Abstract
Vapour barriers were originally intended to keep building assemblies from getting wet, but they can sometimes end up preventing assemblies from drying out. An innovative new product to manage moisture accumulation in the building envelope, however, may be able to address both issues: while the product acts as a vapour barrier under most conditions, it also allows excess moisture to escape. The Canadian Construction Materials Centre (CCMC) set out to determine whether this product can serve as a vapour barrier and an air barrier system and whether it conformed to the intent of applicable building code requirements. In collaboration with NRC-IRC researchers, CCMC developed a testing protocol for its evaluation, which was based on laboratory testing requirements for vapour diffusion, air leakage control and durability.,Article,Published.