For installing Click and Faltz folded covering systems, when installed on a continuous support, Wetterbest provides a special membrane made of anti-condensation foil on which a layer of polyamide fibres is glued, which facilitates air circulation between the negative side of the covering panels and the roof boarding support. The height of approximately 8 mm of the diffusion layer also prevents the imprinting in panels of the boards that constitute the installation support.