SOPRASEAL HVM

SOPRASEAL HVM is a variable-permeance air/vapour barrier membrane with high tear resistance. It is applied on the warm side of external wall assemblies as well as on horizontal surfaces in attics. SOPRASEAL HVM also acts as a retention membrane for SOPRACELLULOSE. Its vapour diffusion permeance varies as it adapts to the relative humidity in the air. SOPRASEAL HVM has a low water vapour permeance in winter, when relative humidity is low, while in summer or spring, its permeance is higher as the relative humidity increases. This protects the wall cavity from water vapour penetration (in winter) and allows it to dry (in summer).