Breathable roof membrane Use: Breathable roofing underlay positioned immediately above the insulation layer in a warm pitched roof, or in a cold pitched roof (ventilated or unventilated). Breathable roofing underlay for use under tiles and sheeted roofs, over open rafters or on to fully boarded substrates. Breather membrane for timber frame wall construction. Features: High performace breather membrane Constructed from high tensile spun-bonded polypropylene layers Higher levels of water resistance Full moisture vapour permeability Breathable underlay for tiled and slated pitched roofs Eco-friendly to be completely recyclable.