Waterproofing system The Mech-Bond mechanically bonded bituminous waterproofing system for roofs is now available from Vulcanite. It comprises a fleece-backed polyester underlay which is coated with a modified bitumen and mechanically fixed, and a cap sheet torch welded directly onto the underlay to provide the waterproof membrane. The Mech-Bond is recommended for positions where bitumen boilers are not permissible. Vulcanite …