STROTEX-Q MEDIUM is a universal four-layer membrane used both on roofs with full boarding and in structures with open thermal insulation. With their innovative technology, Strotex Q membranes equalise differences in water-vapour concentration and so protect the roof's thermal-insulation layer. It protects the thermal insulation from rain and snow from the outside. Every layer of the product contains UV stabilisers that slow down weather-induced ageing. STROTEX-Q is a diffusion-open membrane intended as a preliminary covering layer beneath the roof covering, and it is also an excellent wind barrier for the walls of frame-construction buildings. Because of its low Sd value, it is used on roofs insulated to the full rafter depth, where it is laid directly on the insulation.