1 ) Breathable Membrane is a water resistant membrane but with high vapour permeability, use as diffusion open roofing felts under pitched roof tile or vapour permeable barrier housewraps on timber frame walls
1 Breather membrane functions as a weather-resistant barrier, preventing rain from getting into the roof or wall assembly while allowing water vapor to pass to the exterior.
2 Breather membrane may also serve as an air barrier if it is sealed carefully at seams.
3 Breathable Membrane have good "water resistance", good "water vapor permeability", and good "air barrier properties".
2)
breathable roofing membrane Specification