The canvas of the vapor barrier film is installed in an overlap at least 20cm. To seal the vapor barrier layer at the joints, the vapor barrier film is glued with a double -sided adhesive tape. Sometimes a vapor barrier uses a metallic pale film. When using a film with a metallic spraying between a layer of insulation and a vapor barrier film, a ventilation gap is left at least 10 mm. After covering, a layer of steam -permeable film is covered with black and finishing cladding, which uses plywood, fiberboard or lining plates.