Galvanized corrugated metal roofing is steel sheet formed into ridged panels and coated with zinc, and its defining feature is the zinc layer that protects the steel from rust. The corrugation, or repeating waves, adds stiffness without adding a lot of weight. That makes the panels strong enough to span open framing while staying easy to handle and install. You will see this material on barns, workshops, carports, sheds, and some homes, especially where a rustic or utilitarian look is acceptable.