Q&X 3lLT6£UJI Of btSnCiaPQS

Library, N.W.

FEB 2 8 1356

UNITED STATES DEPARTMENT OF COMMERCE • Sinclair Weeks, Secretary NATIONAL BUREAU OF STANDARDS • A. V. Amin, Director

Reference book not to be

taker ^

urarv

Sound Insulation of Wall,

Floor, and Door Constructions

Richard V. Waterhouse

Supplement to Building Materials and Structures Report 144

Issued February 27, 1956

For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington 25. D. C.

Price 5 cents

Sound Insulation of Wall, Floor, and Door Constructions

Richard V. Waterhouse

The sound insulation figures are presented for 13 building structures that were measured

at the National Bureau of Standards in the period March 1954 to June 1955. The details are also given of a change in the method of measuring impact sound insulation.

1. Introduction

Building Materials and Structures Report 144, 1 issued February 25, 1955, included the results of sound insulation measurements made at the

National Bureau of Standards before March 1954.

This supplement includes the results of sound

insulation measurements made on 13 building constructions in the period March 1954 to June 1955.

It also includes details of a change in the method

of measuring impact sound insulation.

The test panels measured 5}i by 7 ft except for the door, which was 2% by 7 ft. The measurements

were made in accordance with the “Tentative

Recommended Practice for Laboratory Measurement of Airborne Sound Transmission Loss of

Building Floors and Walls,” Number E 90-50T,

of the American Society for Testing Materials.

Further details of the measuring technique are given on p. 8 of the publication BMS144 referred

to above. Most of the measurements cited here were performed by Howard S. Bowman and Henry

J. Leinbach Jr., of the Sound Section.

Differences of one or two db in the average

transmission loss of panels are not generally of

practical significance, as the human ear can

hardly detect such changes. Average trans- mission loss results are generally repeatable

within ± 1 db for any particular panel and within

±2 db for nominally identical constructions.

Estimates of the absolute accuracy of sound

transmission loss data are difficult to make; ex- perimental conditions necessarily depart some- what from the ideal conditions assumed in the

theory, and it is not easy to judge how much such

departures affect the results. However, we esti- mate that even in extreme cases the measured

average transmission loss figure would be within

±5 db of the true figure.

1 For sale by the Superintendent of Documents, U. S. Government Printing

Office, Washington 25, D. C., price 40 cents.

2. Impact Noise Measurement

The impact noise levels given in the results for the floor panels 711 and 712 give a measure of the

relative insulation of the panels to impact noises

(as opposed to airborne noises), and are obtained

as follows: When a standard tapping machine is operating on the test panel, the sound pressure level is measured in the room below the panel in octave

bands over the frequency range 125 to 4,000 cps. The sound level in each octave band is corrected

to a standard room absorption of 10 square meters,

the room absorption at the various frequencies

being known. From these corrected levels the

total corrected sound pressure is computed, and

this is called the impact noise level. The correction

procedure follows a proposed international standard, see Acoustics Group Symposium, p. 36, The

Physical Society, London (1949).

The tapping machine used in the measurements

has five metal hammers, each weighing 0.S4 lb, which fall a distance of 2.7 in. onto the test panel.

The hitting surface of each hammer is flat and

circular, with a diameter of 1 inch. The hammers are spaced about 3 in. on centers, and the

machine gives one tap every Jeth second.

The impact noise level used here supersedes the

tapping loss used previously as a measure of impact noise insulation, for example in BMS Report

144. The impact noise level is considered more

architecturally significant than the tapping loss since the latter depends on a quantity which is largely irrelevant, namely the sound-pressure level

in the room containing the tapping machine. It

is the sound level to be expected in the room below

the impact which is important when a floor-ceiling structure is being chosen.

The differences in the methods of measuring

the impact noise level and the tapping loss are such that the conversion of numerical values

from one to the other is not feasible.

1
Panel Descriptions

Panel 616.

Panel 237. Panel 238.

Panel 313.

Panel 317.

Panel 314.

Panel 318.

3- by 30- by 84-in. wooden door, of special soundproof construction; sponge-rubber gasket around sides and

top, approximately Yi-in. square cross-section, chamfered on hinge side; and a sponge-rubber drop closure at bottom of door.

