Belgavar plus is a vapour control layer and air tightness membrane with humidity variable vapour resistance, to allow a better protection of challenging building structures like flat roofs or non-breathable insulation layers on the exterior side, such as PIR insulation on top of the rafter level. The membrane is able to change the sd value in a range between 0.9m and 12m.
The fleece reinforcement at the backside of Belgavar plus makes the membrane suitable for heavy insulation materials like cellulose.
Dimension (EN 1848-2): 50 m x 1,50 m / 75m²
Weight (EN 1849-2): 130 ± 10% g/m²
sd value (EN 1931): 0.9 m < sd < 12 m
Fire class (EN 13501): class E
The following preconditions must be strictly followed:
• no shadow on the roof from trees, terraces, solar panels etc.
• dark-grey or black roofing
• a blower door test to check the qualified installation is mandatory
• only a highly vapour-permeable finish on the inside e.g. plasterboard or fibreboard is allowed
• green roofs are only possible to a maximum thickness of 120mm (50mm ballast and 70mm substrate)
• the timber (roof) structure must be kept dry during the construction phase
• not suitable for permanent damp spaces such as saunas and swimming pools