ASTM C919-2019 pdf free download
ASTM C919-2019 pdf free download.Standard Practice for Use of Sealants in Acoustical Applications
1. Scope
1.1 This practice provides information for the use of seal- ants to reduce sound transmission characteristics of interior walls, ceilings, and floors by proper application of sealants to joints, voids, and penetrations normally found in building construction, which are commonly referred to as “flanking paths.” 1.2 The committee with jurisdiction over this standard is not aware of any comparable standards published by other orga- nizations. 1.3 This standard does not purport to address fire stopping or safing requirements for joints, voids, and penetrations through fire-rated wall, ceiling, and floor assemblies. Addi- tional requirements may be necessary for fire-rated assemblies to meet the applicable building code provisions. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Significance and Use
4.1 Walls, ceilings, and floors in building construction, especially those that are of lightweight construction, and that are designed to reduce or limit sound transmission, can have undesirable sound transmission characteristics if care is not taken to seal joints, voids, and penetrations that typically occur. Unsealed joints, voids, and penetrations will substantially increase the sound transmission characteristics of these types ofconstruction. By sealing them the transmission of sound can be substantially diminished by eliminating “flanking paths.”
5. Sound Transmission Requirements
5.1 The construction industry has adopted Sound Transmis- sion Class (STC) units, as defined in Terminology C634, to rate the sound transmission properties of walls, ceilings, and floors. The STC is determined in accordance with Classification E413. The test data are obtained in accordance with Test Methods E90 and E336. 5.2 Various building and other governmental adopted codes include requirements for sound transmission. 5.2.1 For example, the International Building Code (IBC), Section 1206.2, has requirements for the amount of sound that is allowed to be transmitted through common interior walls, partitions, and floor and ceiling assemblies between adjacent dwelling units or between dwelling units and adjacent public areas of a building, such as halls, corridors, stairs, or service areas. This Section also includes requirements for penetrations or openings in these assemblies, including piping and electrical devices, to be sealed, lined, insulated, or otherwise treated to maintain the required ratings. 5.2.2 Additionally, the department of Housing and Urban Development (HUD) has the following standard for STC limitations for various housing units: HUD Minimum Property Standards for Housing, Section 4910.1.
6. Why Seal Openings?
6.1 The sound transmission of a wall, ceiling, or floor, no matter how well built, can be substantially defeated by the presence of unsealed joints, voids, and penetrations. Fig. 1 illustrates examples of how sound travels through unsealed joints, voids, and penetrations in walls and how sealing them with liquid-applied sealants or precured sealants will minimize sound transmission. Other alternatives for sealing joints, voids, and penetrations include the use of adhesive backed tapes, films, membranes, or aerosol foam sealants. 6.2 The effect of unsealed joints, voids, and penetrations on the STC rating of partition walls is illustrated in Fig. 2. For the sample wall example, with an STC rating of 40 that has openings that total 9 cm 2 (1.4 in. 2 ) will have its STC reduced to 36, a 10 % difference. However, that small difference results in a change to the apparent loudness of sound transmission to that which is twice as loud.