Staggered 2- by 4-in. wood studs, each set 16 in. on centers and spaced 8 in. on centers with in. offset from the other set. On each side 3/s-in. plain gypsum lath and in. of gypsum vermiculite plaster. Same as panel 237 except airspace filled with vermiculite fill. Density of fill was 6.3 Ib/ft 3 or 1.8 lb/ft 2 of panel

area.

^V/////c

PANEL 313/317

3- by 12- by 30-in. hollow gypsum blocks. On one side Yi-in. sanded gypsum plaster; on other side resilient

clips, spaced 18 in. on centers vertically and 16 in. on centers horizontally , held vertical %-in. metal channel 16 in. on centers, expanded metal lath and % in. of sanded gypsum plaster. Same as panel 313 except 4- by 12- by 30-in. gypsum blocks were used.

3- by 12- by 30-in. hollow gypsum blocks. On one side Y>-in. sanded gypsum plaster; on other side resilient

clips, stapled 16 in. on centers horizontally and vertically, held 3/s-in. gypsum lath and }2 in. of sanded gyp- sum plaster. Same as panel 314 except 4- by 12- by 30-in. gypsum blocks were used.

2
Table 1 . Sound Transmission Loss and Impact Noise Levels of Some Building Structures

Panel

number

Transmission loss in decibels for various frequencies (cycles per second)

Weight

lb/ft 2 Impact

noise

level, a db

125 175 250 350 500 700 1,000 2,000 4,000

Average

1 25 to 4,000

DOOR

616 31 27 32 30 33 31 29 37 41 32

WALLS

Hollow Gypsum Tile

313 38 40 37 40 44 48 51 56 59 46 27

317 45 44 44 47 50 53 55 56 59 50 31

314 42 41 43 46 48 51 53 56 60 49 24

318 43 41 42 46 52 52 56 55 61 50 26

a See definition in text.
Panel 315. L H •.

Panel 316. m

Panel 319.

Panel 438.

Panel 711.

Panel 712.

Panel Descriptions—Continued

8- by 12- by 30-in. hollow gypsum blocks. On one side / in. of sanded gypsum plaster; on other side resilient clips (same as clips of panels 313, and 317 above) stapled 24 in. on centers horizontally , 28 in. on centers verti- cally, held /-in. horizontal metal channels and /-in. long-length gypsum lath wire-tied to the channels, and

/ in. of sanded gypsum plaster.

3- by 12- by 30-in. hollow gypsum blocks. On one side / in. of sanded gypsum plaster; on other side slotted

u resilient metal runners, placed horizontally 25 in. on centers, /-in. long-length gypsum lath wire-tied to the runners, / in. of sanded gypsum plaster. Same as panel 816 except 4- by 12- by 30-in. gypsum blocks were used.

r

PANEL 438

2/- by /-in. steel trusses used as studs 16 in. on centers. On each side resilient clips held /s-in. gypsum lath and / in. of gypsum vermiculite plaster; edges of lath held by other clips.

2- by 10-in. wood joists 16 in. on centers, cross braces with 1- by 3-in. wooden bridging strips bisecting length

of panel. On ceiling side /-in. gypsum wall-board, joints filled and taped; on floor side /-in. subflooring, rosin paper, and floating floor consisting of /- by 2-in. fiberboard 16 in. on centers, trapezoidal sleepers (1 )

in. wide at top, 2 in. at bottom, 1/ in. thick) 16 in. on centers, 2 /z 2-in. oak flooring.

Same as panel 711 except airspace in floating floor filled with vermiculite fill. Density of fill was 7.8 lb/ft 3 or 1.2

lbIft 2 of panel area. 4
Table 1 . Sound Transmission Loss and Impact Noise Levels of Some Building Structures—Continued

Transmission loss in decibels for various frequencies (cycles per second)

Impact

noise

level,* db

Panel number

125 175 250 350 500 700 1,000 2,000 4,000

Average

125 to 4,000

Weight

lb /ft 2

WALLS—Continued

Hollow Gypsum Tile—Continued

Steel Studs

FLOORS

711 30 20 29 30 37 40 42 50 56 37

712 24 21 30 33 40 41 46 52 58 3S

a See definition in text.

