The extra strong vapour barrier with a very rough surface. Starvap 100 fric is used as a vapour barrier and air seal. Its very rough surface allows a high degree of safety during walking. For this reason Starvap 100 fric is generally used in constructions with rafter insulation. Starvap 100 fric has Fire class E according to DIN EN 13501-1 and a fixed Sd value of 100m according to DIN EN 1931.