Once properly installed, a metal roofing sheet is capable of lasting as long as the house is standing for the reason that metal roofing sheet doesn’t rot or crack, neither does it warp or curl. The shingles or panels doesn’t break or split, nor can they burn and the design doesn’t peel off for ages. Metal roofing sheet seals off water, capable of surviving high winds and it can shed snow and thawing quickly. Metal also can resist fire, insects, mildew and wane.
http://www.sdhengjiahaya.com/metal-roofing-sheet/