Galvalume metal roof and siding panels have a coating of zinc, aluminum, and steel which gives it superior corrosion resistance and longevity compared to galvanized steel. Galvalume features superior performance benefits including corrosion resistance, self healing properties that will stop rust from spreading, and less shine versus galvanized steel. Galvalume coatings are now the most prevalent corrosion resistant coating. Galvanized is rarely used on steel panels unless it's an agricultural application.