with portland cement plaster were

similar to those obtained with this piaster in wood-stud partitions.

5. Solid Plaster Partitions

The ratings derived for partitions of this type, based on the test data in table 5, are given in table 7 (D). Reference is also made

to section V-5 for further information on the

partition constiuctions and details of test

results. The partitions are all rated nonbearing, and while some of the plaster bases were

partly of combustible materials, no flaming fi'om

them was observed either during or after the

[44]
I

lire exposure. Accordingly, they need not be

designated as "combustible."

With the board plaster bases % in. and 1 in. thick, faced with 1:2 or 1:2)^ sanded gypsum

plaster, the fire resistance was a little less than

for equal over-all partition thickness of the same

plaster throughout, although assigned substantially the same ratings because of the rating

intervals applied. There were, however, indications that they have better resistance to the

hose stream. Because of failure of 2-in. and

2Yi-m. thick partitions of 1:2 or 1:2 and 1:3

sanded gypsum plaster applied on metal-lath

bases to pass the hose-stream tests (Nos. 62,

112, 36, and 67), the unqualified 1-hr rating can

be given only to those 2}^ m. thick, even considering that one out of three 2-in. partitions

of 1:2 plaster throughout of good strength (No.

91) passed the hose-stream requirements. For

the 2)2-in. thickness the hose-stream resistance

for the 1-hr rating was established in two tests (No. 71 and 92), although there was failure to establish hose-stream resistance for rating

higher than 1 hr (test 69).

Partitions of neat fibered gypsum plaster 2 to 2% in. thick rather consistently indicated fire resistance of approximately 2 hr with the

exception of No. 105, which failed because of spaUing of plaster after a little more than 1-lir

fire exposure. This is the greatest incidental

variation encountered in this series of tests, and

any cause that can be assigned for the low

result does not wholly preclude the possibility

that such performance cannot obtain for partitions built under the usual conditions in building construction. The ratings assigned for the

neat plaster are somewhat below the average of

test results, which included the given low value.

The maximum variations in test results with

other nominally similar constructions in this

series correspond to differences in average fire resistance of % hr. With 7 parts of gypsum plaster to 1 part of sawdust by weight (test 32), the fire resistance was indicated to be only slightly less than for a comparable thickness of neat plaster. A little greater reduction, although with results still within the range applicable for the same rating

period as that for the 7 : 1 mixture, was obtained

with 1 part of gypsum to part of sand (test

121A). The ratings for these partitions are

incomplete, since no hose-stream tests were

conducted,

Portland cement plaster as a base coat for gypsum plaster (test 113) did not give as favorable results as in hollow partitions, the

difterence probably being due more to the

properties of the plaster and its bond with the

base coat than to the type of partition. Even

so, the results are comparable with those

obtained with 1 : 2 sanded gypsum plaster for the scratch coat. The fire resistance with

Portland cement-lime sanded plaster and portland cement sanded plaster was limited to K lu" because of cracking and spalling. This was

even more pronounced with a dense mixture

sprayed in place by pneumatic means (tests

124, 125, and 138). A decided unprovement

was obtained with the latter by substituting

sawdust for about one-half of the volume of the sand in the mixture (test 139).

6. Partition Facings as Protection for

Combustible Supports

Table 6 gives a summary of the limits of protection given wood supports by the fire-exposed

facing when tested in a partition with the same

facing on the unexposed side. These are with

few exceptions within the range one-sixth to one-third of the fire-endurance limit of the

respective partitions as tested without fill in the

stud space. While the attained temperatures

corresponding to these limits of temperature

rise are somewhat below those at which wood

will ignite, the temperature records (see figs. 10

and 12) as well as appearance of flame indicated

that the wood supports were well ignited at a time no more than one-half of the fire-endurance

limit of the partition. If the partition is adequately fire-stopped at the top and bottom,

which, with proper methods can be attained even if floors above and below are wood-framed,

the facing on the unexposed side will continue

to function as a fire barrier, at least up to the

fire-endurance limit of the partition.

