Stc Ratings For Concrete Walls

If your wall graph is closest to a standard stc 35 curve your wall is said to have an stc rating of 35.

Stc ratings for concrete walls.

The estimate could easily be off by as much as 4 db. Tested systems achieve up to 58 stc have achieved up to 4 hr. Mass is commonly added to existing walls by adding additional layers of gypsum. The magenta line in that graph is the standard reference stc contour.

For example a thick concrete wall will block more sound than a thin gypsum 2x4 wall. Fire resistance ratings with multi layer designs ul u415 oscillation tested to 1 million cycles to ensure structural performance feature panels with water resistant facings and or mold resistant paper and a water resistant core to help minimize the risk of moisture damage for more information see the following brochures. 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. All too often this plenums and suspended ceilings unbaffled ducts window to window outdoors common heating units transoms and air grilles unblocked joist spaces uncaulked wall perimeters ducts piping and fixtures masonry joints.

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 building construction projects. In the absence of test data standard calculation methods exist which tend to be conservative. There are numerous other issues that need to be addressed to get a more accurate. 1 contains procedures for determining stc values of.

The stc rating of a cmu wall can be estimated based on its weight using the following formula. Stc 14 1w equation 1 is applicable to uncoated fine or medium textured concrete masonry and to coated coarse textured concrete masonry. 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. The standard requires a minimum laboratory stc rating of 50 for party walls and floor ceilings.

The green line is the performance of the wall. Stc 0 18w 40 where w pounds per square foot psf this information is provided as a tool to help estimate. Refer to manufacturer specifications stc what is heard. Because coarse textured units may allow airborne sound to enter the wall they require a surface treatment to seal at least one side of the wall.

Adding green glue to boths side of a wall. When the mass of a barrier is doubled the isolation quality or stc rating increases by approximately 5 db which is clearly noticeable.