Stc Rating Roof Assemblies

Sound transmission class the decibel db is used to express sound intensity or loudness the more intense a sound the higher the 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.

Stc rating roof assemblies.

Joined oct 25 2009 messages 10 776 location so. The same code states that floor ceiling assemblies between dwelling units or. 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. Dec 14 2011 4 you wont find roof stc ratings.

In 1961 stc was introduced as the method for comparing various wall ceiling floor door and window assemblies. Metal stud walls perform better than wood stud walls. International building code requires 50 stc between adjacent dwelling units. Insulation will noticeably improve the stc rating of an assembly.

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. Joined oct 20 2009 messages 172 location tucson az. Staggered or double stud walls are higher rated than single stud walls.

Comply with fire resistance requirements under evaluation reports of ul u336. 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 load bearing walls. 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.

Although that ll help you meet code it doesn t mean it s sufficient to block out the noise tenants expect. 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. There are a number of other building codes with stricter regulations including the national. Roofing assemblies with densdeck roof boards first to achieve industry leading 61 stc and 49 oitc ratings testing confirms assemblies using densdeck roof boards from georgia pacific gypsum offer.

Moisture resistant assemblies aesthetic assemblies sa932 sa933 sheetrock gypsum panels submittal sheet wb1473 usg area separation walls achieve up to 60 stc offer 2 hr. 5 or 6 points in laboratory stc ratings for essentially similar assemblies.