1、Designation: C 919 08Standard Practice forUse of Sealants in Acoustical Applications1This standard is issued under the fixed designation C 919; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in
2、parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice is a guide for the use of sealants to reducethe sound transmission characteristics of interior walls, ceil-ings, and floors by prop
3、er application of sealants to joints,voids, and penetrations normally found in building construc-tion.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and he
4、alth practices and determine the applica-bility of regulatory limitations prior to use.1.3 The committee with jurisdiction over this standard is notaware of any comparable standards published by other orga-nizations.2. Referenced Documents2.1 ASTM Standards:2C 570 Specification for Oil- and Resin-Ba
5、se Caulking Com-pound for Building Construction3C 634 Terminology Relating to Building and Environmen-tal AcousticsC 834 Specification for Latex SealantsC 920 Specification for Elastomeric Joint SealantsE90 Test Method for Laboratory Measurement of AirborneSound Transmission Loss of Building Partiti
6、ons and Ele-mentsE 336 Test Method for Measurement of Airborne SoundAttenuation between Rooms in BuildingsE 413 Classification for Rating Sound InsulationE 497 Practice for Installing Sound-Isolating LightweightPartitions32.2 DHUD Standards:4HUD Minimum Property Standards for One and Two FamilyHousi
7、ng, Section 4900.1HUD Minimum Property Standard for Multi Family Hous-ing, Section 4910.1HUD Minimum Property Standard for Care Type Housing,Section 4920.13. Significance and Use3.1 Construction utilizing lightweight walls and floors canhave undesirable sound transmission characteristics if care isn
8、ot taken to seal joints and voids that are common to this typeof construction. By sealing these penetrations the transmissionof sound can be diminished.4. Sound Transmission Class4.1 The construction industry has adopted Sound Transmis-sion Class (STC) units (defined in Definitions C 634) to ratethe
9、 sound barrier properties of walls, ceilings, and floors. TheSTC is determined in accordance with Classification E 413.The test data are obtained in accordance with Test MethodsE90orE336.NOTE 1For example, The Department of Housing and Urban Devel-opment (DHUD) has issued the following three standar
10、ds dealing with theSTC limitation in various housing units:HUD Minimum Property Standard for One and Two Family Housing,Section 4900.1;HUD Minimum Property Standard for Multi Family Housing, Section4910.1; andHUD Minimum Property Standard for Care Type Housing, Section4920.15. Need to Seal Openings5
11、.1 The effect of unsealed openings on the STC of partitionwalls is shown in Fig. 1. This chart also shows the improve-ment of the STC when openings are sealed. It should berecognized for slit openings that the STC values may bedifferent from the STC value for a hole opening.1This practice is under t
12、he jurisdiction of ASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of Subcommittee C24.10 onSpecifications, Guides and Practices.Current edition approved May 1, 2008. Published June 2008. Originallyapproved in 1979. Last previous edition approved in 2002 as C 919 02
13、.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from Superintendent of Documents, U.S.
