Stc Rating Of Concrete Walls

1 contains procedures for determining stc values of concrete masonry walls.

Stc rating of concrete walls.

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. 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. Insulation will noticeably improve the stc rating of an assembly. These tests have indicated a direct relationship between wall weight and the resulting stc heavier concrete masonry walls have higher stc ratings.

According to the standard stc can be determined by field or laboratory testing in accordance with standard test methods or by calculation. Sound transmission class stc is an integer rating of how well a building partition attenuates airborne sound in the usa it is widely used to rate interior partitions ceilings and floors doors windows and exterior wall configurations see astm international classification e413 and e90. In general the stl of a concrete masonry wall increases with increasing frequency of the sound. For example a thick concrete wall will block more sound than a thin gypsum 2x4 wall.

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. These wall assembly files are used for planning and estimation purposes for many ul wall types such as fire rated wall assemblies. Staggered or double stud walls are higher rated than single stud walls. Due to increased mass poured concrete and concrete blocks typically achieve higher stc values in the mid stc 40s to the mid stc 50s than equally thick framed walls.

However the additional weight added complexity of construction and poor thermal insulation tend to limit masonry wall partitions as a viable sound isolation solution in many. Many sound transmission loss tests have been per formed on various concrete masonry walls. When the mass of a barrier is doubled the isolation quality or stc rating increases by approximately 5 db which is clearly noticeable. Sound transmission class guidance introduction the noise guidebook.

Adding additional layers of drywall can improve the stc rating of an assembly. The standard requires a minimum laboratory stc rating of 50 for party walls and floor ceilings. Resilient channel can improve the stc rating of an assembly. Mass is commonly added to existing walls by adding additional layers of gypsum.

Usg provides resources here for our ul wall assemblies for seamless integration into any construction project. 5 or 6 points in laboratory stc ratings for essentially similar assemblies.