7. Resistance to the Hose Stream

The hose-stream test is intended to determine

resistance to pen^ration of hose streams that

might be directed against the construction in the course of fire-extinguishing operations not

[45]
resulting in extinguishment of the fire. The

occurrence of such conditions is apparently not

very frequent, since it would be expected that

under most conditions water in sufficient quantity to cause this damage would also extinguish

the fire or subdue it to an extent that it will not rekindle and burn actively before more

water can be applied. The test may yield some incidental information on the stability of the construction and its component parts.

8. Significance of Fire-Endurance Limits

As indicated above, the actual protection

given by a partition construction may be less than the rated fire-resistance period because of passage of fire around the borders of the partition. To prevent this occurrence, the spaces

in wood framing must be suitably filled or fitted,

preferably with incombustible materials. Fill- ing the stud spaces of the partition can only

retard communication of fire from the partition into surrounding open spaces in floor, wall, or partition construction. Even with such

spaces fire-stopped, unless extinguished, the

fire would eventually be communicated to the

surrounding parts of the structure if of combustible materials and result in destruction of the

building or the portion thereof within the bounding exterior, party, or fire walls. Hence, the

protection, while important in retarding the

spread of fire in buildings of this type, is to this extent of a limited nature. The protection given by incombustible partitions fitted in buildings having structural members of incombustible materials can also be

limited to less than the fire-endurance periods

indicated in these tests by failure to provide

proper ties or support at the borders. It is evident that if placed on combustible finish

floors, the fire coidd pass under them and also impair their stability. Even if built on incombustible floor fill or supported into hung plaster

ceilings without direct support on the structural

floors above and below, stability for the full protection period of the partition is not assured.

The impact and flexure tests indicated that

thin, solid partitions obtain a considerable

margin of strength from such support on rigid

structural members.

The temperatures determining the fire-endur- ance periods were taken imder asbestos pads to

prevent the incidental variations inevitably in- cuiTed if attempts are made to determine temperatures on the free surface, and to simulate

in a degree the tem.perature that might obtain

if combustible materials and finish are in contact with the side not exposed to fixe. While such ]^iles of mateiial might present more

favorable conditions foi' temperature rise than

the asbestos pads, it is noted that even assuming room temperatures up to 100° F, the

attained temperatures at the fire-endurance

limit are still somewhat below the ignition temperature of ordinary combustible materials,

such as wood, paper, and textiles. After fire exposures terminating at the fire- endurance limit, the temperatures on the unex- posed surface continue to rise (see fig. 14) and

combustible materials m contact, not pre- viously ignited, might then be set on fire. Accordingly, following fires in buildings in which these constructions are involved, it is advisable to remove such combustibles from

contact with the partition to prevent possible recurrence of fire. Partitions having incombustible framing

and incombustible facings not disrupted on the

unexposed side by the fire exposure remain as

barriers to the passage of flame and hot gases en masse under fire exposures considei-ably

longer than those corresponding to their fire- endurance period as determined according to the test specifications. The same is true to some extent for wood-stud partitions with

plaster facings on incombustible lath, although

after the facing on the fire-exposed side has

collapsed and wood supports are largely con- sumed, the other facing would have little stability.

These tests were designed to determine the

resistance to communication of fire through

the partition and were not concerned

with the degree to which the spread

of fire along the surface of the facings was facilitated or prevented, nor with the fuel contributed by the construction itself. It is readily seen that the various types present large

differences in these latter respects, which define

in part their general fire-retardant or fire- hazard properties. In the evolution of modern

building construction, the substitution of plaster on wood laths for wood interior finish

[46]
presented a decided improvement from the

fire-hazard staudijoiiit, and a resistance of K

hr to a tire of intensity comparable to that in the fm-nace test represents a considerabk^ gain

in this respect also. The difference between

this performance and that with combustible

finishes may appear minor, but actually it has

a very importaiit bearing on the hazard to life and property. The higher fire resistance shown

herein as attainable with ordinary constructions by the use of proper details, indicates

that further improvements can be obtained

without necessitating change to basically differ- ent constructions or construction methods.

