Stc Rating Roof Assemblies

The stc rating shown reflects testing or evaluation of an assembly with one or more products under test conditions and may not apply to all products listed for each assembly.

Stc rating roof assemblies.

Db level the sound transmission class stc is a numerical rating of the ability of a wall floor ceiling assembly or any other building element such as a door or window to minimize sound transmission. In 1961 stc was introduced as the method for comparing various wall ceiling floor door and window assemblies. While this is a good. The standard requires a minimum laboratory stc rating of 50 for party walls and floor ceilings.

In order to properly ascertain the stc rating of a wall or other assembly there are two approaches lab comparisons. Impact noise tested on floor ceiling systems only is reported as the impact insulation class iic. Airborne sound insulation is reported as the sound transmission class stc. 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.

The same code states that floor ceiling assemblies between dwelling units or. What are stc ratings. 3 5 8 metal studs 5 8 gyp 2 layers total no insulation. 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.

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. Section 1207 of the 2015 ibc states that wall and floor ceiling assemblies separating dwelling units must meet a sound transmission class stc rating of 50 or 45 for field tested assemblies tested in accordance with astm e90. Helps ensure that partition sound performance matches the promise of sound tests by sealing off spaces at partition perimeters and around cutouts can increase the stc rating of a double layer steel framed partition from 29 to 53 stc an integral part of high performance usg partition designs for attenuation of low frequency sound from machinery and music suitable for use at the perimeter of fire rated wall assemblies for more information see the following brochure. Sound ratings gypsum board assemblies are laboratory tested to establish their sound insulation characteristics.

Staggered or double stud walls are higher rated than single stud walls.