U S. GOVERNMENT PRINTING OFFICE: 1*5$

DEC 2 91958

UNITED STATES DEPARTMENT OF COMMERCE • Sinclair Weeks, Secretary NATIONAL BUREAU OF STANDARDS • A. V. Astin, Director

fo J/ id A

Sound Insulation of Wall,

Floor, and Door Constructions

Richard V. Waterhouse, Raymond D. Berendt, and

Richard K. Cook

2d Supplement to Building Materials and Structures Report 144

Issued December 1, 1958

For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington 25, D. C. Price 10 cents
The Library of Congress has cataloged this publication as follows

U. S. National Bureau of Standards.

Sound insulation of wall and floor constructions, prepared

by the staff of the Sound Section. Washington, U. S. Govt.

Print. Off., 1955.

iv, 66 p. illus., diagrs., tables. 26 cm. ( Its Building materials and structures report 144)

“Supersedes BMS17 and its Supplements 1 and 2.” Sound insulation of wall, floor, and door constructions

t by] Richard V. Waterhouse, Supplement to Building materials and structures report 114. Washington, U. S. Govt,

Print. Off., 1956.

5 p. diagrs., tables. 26 cm. TA410.U48 no. 144 Suppl. a

(Continued on next card)

58-60083

U. S. National Bureau of Standards. Sound insulation of

wall and floor constructions ... 1955. (Card 2)

Sound insulation of wall, floor, and door constructions

[byj Richard V. Waterhouse, Raymond D. Berendt, and

Richard Iv. Cook. 2d supplement to Building materials and

structures report 144. Washington, U. S. Govt, Print. Off., 1958.

13 p. diagrs., tables. 26 cm.

TA410.U4S no. 144 Suppl. b

1. Soundproofing. i. Waterhouse, Richard V. ii. Title. (Series)

TA410.U48 no. 144 *693.83 58-60083

Library of Congress
Sound Insulation of Wall, Floor, and Door Constructions

Richard V. Waterhouse, Raymond D. Berendt, and Richard K. Cook

Sound insulation data are presented for building structures measured at the National Bureau of Standards in the period July 1955 to December 1956. These figures constitute the second supplement to the data published in Building Materials and Structures Report 144. The accuracy of the figures is discussed. Details are also given of a new average figure, called the Energy Average, for the over-all sound insulation of a panel, and why it is preferable

to the Decibel Average, which it is designed to supersede.

1. Introduction

Building Materials and Structures Report 144, 1 issued in February 1955, and its first supplement,

! issued in February 1956, included the results of

| sound insulation measurements made at the

Xational Bureau of Standards through June 1955.

This second supplement gives results for 28

; building constructions obtained in the period July

1955 through December 1957.

The test panels measured approximately 5% by

7 ft except for most of the doors, whose dimensions

; are given with the panel descriptions. The

measurements were made in accordance with the

American Standard Recommended Practice for

Laboratory Measurement of Air-Borne Sound

Transmission Loss of Building Floors and Walls,

Xumber Z24. 19-1957, except for the fact that the

: average sound transmission loss values given here

i are based on the 11 frequencies cited, and not only

| on the 9 given in Z24.19. Further details of the

measuring technique are given on page 8 of

BMS144 referred to above. The measurements

| cited here were made with the assistance of H. J.

I Leinbach, Jr., and J. W. Harris of the Sound

j Section.

A new feature of the results presented here is

! that sound transmission loss (STL) figures at the

i frequencies 1,500 and 3,000 cps are included for

: most of these panels and the corresponding

i averages include the values at these frequencies.

: The advantage of including STL values at these

two frequencies is that the frequency range 125

to 4,000 cps is then covered throughout at approximately equal intervals of y2 octave. Thus a

i curve of STL versus frequency for a given panel

can be drawn more accurately. Also, the averI ages derived from the values at the different fre- quencies are not unduly weighted towards the low

; end of the frequency range, as was the case before

the two new frequencies were added.

2. New Average Figure for the Sound

Insulation of a Panel

Another new feature of the results presented

here is the use of a new average, called an Energy

Average, for the over-all sound insulation of a

panel. Most people agree that it is better to use

several figures to cover the entire range of fre- quencies, but that a single figure for the sound

insulation is a practical necessity for the architect

and builder.

