The flexible roofing system uses PVC/TPO flexible sheet materials as the outer roof waterproofing layer, with XPS rigid insulation material or rock wool insulation material underneath, and a metal DECK at the bottom. This system is popular in developed countries, mainly because the flexible roofing system has excellent thermal insulation properties, and the roof is flat and easy to cut holes and maintain. In the flexible roofing system, B-DECK is the ideal type of metal DECK, with a 6-inch-wide platform and 1.5-inch wave height, providing sufficient strength and good integration with insulation. Typically, the B-DECK thickness is not less than 0.75mm, a requirement for wind resistance of roofing materials and for better roofing effects. In North America, B-DECK thicker than 0.75mm can replace horizontal bracing with the B-DECK system. Open’s B-DECK has passed the American FM certification.