Our metal roofs are as strong as steel because they are steel. Typically, the shingle consists of several layers. At the core is what is called Galvalume Aluminum-Zinc Alloy Coated steel Sheets are galvanized with both zinc and aluminum. This system of galvanizing the metal roof panel insures the durability and heat resistance. One of the benefits of Stone Coated Metal Roofing, Standing Seam, Mechanical Lock metal roofing is that metal will keep your attic up to 30% cooler, reducing the load on your HVAC units, Saving you money now and in the future.