The problem of finding a representative single

figure for the sound insulation of a panel, based on the values at the different frequencies, is complicated by the fact that the insulation the panel

affords in practice depends on the spectrum of the

noise present ; also the sensitivit}' of the ear varies

with the frequency of the sound.

For this single figure the arithmetic average of

the decibel STL values at the different frequencies

has often been used in the past, but it is generally

agreed to be far from perfect.

The chief objection to the decibel average is that

it does not rank panels correctly as regards their

useful over-all sound insulation. This is a serious

objection. It can happen, and has happened,

that a construction with a high decibel average

has been used on a building job when a less ex- pensive construction, with a lower decibel average,

would have given as good over-all sound insulation.

For this reason, the decibel average has been

superseded by a more accurate index in most

countries that are concerned with the measurement

of sound insulation. 2 The reason the decibel average is defective is that when the decibel figures are averaged, the

> For sale by the Superintendent of Documents, U. S. Government

Printing Office, Washington 25, D. C., price 40 cents

J See Handbook of Noise Control, edited by C. M. Harris, publishe '. by

the McGraw-Hill Book Co., ch. 40.

472687—58 1
higher STL values get too strong a weighting.

This can be seen from the fact that the decibel

average of the STL figures for a hypothetical panel can become arbitrarily large if only one of the

STL figures is increased. This is a quite unrealistic. state of affairs, since increasing one STL

value corresponds to reducing the energy that

would be transmitted by a panel at that frequency,

and as this energy is reduced it should influence the

average less, and not become the controlling factor. The new method used here is to average the

energy ratios to which the decibel figures cor- respond, instead of the decibel figures themselves.

The average of the ratios is then converted back

into the decibel form. The averaging of ratios

in this way removes the arbitrary logarithmic

weighting of the decibel average. The result is called an Energy Average, as opposed to a decibel average. It can also be

called an average noise reduction since it is equal

to the decibel reduction in level suffered by

randomly incident white-noise of equal energy per

octave in passing through the panel. The noise

considered here is of equal energy per octave

because the frequency bands used in the STL

measurements under discussion are evenly spaced on an octave scale, e. g., at p

or % octave intervals,

and each band is given equal weight in the average.

Thus the Energy Average has a clear and definite

physical interpretation.

It is recommended that when a single figure is used for comparing the over-all sound insulation

of two panels, the Energy Average should be used

rather than the decibel average. In some cases

this will reverse the rank ordering of two panels.

For example, in table 3, page 9, panel 239 has a higher decibel average, but a lower Energy Average

than panel 243 ; here panel 243 would give better

over-all sound insulation.

In table 2, page 3 of this Supplement, are given the Energy Averages for the panels listed in BMS144, excepting panels tested before 1932;

for the latter, the available data were insufficient

for useful average values to be obtained. When

STL values at 1,500 and 3,000 cps only were

lacking, these were interpolated.

Table 1 shows how the Energy Average is obtained, and compares it to the decibel average

for a panel whose STL figures increase 5 db per

octave. This behavior is typical of many panels.

A further discussion of the Energy Average is given in the Journal of the Acoustical Society of America, vol. 29, p. 544 (1957); in the latter paper

the Energy Average is referred to as the Linear

Average.

1 Table 1 . Sample calculation of the Energy Average

Frequency STL Energy ratio

cps db 125 20. 0 1. 000 XIO-*

175 22. 5 0. 562 250 _ 25. 0 . 316

350 27. 5 . 178 500 30. 0 . 100 700 32. 5 . 056

i.OOi) 35. 0 . 032

1,500 37. 5 . 018

2,000 _ 40. 0 . 010

3,000 42. 5 . 006

4,000 45. 0 . 003

Total _ _ 357. 5 2. 281X10-2 Decibel average 32. 5 db

Energy Average 26. 8 db

3. Accuracy of Results

Differences of 1 or 2 db in the Energy Averages

of panels are not generally of practical significance,

[ as the human ear can hardly detect such changes.

