Stc Ratings For Concrete Floor Assemblies

Sound transmission class stc provides an estimate of the acoustic performance of a wall in certain common airborne sound insulation applications the stc of a wall is determined by comparing sound transmission loss stl values at various frequencies to a standard contour stl is the decrease or attenuation in sound energy in db.

Stc ratings for concrete floor assemblies.

Determining sound transmission class stc for 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. In 1961 stc was introduced as the method for comparing various wall ceiling floor door and window assemblies. While this is a good.

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 is calculated by taking the transmission loss tl values tested at 16 standard frequencies over the range of 125 hz to 4000 hz and plotted on a graph. In order to properly ascertain the stc rating of a wall or other assembly there are two approaches lab comparisons. The standard requires a minimum laboratory stc rating of 50 for party walls and floor ceilings.

The estimated ratings are based on laboratory test results from various compendiums of stc ratings. First up if the original architectural drawings are accessible it may be possible to look up the design assembly and postulate the intended stc rating by comparing that data to existing lab test data.