WHAT LEVEL OF STC RATING DO YOU NEED?

When deciding what STC rating you should specify; use the following chart to in light your decision:

STC	PRIVACY AFFORDED
25	Normal speech easily understood
30	Normal speech audible, but unintelligible
35	Loud speech understood
40	Loud speech audible, but unintelligible
45	Loud speech barely audible
50	Shouting barely audible
55	Shouting not audible

U.S. Dept. of Commerce / National Bureau of Standards

STC OF FAMILIAR CONSTRUCTIONS

Here are some STC from typical building items and materials, to give you an idea how an operable partition compares.

STC	CONSTRUCTION
18	Hollow-metal door
22	Solid wood door
26	1/4" plate glass
32	1/2" plate glass
38	1/2" drywall on wood studs, both sides
42	5/8" drywall on steel studs, both sides
46	8" hollow concrete block
50	Double 5/8" drywall on steel studs, insulated
53	12" poured solid concrete wall

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