Our measurements of the Energy Average are | generally repeatable within ± 1 db for any particu- , lar panel and within ± 2 db for nominally identical i constructions. ! 1 Estimates of the absolute accuracy of sound

transmission loss data are difficult to make; ex- , perimental conditions necessarily depart some- i what from the ideal conditions assumed in the,

theory, and it is not easy to judge how much these

j departures affect the results. The chief sources

of error are (1) the imperfect diffusion of the

sound fields used in the test measurement, (2) the

arbitrary nature of the edge condition of the test panel, and (3) the limited size of the test panel.

However, we estimate that in most cases the;; measured Energy Average STL figure would be! within ±5 db of the true figure for a large panel,

i. e., a panel large enough for its lowest vibrational;

mode to be well below the lowest measuring

frequency.

With regard to the accuracy of the measured;

STL values at the various frequencies, the values) at 125, 175, and 250 cps are less accurate than,, r those at the other frequencies, since the rooms on i; either side of the test panel are too small in volume

to give a sufficiently diffuse sound field at lowi; : frequencies.

The above comments on repeatability and ac^ ;; curacy refer only to results obtained at the

' National Bureau of Standards. These results . may differ by several decibels from those obtained - on nominally identical panels at other laboratories.

2
Table 2. Energy Averages for some of the panels listed in EMAlf/,

Panel number Energy

average Decibel

average Panel number Energyaverage Decibel

average Panel number Energyaverage

Decibel

average Panel number Energy

average

Decibel average

136A

db 43

db 53 179 Adb24db 31 306

db38db 39 1 503db 35

db 38

136B 51 61 179B 24 35 307- 50 53 504_ 34 37

137 41 53 179C 25 35 308- 48 49 505- 35 38 137A 46 54 179D 23 34 309 38 40 506 36 39 137B 37 55 180 A 30 38 ; 310- 41 46 507 36 40

144 41 46 180B 40 50 311_ 19 20 508- . .. 39 42

145 40 45 180C 42 50 312 41 44 509 _ _ 43 47

146 32 35 180D 43 50 313 42 46 510 31 36 147A 38 42 180E 38 46 314. - 46 49 511 37 40 147B 41 47 180F 38 49 315 46 48 512 _ 38 40

14S 35 41 181 28 28 316 44 47 513 _ 40 42 149 41 48 182 28 30 317 48 50 514- 41 42 150 49 52 201 32 38 318- 47 50 515 40 41 151 39 50 °02 30 35 319- - 45 48 5 1

34 37

152 44 51 203 27 33 401 29 41 517 33 35

153 40 47 204_

30 37 402 37 42 518 35 39

154 38 40 205_ _ 34 41 403 31 39 519 31 34

155 38 41 206_ _ 24 32 ! 404 31 38 520 40 41 156 47 54 207- 25 33 405 - - 33 39 521 35 37 48 55 208 - 26 28 | 406 36 40 522 35 37

158- 47 55 i 209 35 40 407 36 41 523-- 37 39

159 32 33 210 19 30 408 37 42 ! 524 36 38

160A 53 55 211 21 24 409 - - - 37 42 525 32 33 160B 52 55 212 35 40 410-

37 43 ! 526-. 28 33 160C 51 54 213 48 51 411 37 43 ! 527 - 36 38

160D 49 53 214_ 21 26 412 42 47 528 29 30 160E 49 53 215. - 44 46 413 35 42 601 26 30 160F 48 51 216. _ 27 35 i 414 44 46 I 602 31 33 160G 48 51 217- 30 37 ! 415- 36 42 603 34 36 160H 47 48 218- - 31 39 1 416 42 44 604 35 36

1601 44 46 219 34 43 417 38 44 605 28 30

161 36 38 220 49 52 418. 45 47 j 606 23 24 162 34 A9 221 40 46 419 40 45 607 33 38

163 28 36 222 _ _ 51 54 420. - 50 52 , 612- _ 34 35

164 35 44 223 49 52 421 49 52 613 38 40

165 34 39 224 28 35 422 49 52 616 31 32

166A - 33 37 225 32 38 423 45 51 701 32 45 166B 36 38 226 34 40 424 42 46 702 37 50

167 49 52 227 _ 34 40 425 51 52 703 35 45

168 53 55 228 34 39 426 45 47 704 34 47

170 33 36 229 37 40 427 48 51 705 51 5 171

35 38 929 33 34 428 38 41 706 52 54 171B 32 35 233_ _ 39 40 429 54 55 1 707. - 31 40

171C' 31 36 234- 29 34 430 42 47 708- - 32 42

172 34 39 235. _ 42 43 431 40 44

44

709- - 46 49

173 A 36 37 236 43 45 433 41 710 - 48 51 173B 32 35 237 39 40 434 39 42 711- - 29 37 173C 10 11 238 42 47 435 34 39 712 . 29 38

