The vapour barrier with anti-slip surface. Starvap 100 ribbed is used as a vapour barrier and air seal. Its slightly rough surface provides increased walking safety. For this reason Starvap 100 ribbed is often but not exclusively used in constructions with rafter insulation. Starvap 100 ribbed has Fire class E according to DIN EN 13501-1 and a fixed Sd value of 100m according to DIN EN 1931.