14、 Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Fig. 2 shows examples of how sound travels throughopenings in walls and how sealing may serve to minimizesound transmission. Further
15、 examples may be found in PracticeE 497.6. Positioning of Sealants6.1 Fig. 3 illustrates placement of beads of sealant toimprove the STC from a value of 29 to a value of 53. Note thattwo properly placed beads are sufficient and sealing beyondthat point is unnecessary.7. Application Method of Gunnabl
16、e Sealant7.1 Fig. 4 shows typical sealant applications.8. Types of Sealant for Acoustical Improvement8.1 Preformed SealantsPreformed sealants include gas-keting, tapes, and preformed foams. Most of these materials areeffective only when the tolerances of the perimeter joints canbe accurately predict
17、ed and installed to those tolerances. Jointsizes vary widely and preformed sealants may have difficulty inmaintaining a proper seal at all points with the constantcompression that is necessary to effect a seal. Preformedsealants in the form of pads have proved to be effective forsealing electric, te
18、lephone, and television jack boxes.8.2 Gunnable SealantsThese sealants have the capacity ofconforming to the wide range of joint sizes encountered inmost construction. The following types are available:8.2.1 Skinning and Drying SealantsSkinning and dryingsealants such as asphalt- and oil-based caulk
19、ing compoundsperform satisfactorily initially but within a short period of timecould begin to shrink, harden, crack, and lose adhesion, therebylosing their effectiveness in providing a positive seal. Many ofthese sealants tend to stain the walls. Specification C 570references these sealant types.8.2
20、.2 Nondrying, Nonhardening, Nonskinning SealantsOfall the products evaluated to date, the nondrying, nonharden-ing, nonskinning types of sealant have proven to be the mosteffective in reducing sound transmission. By remaining indefi-nitely flexible as well as permanently adhesive, they canmaintain a
21、 positive airtight seal. These sealants normally arenonbleeding and will not stain walls. The nonskinning mate-rials should be used only in concealed areas. When used asexposed beads, they may stain through paint or pick up dirt.8.2.3 Nonoxidizing, Skinning SealantsSealants that skin,retain flexibil
22、ity, and maintain adhesion can be effective inreducing sound transmission. These sealants are preferred inexposed bead applications, as they readily accept paint andother finishes.8.2.4 Latex-Based SealantsLatex-based sealants that re-tain flexibility and maintain adhesion can be effective inreducin
23、g sound transmission. Specification C 834 referencesthese sealant types.8.2.5 Chemically Curing SealantsMany chemically cur-ing one- and two-part sealants are available. While normallyused for exterior seals, they can be effectively used for interiorsound reduction. Specification C 920 and Federal S
24、pecifica-tions TT-S-227E, TT-S-230C, and TT-S-1543A reference thesesealant types.FIG. 1 Effect of Unsealed Hole Openings on STC-Rated Test Wall,3.8by2.4m(12ft6in.by8ft)FIG. 2 Examples of Achieving an Effective Sound Barrier andMaintaining the Designed STC Value of Partition SystemsC9190829. Paintabi
25、lity of Exposed Beads of Sealants9.1 Sealant beads are usually painted if they are exposed.Because of the wide variety of types and brands of interiorpaint and the variety of types and brands of sealants, on-sitepaintability and stain tests are recommended.9.2 Paint applied before the sealant has cu
26、red may crackduring the curing process of the sealants. A reasonable sealantcure time should be allowed before painting. The sealantmanufacturer should be consulted regarding the recommendedcure time prior to painting. (Structural movement may causepaint to crack.)10. Keywords10.1 acoustical; sealan
27、ts; sound transmissionEdge DetailSTCValueCommentsuncaulked 29 the open-edge track gave the STC value of29 through direct leakagesingle bead at the perimeter of one baselayer49 this bead closed void but did not seal leak-age around the joint between the wallboardand tracktwo beads, one under each bas
28、e layer ofgypsum board53 the beads closed void and sealed leakagearound trackfour beads, one under each base and facelayer of gypsum board53 the void is closed; no leaks around track andwallboardNoteThe test partitions consisted of metal studs, 610 mm (24 in.) on center, with double layers of 13-mm
29、(0.5in.) wallboard screw-attached to each side. Soundattenuation blanket, 38 mm (1.5 in.), was placed in the void. The partition panels were erected, shimmed out 3 mm (0.125 in.) at the periphery: top, bottom, andedges.NoteData were obtained from the United States Gypsum Co. Round Lake Acoustical Re
30、search Facilities from a study conducted in accordance with Test MethodE 336.FIG. 3 Performance of a Partition System Sealed with Single or Multiple BeadsC919083ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this sta
31、ndard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be revi
32、ewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsib
33、le technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
34、nshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).(a)(b)(c)(d)FIG. 4 Typical Sealant ApplicationC919084