174 31 35 301 38 42 436 39 43 801 - - 41 43

175 49 50 302 36 41 437- . 34 39 802 46 49

176 46 48 303 36 38 438 32 36 SOS 44 4S

177 28 36 304 38 39 501- . 32 34 S04 40 47

178 42 46 305 42 43 502 32 38 S05 44 51
Panel 617. Panel 618.

PANEL 617. Bottom closure of door.

2%-in. by 3-ft by 7-ft solid wooden door, 2 drop felts built into bottom; two tubular soft rubber gaskets mounted

on door jamb gave a double seal at top and sides. Seals similar to those of panel 617; 2}i-in. by S-ft by 7-ft sound-insulating wooden door consisting of a 25%- by 705/i-in. panel set centrally in both 8- by 7-ft faces; panels separated from outer frame by }i-in. rubber, as shown in drawing for panel 624.

Panel 624.

Panel 639.

3-in. by 7-ft by 3-ft sound-insulating door of construction similar to that in panel 618; screwed onto the jamb

at top and both sides were wooden strips to which were glued and lap-jointed a soft rubber gasket with a cor- rugated front edge. Sponge-rubber drop closure at bottom. 2%-in. by 3-ft by 7-ft sound-insulating wooden door of double construction: 2 interlocking frames separated by

felt sheet; door hung in split frame with felt insert; seals similar to those of panel 617 except 2 drop-felts were

replaced by a double tubular rubber gasket which closed onto a tapered wooden threshold.

I

Panel 640. Panel 641. Panel 642.Door same as in panel 68.9; seals same as in panel 617.

4-in. by 3-ft by 7-ft sound-insulating wooden door; construction and seals similar to those of panel 640. Same as panel 641 except the door was rigidly plastered into the jamb on both sides.

4
Table 3. Sound Transmission Loss of Some Building Structures

Transmission loss (in decibels) at frequencies (cycles per second) Panel number

125 175 250 350 500 700 ' 1,000 1,500 2,000 3,000 4,000 Decibel average

125 to 4,000

Energy I average [ 125 to 4,000 *

Weight

lb/ft

DOORS

617.

618.

624.

639.

640_

641.

642_

28

27

28

31

3434

39

31

32

27

33

22

31

28

36

27

35

32 | 34

30 | 35

34

29

38

36

30

3237

3537

41

30

3640

38

34

32 32

39 43

45 I 47

28

32

37

36

33

42

50

39

36

45

54

34

39

42

44

42

5156

32

34

47

43

48

4253

5S

38

53

62

29

33

36

37

35

424S

1 See definition and discussion of this term in the text.

- Energy Average of sound transmission loss (STL) figures at 11 frequencies; STL figures at 1,500 and 3,000 cps wore interpolated.

b 28

b 32

! b 35

34

I

33

38

43

5. 6

6. 8

7. 3

7. 3

6. 6

12. 3

12. 3
PANEL 645. Panel 645. Jfl/i-in. by 2-ft 6-in. by 6-ft 6-in. sound-insulating door, covered with unperforated sheet metal on both sides, mounted in metal frame: door and frame both flanged, with }i-in. thick sponge-rubber gaskets at top and sides': seal at the bottom of the door provided by a %,-in. rubber strip and door flange closing onto a metal threshold.

PANEL 643. Bottom closure of door. Panel 643. 5%-in. by f-ft 8-in. by 6-ft 2-in. metal-clad door, which closed, at top and sides against a 2- by 2-in. steel angle

lined with %-in. thick sponge-rubber; in addition a double rubber gasket provided a seal around all four edges

of the door. The bottom edge of the door also carried a rubber strip which closed against a half oval metal

threshold. The 4-in. internal airspace of door was filled with pieces of cork.

