Understanding the acoustical implications of Underwriters Lab (UL) listings

With today's ever more complicated building design, acoustical consultants should be aware of how their recommendations affect other aspects of floor/ceiling design. The acoustical ratings must be balanced with the need for fire rated assemblies as well as structural requirements. As the industry leader in the listing of fire rated designs, the Underwriters Lab (UL) maintains a list of assemblies that will meet various levels of fire resistance. These listings are very detailed and even slight changes to the design can have a profound impact on the assembly's fire resistance rating. This paper will compare various listed wood-frame floor/ceilings assemblies with respect to acoustical design. These comparisons will include fiberglass thickness, number of drywall layers, resilient channel spacing, and types of resilient sound clips. The general affect of each of those variables on acoustical performance will be shown. Several insights will also be shared from the acoustical supplier's perspective on the UL listing experience.