Willus HI-RIB roof and wall cladding system is available in the following base material in standard execution. Galvalume high tensile cold rolled steel 345/550 as per AS-1397 standard (AZ 150 gsm/m²) Zinc-Aluminum alloy coating mass, total of both sides, 550/345 Mpa yield strength conforming to AS-1397. The roof sheeting is 0.47 mm thick. Hi Rib Bare Galvalume Wall cladding is 0.50mm thick. Hi Rib Colored coated Galvalume.