Rates the ability of a ceiling or wall panel or other construction to absorb sound. NRC is the fraction of sound energy, averaged over all angles of direction and from low to high sound frequencies, that is absorbed and not reflected. Increases stability and moves cut edge of tee out of the visible plane of the ceiling. In suspended ceiling construction, the space between the suspended ceiling and the main structure above. A number measuring a materials resistance to heat flow.
R stands for resistance, the inverse of conductivity.
Values reported in this catalog were determined by the ASTM C 518 test method. Rotary Stitching Process by which two vertical layers of steel are stitched or bonded together to form a more homogeneous component exhibiting increased column strength, torsional strength, and overall handleability. Armstrong is the only grid manufacturer to employ this technology. For applications where cleanliness is a priority, acoustical units may require cleaning beyond normal maintenance procedures. Acoustical panels with special facing materials such as Mylar or vinyl film offer superior scrubbability without compromising panel finish integrity.