VII. APPENDIX A

STANDARD SPECIFICATIONS

FIRE TESTS OF BUILDING CONSTRUCTION AND MATERIALS

American Standard A. S. A. No. A2-1934

[Prepared by the Sectional Committee on Fire Tests of Materials and

Construction, under the joint sponsorship of the National Bureau of Standards, the A. S. A. Fire Protection Group and the American Society

for Testing Materials, functioning under the procedure of the American

Standards Association.] The performance of walls, columns, floors, and other

l)uilding members under fire exposure conditions is an

item of major importance in securing constructions which are safe and which are not a menace to neighboring structures nor to the pubhc. Recognition of this

is registered in the codes of many authorities, municipal

and other. It is important to secure balance of the many units in a single building, and of buildings of

like character and use in a community; and also to promote uniformity in requirements of various authorities thioughout the country. To do this it is necessaiy

that the fire-resistive properties of materials and as- semblies be measured and specified according to a common standard expressed in teims which are appli- cable ahke to a wide variety of materials, situations, and

conditions of exposure. Such a standi}.rd is found in the specifications which

follow. They prescribe a standard exposing fire of controlled extent and severity. Performance is defined as the period of resistance to standard exposure

elapsing before the first critical point in behavior is observed. Results are reported in units in which field exposures can be judged and expressed.

The specifications may be cited as the "Standard

Fire Test Specification" and the performance oi ex- posure shall be expressed as "2-hour," "6-hour,"

"J-^-hour," etc. When a factor of safety exceeding that inherent in the test conditions is desired, a proportional increase

should ])v made in the spectificd time-classification period.

Classifications of assemblies involving combustibles

in such kind or quantity or so contained as to burn

freely during the exiiosurc to the test firc^ or continue

flaming after the furnace is shut ofl" shall be designated

by the term "combustible" after the period assigned.

Scope.

1 (a). The test methods are applicable to assemblies

of masonry units and to composite assemblies of structural materials for buildings, including bearing and other

walls and partitions, columns, girders, beams and

slaljs, and composite slab and beam assembhes for

floors and roofs. They are also applicable to other

assemblies and structural units which constitute per- manent integral parts of a finished building.

(b). It is the intent that classifications shall register

performance during the period of exposure and shall not be construed as having determined suitability for use after fire exposure. CONTROL OF FIRE TESTS

Time-Temperature Curve.

2. The conduct of fire tests of materials and construction shall be controlled by the standard time-temperature curve shown in fig. 1. The points on the curve which determine its character are:

1,000° F (approximately 538° C) at 5 min.

1,300° F (approximately 704° C) at 10 min.

1,550° F (approximately 843° C)._. at 30 min.

1,700° F (approximately 927° C) __ at 1 hr.

1,850° F (1,010° C) at 2hr.

2,000° F (approximately 1,093° C) at 4 hr. 2,300° F (1.200° C) at 8 hr. or over 2400

2200

TIME, HOURS. Figure 1.

Time-temperature curve.

[47]
Determination of Furnace Temperatures.

3 (a). The temperature fixed by the curve shall be deemed to be the average temperature obtained from

the readings of several thermocouples (not less than

three) systematically disposed and distributed to show

the temperature near all parts of the sample, the ther- mocouples being inclosed in sealed porcelain tubes

Yi in. in outside diameter and of J^-in. wall thickness. The exposed length of the porcelain tube and couple

in the furnace chamber shall be not less than 12 in. Other types of protecting tubes or pryometers may be

used that under test conditions give the same indications as the above standard within the limit of accuracy

that applies for furnace-temperature measurements. For greater difference of design and size the timetemperature curve followed shall be modified to give an exposure equal to that obtained by using the stand- ard pyrometer and curve above described.

(b) . The temperatures shall be read at intervals not

exceeding 5 min during the first hour, and thereafter the intervals may be increased to not more than 15 min.

(c) . The accuracy of the furnace control shall be such that the area under the time-temperature curve, obtained by averaging the results from the pyrometer

readings, is within 15 percent of the corresponding area under the standard time-temperature curve shown in

fig. 1 for fire tests of one hour or less duration; within

10 percent for those over one hour and not more than two hours; and within 5 percent for tests exceeding two hours in duration.

