... made from color steel coil. And it is light, weatherable, stain-resistant, and easy to be welded, and its structure strength ... such as airport, , railway station, conference and exhibition center, stadiums, university buildings and so on.PerformanceExcellent self-tightness, free expansion ... as weldable ability of metal renders impeccable and waterproofing performance. TRAPEZOID CORRUGATED STEEL SHEET