A three-layer material. The loadbearing portion consists of a PE grid providing the necessary strength; the top and bottom layers of this polyethylene film providing waterproofing capability. For increasing the effect of vapor permeability, this film has micro-perforations over the entire surface area. Used as waterproofing film in ventilated pitched roof systems. Protects the attic space under the roof from dust, soot and serves as protection against the seepage of residual water into thermal insulation. It simultaneously allows water vapor permeation and ventilation of the interior spaces of buildings. The SPECIAL version of the film is non-flammable.