Determination of Temperatures of Unexposed Surfaces

of Floors, Walls and Partitions.

4 (a). Temperatures at unexposed surfaces shall be measured with thermocouples or thermometers ' placed

under flexible, oven-dry, felted asbestos pads 6 in. square, 0.4 in. in thickness, and weighing not less than

1.0 nor more than 1.4 lb per sq ft. The pads shall be

sufficiently soft so that, without breaking, they may be shaped to contact over the whole surface against which

they are placed. The wire leads of the thermocouple

or the stem of the thermometer shall have an immersion under the pad and be in contact with the unexposed surface for not less than in. The hot junction

of the thermocouple or the bulb of the thermometer shall be placed approximately under the center of the pad.

The outside diameter of protecting tubes of glass, clay, or

porcelain, and of thermometer stems, shall not be more

than Yit in. The pad shall be held firmly against the

surface, and shall fit closely about the thermocouples or thermometer stems. Thermometers shall be of the partial-immersion type, with a length of stem, between

the end of the bulb and the immersion mark, of 3 in. The wires for the thermocouple in the length covered by the pad shall not be heavier than No. 18 B&S gage

(0.04 in.) and shall be electrically insulated with heat- and moisture-resistant coatings.

1 Under certain conditions it may be unsafe or impracticable to use thermometers.

(b) . The temperature readings shall be taken at not

less than five points on the surface, one of which shall be approximately at the center, and four at approximately the centers of the quarter sections. If additional points are used they shall be symmetrically dis- posed about the center, with no location nearer than

iy2 times the thickness of the construction, or nearer than 12 in., to the edges. None shall be located opposite or on top of beams, girders, pilasters or other

structural members.

(c) . Temperature readings shall be taken at intervals not exceeding 15 min. until a reading exceeding 212° F. (100° C) has been obtained at any one point. Thereafter the readings may be taken more frequently at the

discretion of the testing body, but the intervals need

not be less than 5 min.

(d) . Where the Conditions of Acceptance place a

limitation on the rise of temperature of the unexposed

surface, the temperature end point of the fire endurance

period shall be determined by the average of the measurements taken at individual points; excepting

that if a temperature rise 30 percent in excess of the

specified limit occurs at any one of these points, the re- mainder shall be ignored and the fire endurance period

judged as ended. CLASSIFICATION AS DETERMINED BY TEST

5. Results shall be reported in accordance with the performance in the tests prescribed in these specifications. They shall be expressed in time periods of resistance, as for example 4-hour, }4-hour, etc.

TEST STRUCTURES

5 (a) . The test structure may be located at any place

where all the necessary facilities for properly conducting

the test are provided.

(b) . Entire freedom is left to each investigator in the

design of the test structure and the nature and use of

fuel, provided the test requirements are met.

TEST SAMPLES

7. The test sample shall be truly representative of the construction for which classification is desired as to materials, workmanship, and details such as dimensions

of parts, and shall be built under conditions representative of those obtaining as practically applied in building construction and operation. The physical properties

of the materials and/or ingredients used in the test sample shall be determined and recorded. CONDUCT OF FIRE TESTS

Fire Endurance Test.

8. The fire endurance test on the sample with its applied load, if any, shall be continued until failure occurs, or until it has withstood the test conditions for a

period equal to that herein specified in the Conditions

of Acceptance for the given type of construction.

[48]
Hose Stream Test.

9 (a). Where required by the Conditions of Acceptance, a duplicate sample shall be subjected to a fire exposure test for a period equal to one-half of that

indicated as the resistance period in the fire endurance

test, but not for more than one hour, immediately after which the sample shall be subjected to the impact,

erosion and cooling effects of a hose stream directed

first at the middle and then at all parts of the exposed

face, changes in direction being made slowly.

Exemption.

(b) . The hose stream test shall not be required in the

case of constructions having a resistance period, indi- cated in the fire endurance test, of one-half hour or

less. [*]

Optional Program.

(c) . The submittor may elect, with the advice and

consent of the testing body, to have the hose stream test made on the sample subjected to the fire endurance

test and immediately following the expiration of the

fire endurance test.

