Performance of Innovative Vapor Retarders Under Summer Conditions

Abstract

Moisture problems resulting from conventional vapor control strategies have inspired the development of innovative vapor retarders. The performance of two such retarders, the water permeable Hygrodiode and the humidity controlled Smart Retarder, has been examined by laboratory and field tests. The results show that both innovative retarders improve the drying potential of an assembly compared to a traditional polyethylene film. The degree of improvement depends on the application. The Smart Retarder is favored for walls because summer condensation is less pronounced than in roofs where both retarders perform equally well. For flat roofs with possible leaks in the membrane the Hygrodiode could be of advantage due to its capacity to absorb and transport liquid water.