Corrugated bituminous roofing sheet - has two impregnated glass-fibre sheets bonded by bitumen with outside gravel chipping surface and inside aluminium sheet lining

摘要

The corrugated roof lining has two parallel sheets of glass-fibre (1, 2) which are impregnated thoroughly with bitumen (3). The bitumen has powdered silica added to it when molten to give improved strength and abrasion properties. A thin bituminous layer (4) binds the two sheets together. The upper surface (5) is impregnated with gravel or late chippings and the lower surface has a lining (6) typically of aluminium sheet to give fire resistance.