Hose Stream Equipment and Details.

(d) . The stream shall be delivered through 23'^-in. hose, discharging through a National Standard Playpipe

of corresponding size equipped with a l}^-in. discharge

tip of the standard taper smooth-bore pattern without

shoulder at the orifice. The water pressure and duration of application shall be as specified in table I. Table I.

Parts of structure

Floors and roofS-_

Walls and parti- tions

Resistance period

8 hours and over

4 hours and over if less than

8 hours

2 hours and over if less than 4 hours

1 hour and over if less than 2 hours

.Less than 1 hour

'8 hours and over

4 hours and over if less than 8 hours

2 hours and over if less than 4 hours

1 hour and over it less than 2 hours

.Less than 1 hour

"Water

pressure

at nozzle

lb per sq in.

Duration

of application, minutes

per 100 sq ft ex- posed area

52H

1

6

5

21/2

1

Nozzle Distance.

(e). The nozzle orifice shall be 20 ft from the center of the exposed surface of the test sample if the nozzle is so located that when directed at the center its axis is normal to the surface of the test sample. If otherwise

located its distance from the center shall be less than 20

ft by an amount equal to 1 ft for each 10 deg. of deviation from the normal.

[•According to revisions now in progress, constructions having fire en- durance of less than 1 hour will be exempted from the hose stream test.]

Time of Testing.

10. The material or construction shall not be tested

until a large proportion of its final strength has been

attained, and, if it contains free water, until the excess has been given off; this will usually require about 30

days' time under favorable drying conditions. Artificial drying at temperatures not injurious to the material

or construction to be tested may be used. TESTS OF BEARING WALLS AND PARTITIONS

Size of Sample,

11. The area exposed to fire shall be not less than 100

sq ft, with neither dimension less than 9 ft. The test specimen shall not be restrained on its vertical edges.

Loading.

12. During the fire endurance and fire and hose stream tests the construction shall be loaded in a manner

calculated to develop theoretically as nearly as practi- cable the working stresses contemplated by the design. Conditions of Acceptance.

13. The test shall not be regarded as successful unless the following conditions are met:

(a) . The wall or partition shall have sustained the applied load during the fire endurance test v/ithout passage of flame or gases hot enough to ignite cotton

waste, for a period equal to that for which classification

is desired.

(b) . The wall or partition shall have sustained the applied load during the fire and hose stream test as

specified in Section 9, without passage of flame, of gases hot enough to ignite cotton waste, or of the hose stream, and after cooling but within 72 hr after its completion

shall sustain a total load equal to the dead load plus twice the superimposed load specified above.

(c) . The fire-stopping, if any, shall have functioned

to prevent passage of fire for a period equal to that for which classification is desired.

(d) . Transmission of heat through the wall or parti- tion during the fire endurance test shall not have been

such as to raise the temperature on its unexposed sur- face more than 250° F (139° C) above its initial temperature.TESTS OF NONBEARING WALLS AND

PARTITIONS

Size of Sample.

14. The area exposed to fire shall be not less than 100

sq ft with neither dimension less than 9 ft. The test specimen shall be restrained on all four edges. Conditions of Acceptance.

15. The test shall not be regarded as successful unless the following conditions are met:

(a) . The wall or partition shall have withstood the

fire endurance test without passage of flame or gases hot enough to ignite cotton waste for a period equal to that for which classification is desired.

(b) . The wall or partition shall have withstood the

fire and hose stream test as specified in Section 9, with-

[49]
out passage of flame, of gases hot enough to ignite cotton waste, or of the hose stream.

(c) . The fire-stopping, if any, shall have functioned

to prevent passage of fire for a period equal to that for which classification is desired.

(d) . Transmission of heat through the wall or parti- tion during the fire endurance test shall not have been

such as to raise the temperature on its unexposed sur- face more than 250° F (139° C) above its initial temperature. TESTS OF COLUMNS

Size of Sample.

16. The length of the column exposed to fire shall, when practicable, approximate the maximum clear length contemplated by the design, and for building

columns shall not be less than 9 ft. The contemplated

details of connections, and their protection, if any, shall be applied according to the methods of acceptable field practice.

