Brian writes from Maryville, Tennessee: “What is the NRC (Noise Reduction Coeffeciant) in your R-11 Quiet Zone Batt?
The short answer is 1. A longer and more comprehensive answer includes the following information: QuietZone® insulation is for interior walls where the temperature is generally the same on both sides. The wall therefore does not require R-values so the company does not test or label QuietZone insulation for R-value. If R-value is needed or required, you should use a thermal insulation product. NRC is a value that represents the amount of sound absorbed prior to the sound returning from a surface. In order for this value to be accurate, the insulation has to be exposed, meaning no drywall on one side. NRC is a single-product value and has absolutely nothing to do with the effectiveness of a wall assembly in keeping noise from traveling through it. Once the drywall is installed over the insulation, the number is meaningless. Light density Fiberglas™ insulation batts that are 3.5 inches thick have an NRC of 1.05 when mounted next to drywall, or 1.00 when mounted 40mm away from drywall. NR
