ALUMINUM ROOFING is a very light metal with a specific weight about a third that of steel. Aluminum naturally generates a protective oxide coating and is highly corrosion resistant making it excellent for such conditions as marine environments. Different types of surface treatment such as anodizing, painting [such as Kynar500 used on metal roofing] can further improve this property. It is particularly useful for applications where protection and conservation are required. Aluminum is 100 percent recyclable with no downgrading of its qualities. The re-melting of aluminum requires little energy: only about 5 percent of the energy required to produce the primary metal initially is needed in the recycling process. Metal roofing has a 25% recycled content in new roofing.