Loading.

17(a). During the fire endurance test the column

shall be exposed to fire on all sides and shall be loaded

in a manner calculated to develop theoretically as nearly as practicable the working stresses contemplated

by the design. Provision shall be made for transmitting

the load to the exposed portion of the column without

unduly increasing the effective cohunn length.

(b). If the submitter and the testing body jointly so

decide, the column may be subjected to 1% times its designed working load before the fire endurance test is undertaken. The fact that such a test has been made

shall not be construed as having had a deleterious effect on the fire endurance test performance.

Condition of Acceptance.

18. The test shall net be regarded as successful unless the column shall have sustained the applied load during

the fire endurance test for a period equal to that for which classification is desired.

TESTS OF FLOORS AND ROOFS

(The following contemplates application of fire ex- posure to the underside of constructions, and omission

from the upper surface of all units which are not essential to the constructions. Specifications and test pro- cedure with fire applied to the upper side have not been

developed.)

Size of Sample.

19. The area exposed to fire shall be not less than 180

sq ft with neither dimension less than 12 ft. Beams or

girders if a part of the construction under test shall lie within the combustion chamber and have a clearance

of not less than 8 in. from its walls. Loading.

20. During the fire endurance and fire and fire stream

tests the construction shall be loaded in a manner cal- culated to develop theoretically as nearly as practicable

the working stresses in each member contemplated by

the design. Conditions of Acceptance.

21. The test shall not be regarded as successful unless the following conditions are met:

(a) . The construction shall have sustained the applied load during the fire endurance test without passage of flame or gases hot enough to ignite cotton waste, for a period equal to that for which classification is desired.

(b) . The construction shall have sustained the applied load during the fire and hose stream test as specified

in Section 9, without passage of flame, of gases hot enough to ignite cotton waste, or of the hose stream, and after cooling but within 72 hr after its completion

shall sustain a total load equal to the dead load plus twice the superimposed load specified above.

(c) . Transmission of heat through the construction during the fire endru'ance test shall not have been such as

to raise the temperature on its unexposed surface more

than 250° F (139° C) above its initial temperature.

TESTS OF FINISH FOR COMBUSTIBLE FRAMING OR FACINGS OF WALLS, PARTITIONS,

AND CEILINGS

Character of Sample.

22. The test panel shall be a wall, partition, or floor.

(a) . Test panels carrying interior wall and partition

finish shall be finished on both faces with the finish which is the subject of the test; excepting that with

the advice or consent of the testing body this provision may be waived with respect to panels of solid construction.

(b) . Test panels carrying exterior wall finish on the exposed face shall be finished on the unexposed face with an interior wall finish judged by the testing body

to be suitable for purposes of the test; excepting that with the advice or consent of the testing body this provision may be waived with respect to panels of solid construction.

(c) . Test panels carrying ceiling finish shall be finished on the upper face with a flooring judged by the testing

body to be suitable for purposes of the test; excepting

that with the advice or consent of the testing body this provision may be waived with respect to panels of solid construction. Size of Sam.ple.

23. The area exposed to fire shall be for tests of wall and partition finish, not less than 100 sq ft, with neither dimension less than 9 ft; for tests of ceiling finish, not less than 180 sq ft, with neither dimension less than 12 ft. Conditions of Acceptance.

24. The test shall not be regarded as successful unless the following conditions are met:

(a) . The finish shall have withstood the fire endur- ance test, without passage of flame or of gases hot enough to ignite the materials protected, for a period

equal to that for which classification is desired.

(b) . The finish shall have withstood the fire and hose stream test as prescribed respectively for floors, walls,

[ 50 ]
and partitions as specified in Section 9, without passage

of flame, of gases hot enough to ignite the materials

protected, or of the hose stream.

(c). Transmission of heat through the finish during

the fire endurance test shall not have been such as to

raise the temperatures at its contact with the structural members of the test panel or elsewhere on its unexposed

surface more than 250° F (139° C) above the initial temperatures at these points.