PANEL 644. anel 644. Metal-clad double door, 5%-in. by 6-ft 2-in. by f-ft 8-in. over-all; top, side, and bottom seals similar to those of panel 643 except at the bottom a sponge-rubber drop-closure replaced the two tubular gaskets. Where the 2

doors met, the vertical crack was covered by a flange projecting from 1 door; the flange and door-edge were lined with %-in. sponge-rubber; an extra seal where the doors met was given by a tubular rubber gasket Cork fill as m panel 643.

6
Table 3. Sound Transmission Loss of Some Building Structures—Continued

Transmission loss (in decibels) at frequencies (cycles per second; Panel number

125 175 250 350 500 700 | 1,000 1,500 2,000 3,000 4,000 Decibel Energyaverage j average

125 to 4,000 125 to 4,000 »

1

Weight

lb/ft 2

DOORS—Continued

645- 33 30 31 28 31 31 33 38 38 42 42 34 32 13. 0

Refrigerator-Type Doors

643 41 35 40 43 49 50 52 54 57 60 64 50 43

644 36 32 41 44 48 52 53 54 56 58 61 40 40
Panel 646. 6-ft 4-in. by 4~ft 10-in. accordion type folding door consisting of 20 vertical panels forming 10 pleats on each

side, held on a folding metal frame; inside this outer case were 2 composition-board liners Y%-in. thick; rubber

sweep-strips covered the top and bottom edges of the door on both sides. The vertical edge was lined with a

Ytrin. round rubber bumper and closed onto 2 sponge-rubber strips. Panel 646A. Same as panel 646 except the two inner liners were removed, and the sweep strips at top and bottom on one : side only.

PANEL 240. Panel 239. 2- by 4-in. wood studs 16 in. on centers; fi-in. gypsum lath, Yi-in . sanded gypsum plaster. Panel^240. 2- by 4-in. wood studs 16 in. on centers; %-in. tapcred-edge gypsum wallboard; joints cemented and taped.

i

//

PANEL 241. Panel 241. 2- by 4-in. wood studs 16 in. on centers taped.

; 2 layers of Ys-in. tapered-edge gypsum wallboard; joints cemented and

\\\\\\\\\\\\\\\X\\\\\\\\\\\\ \ . vv\vv\vvv\

**

<

t. '/ 4^ /L i PANEL 242. Panel 242. 2- by 3-in. wood studs 16 in. on centers, staggered; Vi-in. tapered-edge gypsum wallboard; joints cemented and[

taped.

Panel 243. 2- by 3-in. wood studs 16 in. on centers, staggered; Yi-in. tapered-edge gypsum wallboard; joints cemented and'; taped.

PANEL 244. Panel 244. 2 by 3-in. wood studs 16 in. on centers, staggered; 2 layers of Yi-in. tapered-edge gypsum wallboard nailed on

j

joints cemented and taped. ' *
Table 3. Sound Transmission Loss of Some Building Structures—Continued

Transmission loss (in decibels) at frequencies (cycles per second)

Panel number Weight

Decibel Energy | lb/ft 2 125 175 250 350 500 700 , 1,000 1,501) 2,000 3,000 4,000 average average i 125 to 4,000 125 to 4,000 *

DOORS—Continued

Folding Doors

646, 20 18 18 19 24 29 31 31 32 32 35 26 22 2. 0

646A 18 16 15 15 16 20 25 26 27 29 32 22 19 1 . 1

WALLS

Wallboard or Plaster-Lath on Wood Studs

i 239 42 34 32 38 42 47 49 46 50 58 62 45 39 14. 2 240 30 22 31 30 37 39 44 43 39 45 52 37 31 7. 2

241 33 28 30 36 37 40 45 42 44 50 57 40 35 12. 9

242 36 31 36 40 40 46 47 50 52 41 45 42 38 6. 2

243 43 44 37 38 40 46 48 47 41 44 50 43 42

244 41 41 41 43 46 48 49 45 41 49 54 45 44 13. 4

9
its

Panel 245. 2- by 3-in. wood studs 16 in. on centers, staggered; 3/s-in. perforated gypsum lath, 16 by 48 in.; J4-m. sanded gypsum plaster.

