Stc Rating For Concrete Walls

Sound transmission class guidance introduction the noise guidebook.

Stc rating for concrete walls.

Standard method for determining sound transmission ratings for masonry walls tms 0302 ref. These wall assembly files are used for planning and estimation purposes for many ul wall types such as fire rated wall assemblies. Fire resistance ratings with multi layer designs ul u415 oscillation tested to 1 million cycles to ensure structural performance. Mass is commonly added to existing walls by adding additional layers of gypsum.

Resilient channel can improve the stc rating of an assembly. Sound transmission class or stc is an integer rating of how well a building partition attenuates airborne sound in the us it is widely used to rate interior partitions ceilings floors doors windows and exterior wall configurations. 5 or 6 points in laboratory stc ratings for essentially similar assemblies. These tests have indicated a direct relationship between wall weight and the resulting stc heavier concrete masonry walls have higher stc ratings.

The standard requires a minimum laboratory stc rating of 50 for party walls and floor ceilings. Adding additional layers of drywall can improve the stc rating of an assembly. This is usu ally because there is a pronounced dip in the test curve and the stc rating is heavily influenced by a measurement in one fre quency band. Note that in the low frequency range important for music theaters traffic aircraft and most other real world noise sources the lower stc wall is literally 30 decibels better yet lower stc.

In general the stl of a concrete masonry wall increases with increasing frequency of the sound. Stc ratings for wall floor and window materials and assemblies 3 appendix a stc ratings a 1 walls a 1 exterior a 1 interior a 9 wooden studs a 9 metal studs a 14 floors a 16 wood a 16 concrete a 21 windows a 24 doors a 27 exterior a 27 interior a 29 appendix b references b 1. Area separation wall systems area separation wall submittal sheet sa925 wb2129 sheetrock shaft wall systems tested systems achieve up to 58 stc have achieved up to 4 hr. Staggered or double stud walls are higher rated than single stud walls.

According to the standard stc can be determined by field or laboratory testing in accordance with standard test methods or by calculation. Many sound transmission loss tests have been per formed on various concrete masonry walls. One has an stc 47 4 solid concrete the other an stc 48 steel stud wall. When the mass of a barrier is doubled the isolation quality or stc rating increases by approximately 5 db which is clearly noticeable.

Usg provides resources here for our ul wall assemblies for seamless integration into any construction project. For example a thick concrete wall will block more sound than a thin gypsum 2x4 wall. We see two walls.