VIII. APPENDIX B. SELECTED REFERENCES ON FIRE TESTS OF

WOOD-AND METAL-FRAMED PARTITIONS

British Fire Prevention Committee Reports, The

National Fire Brigades Association, 8 Waterloo Place,

Pall Mall, London, S. W., England.

Red Books Series: No. 22. Wood lath and plaster partition and the same with brick nogging (1899). No. 27. Match boarded partition with mineral wool

(1899). No. 44. Plaster on wire lath with burnt clay coverings at intersections of wires (1899). No. 47. Match boarded partition with chickenwire

and mineral wool (slag wool) (1900). Nos. 53 and 58. Steel studs with Ferroinclave and

plaster (1901). No. 63. Steel studs with twisted flat wire lath and

plaster (1901). No. 187. Pulp board partition one inch thick (1913). No. 192. Pulp board partition two inches thick

(1914). No. 193. Hollow partition of flame proofed wood

(1914). No. 195. Wood studs with wood lath and plaster on

one side also one partition with }^ in. matched boards on one side of studs plastered (1915).

Report of Tests of Partitions by Fire and Water,

Virgil D. Allen, Inspector of Buildings, Building

Department, Cleveland, Ohio (1912).

Reports of Underwriters' Laboratories, 207 East Ohio

Street, Chicago, Illinois as follows:

Retardmit Series: No. 1006. Report on Insura-Bcstwall Interior Wall,

Ceiling, and Partition Finish (July 20, 1918). No. 1355. Report on Interior Building Construction

Consisting of Metal Lath and Gypsum Plaster on Wood

Supports (August 10, 1922). No. 1828-2. Report on Insulite Plaster Base (December 16, 1926). No. 1828. Report on Fire Retardant Properties of Interior Wall and Partition Finish of Wood Lath and

Gypsum Plaster on Wood Studs (January 4, 1927). No. 1954. Report on Locklath Plaster Board (Plaster

Base) (April 13, 1927). No. 2258. Report on Ribbed Steeltex for Interior Plaster (Plaster Base) (May 1, 1930). No. 2393. Report on Thermax Board (Plaster Base)

(January 12, 1932). No. 2510. Report on Reynolds Ecod Fabric, Plain LTngalvanized, for Interior Plaster. Special Investigation No. 230. Report on Investigation of Fire Resistance of Wood Lath and Lime Plaster

Interior Finish (November 27, 1922).

Fire prevention and fire protection, Joseph K. Freitag, Fire Resisting Partitions, chap. 13, p. 381 (1922). Tests of Fireproof Partitions by the New York Building

Department, Eng. News, 46, No. 26, 482. Describes

fire tests on 16 partitions, 5 being of metal-framed

construction with metal-lath plaster base. Washington, December 10, 1940.

[51]

BUILDING MATERIALS AND STRUCTURES REPORTS

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

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

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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 10^ BMS4 Accelerated Aging of Fiber Building Boards 10^ BMS5 Structural Properties of Six Masonry Wall Constructions 15(4 BMS6 Survey of Roofing Materials in the Southeastern States 15fi BMS7 Water Permeability of Masonry Walls 10^ BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel 100 BMS9 Structural Properties of the Insulated Steel Construction Co.'s "Frameless-Steel"

Constructions for Walls, Partitions, Floors, and Roofs 100 BMSIO Structural Properties of One of the "Keystone Beam Steel Floor" Constructions Sponsored by the H. H. Robertson Co 10(6 BMSll Structural Properties of the Curren Fabrihome Corporation's "Fabrihome" Constructions for Walls and Partitions 100 BMS12 Structural Properties of "Steelox" Constructions for Walls, Partitions, Floors, and Roofs

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

the Wheeling Corrugating Co 100 BMS16 Structural Properties of a "Tilecrete" Floor Construction Sponsored by Tilecrete Floors, Inc 100 BMS17 Sound Insulation of Wall and Floor Constructions 100 BMS18 Structural Properties of "Pre-Fab" Constructions for Walls, Partitions, and Floors Sponsored by the Harnischfeger Corporation 100 BMS19 Preparation and Revision of Building Codes 150 BMS20 Structural Properties of "Twachtman" Constructions for Walls and Floors Sponsored by