PANEL 440. Panel 440. Five layers of %-in. cold-rolled steel channel, wire-tied together, formed core of panel. The center layer consisted

of 2 pieces of channel 2-iri. long placed vertically 40 in. apart and wire-tied between 2 horizontal lengths of \ channel. Vertical channels 16 in. on centers were wire-tied to the horizontal channels; 3/&-in. gypsum lath, 16-in. wide, was wire-tied to vertical channels; l/>-in. sanded gypsum plaster.

Panel 441. 3}{-in. steel trusses, 16 in. on centers; on each side spring clips 16 in. on centers fastened to trusses; )i-in. metal

rod wire-tied to clips; l i-in. metal lath wire-tied to metal rods; %-in. sanded gypsum plaster. Same as panel

429 in BMS144, p. 50.

PANEL 250. Panel 250. 23- by 23- by Pi-in. hollow plastic panels, 3/% 2-in. thick skin; set into 2 in. aluminum FI beams; each face of each \ panel contained 800 horn-shaped depressions.

Panel i 13. 2- by 10-in. joists, 16 in. on centers; 1- by 6-in. subfloor, tongue and groove; 2 %2

- by 4-in. finish floor, fir; ceiling, side 2 layers of %-m. gypsum wallboard; joints cemented and taped.

I anel 714. Same as panel 713 except on ceiling side 3/%-in. perforated gypsum lath; Yi-in . sanded gypsum plaster.

PANEL 245.

10
i Table 3. Sound Transmission Loss of Some Building Structures- Continued

Transmission loss (in decibels) at frequencies (cycles per second) Panel number

125 175 250 350 500 700 1,000 1,500 2,000 3,000 4,000 Decibel

average

125 to 4,000

Energy

average

125 to 4,000 >*

Weight

Ib/ft 2

WALLS—Continued

Wallboard or Plaster-Lath on Wood Studs—Continued

245 48 48 46 47 48 47 48 43 48 55 59 49 47 15. 6

Gypsum Lath Wire-Tied to Steel Studs

J 49 48 49 51 53 56 59 53 58 63 63 55 52

FLOORS

Wood Joists

713 28 27 28 34 32 36 44 48 52 51 55 40 32

714 33 32 26 32 33 39 41 45 48 56 62 41 33

11
4 V

~

*3 4 4 5 4 4 4

4~

Panel 806. 2-m. concrete on %-in. rib lath: 6- by 6-in. wire mesh embedded in concrete; 12-in. open-web metal joists, 24-in. on centers; nailing channels wire-tied to lower side of joists; %-in. wallboard; joints cemented arid taped.

PANEL 627. Panel 627. Section of outer part of aircraft fuselage, aluminum alloy; outer skin 0.0.90 in. thick. The panel included some

stiffening members not shown in drawing.

Panel 628. Section of outer part of aircraft fuselage, aluminum alloy; outer skin 0.090-in. thick. The panel included some

stiffening members not shown in drawing.

PANEL 629. Panel 629. Section of outer part of aircraft fuselage, aluminum alloy; outer skin 0.080-in. thick; inner layer 0.063-in.

thick. The panel included some metal stiffening members not shown in drawing.

12
Table 3. Sound Transmission Loss of Soma Building Structures- -Continued

Transmission loss (in decibels) at frequencies (cycles per second) Panel number

125 175 250 350 500 700 1,000 1,500 1 2,000 3,000 4,000

1

! 1 !

Decibel average

125 to 4,000

Energy

average

125 to 4,000 '

Weight

Ib/ft 2

806-

FLOORS—Continued

Concrete Slab on Metal Studs

40 38 40 43 46 48 51 54 53 51 54 47 44 34. 2

627.

628-

629.

PART OF AIRCRAFT FUSELAGE

22 16 14 18 24 23 23

23 17 : is

23 17 13

20 19 18 23

20 25 22 24

23

24

29

23

26

21

21

b 20 2. 6

b 20 2. 6

22 b 20

b Energy Average of sound transmission loss (STL) figures at 11 frequencies; STL figures at 1,500 and 3,000 cps were interpolated. Washington, April 15, 195S.

13

U. S. GOVERNMENT PRINTING OPFICIi 1*3*