In many larger buildings, the area above the suspended ceiling is used as an air plenum. Model codes restrict the surface burning characteristics of the materials that can be installed in air plenums.
Various tests are used to evaluate the surface burning characteristics of constructions materials. The most common requirement is to restrict materials permitted within plenums to those meeting a 25/50 flame spread/smoke developed when tested in accordance with ASTM E84. As a reference, asbestos cement has a 0/0 flame spread/smoke developed rating and red oak has a 100/100 flame spread/smoke developed rating.
FlowGuard Gold® pipe and fittings have been listed by ICC-ES under PMG 1264. The following models have been tested water- filled or dry in general accordance with UL 723/ASTM E84 test methods for surface burning characteristics and have been found to meet the 25/50 flame spread/smoke developed requirements of the International Mechanical Code® (IMC) and the Uniform Mechanical Code® (UMC) for installation in ducts and plenums.
- 1/2″ – 2” water-filled FlowGuard Gold CPVC pipe and fittings have a flame spread index of no more than 5 and a smoke developed index of no more than 35.
- 1/2″ – 2” dry FlowGuard Gold CPVC pipe and fittings for condensate lines have a flame spread index of no more than 5 and a smoke developed index of no more than 25.