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

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

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

Sponsored by the Nelson Cement Stone Co., Inc 100 BMS27 Structural Properties of "Bender Steel Home" Wall Construction Sponsored by The

Bender Body Co 100 BMS28 Backflow Prevention in Over-Rim Water Supplies 100 BMS29 Survey of Roofing Materials in the Northeastern States 100

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

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

Fir Plywood Association 10(4 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- 10<^ BMS33 Plastic Calking Materials 10^ BMS34 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 1 lO^i BMS35 Stability of Sheathing Papers as Determined by Accelerated Aging 10^ BMS36 Structural Properties of Wood-Frame Wall, Partition, Floor, and Roof Constructions

with "Red Stripe" Lath Sponsored by the Western Paper and Manufacturing Co.. 10^ BMS37 Structural Properties of "Pahsade Homes" Constructions for Walls, Partitions, and

Floors, Sponsored by Palisade Homes 100 BMS38 Structural Properties of Two "Dunstone" Wall Constructions Sponsored by the W. E. Dunn Manufacturing Co 100 BMS39 Structural Properties of a Wall Construction of "Pfeifer Units" Sponsored by the Wisconsin LTnits Co 100 BMS40 Structural Properties of a Wall Construction of "Knap Concrete Wall Units" Sponsored

hy Knap America, Inc 100 BMS41 Effect of Heating and Cooling on the Permeability of Masonry Walls 100 BMS42 Structural Properties of Wood-Frame Wall and Partition Constructions With "Celotex"

Irsulating Boards Sponsored by the Celotex Corporation 100 BMS43 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 2 100 BMS44 Surface Treatment of Steel Prior to Painting 100 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 100 BMS47 Structural Properties of Prefabricated Wood-Frame Constructions for Walls, Partitions,

and Floors Sponsored by American Houses, Inc 100 BMS48 Structural Properties of "Precision-Built" Frame Wall and Partition Constructions

Sponsored by the Homasote Co 100 BMS49 Metallic Roofing for Low-Cost House Construction 100 BMS50 Stability of Fiber Building Boards as Determined by Accelerated Aging 100 BMS51 Structural Properties of "Tilecrete Type A" Floor Construction Sponsored by the Tile- crete Corporation 100 BMS52 Effect of Ceiling Insulation Upon Summer Comfort 100 BMS53 Structural Properties of a Masonry Wall Construction of "Munlock Dry Wall Brick,"

Sponsored bv the Munlock Engineering Co 100 BMS54 Effect of Soot on the Rating of an Oil-Fired Heating Boiler 100 BMS55 Effects of Wetting and Drying on the Permeabihty of Masonry Walls 100 BMS56 A Survey of Humidities in Residences 100 BMS57 Roofing in the United States—Results of a Questionnaire 100 BMS58 Strength of Soft-Soldered Joints in Copper Tubing 100 BMS59 Properties of Adhesives for Floor Coverings 100 BMS60 Strength, Absorption, and Resistance to Laboratory Freezing and Thawing of Building

Bricks Produced in the United States 150 BMS61 Structural Properties of Two Nonreinforced Monolithic Concrete Wall Constructions. _ 100 BMS62 Structural Properties of a Precast Joist Concrete Floor Construction Sponsored by the Portland Cement Association 100 BMS63 Moisture Condensation in Building Walls 100 BMS64 Solar Heating of Various Surfaces 100 BMS65 Methods of Estimating Loads in Plumbing Svstems 100 BMS66 Plumbing Manual 200

BMSG7 Structural Properties of "Mu-Steel" Prefabricated Sheet-Steel Constructions for Walls,

Partitions, Floors, and Roofs Sponsored by Herman A. Mugler 150 BMS68 Performance Test of Floor Coverings for Use in Low-Cost Housing. Part 3 150 BMS69 Stability of Fiber Sheathing Boards as Determined by Accelerated Aging 100 BMS70 Asphalt-Prepared Roll Poofings and Shingles 1 150 BMS71 Fire Tests of Wood- and Metal-Framed Partitions 200