A. Todd Miller, president of Classic Metal Roofing Systems in Piqua, Ohio, responds: Aluminum is a perfectly viable material for standing seam, though probably 85 percent of metal standing-seam roofing is produced from either galvanized steel (which has a protective metallic coating that is primarily zinc) or galvalume (which has a protective coating that is primarily aluminum). Aluminum and copper each make up about 5 percent of the market, with other types of metals — zinc, stainless, terne — accounting for the remaining 5 percent.
One advantage of aluminum is its permanent rust resistance. Even though aluminum roofing always has a prepainted finish, less care is required during installation to protect cut edges or prevent minor scratches than with steel roofing, most of which is also prepainted (though galvalume is sometimes supplied with a clear-coat finish). Also,...
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