The many advantages offered by metal roofs make them popular choices for residential, commercial, industrial and agricultural steel buildings. Aside from durability, portability, energy efficiency, fire resistance, versatility and hail and wind resistance, metal roofs are lightweight and possess high strength to weigh ration. That is why they are often used to cover large steel buildings such as factories, warehouses, and airplane hangars.
Metal roofs for steel buildings come with protective coatings to make them more durable and corrosion resistant. Some of them are coated with an alloy of zinc and aluminum. Others are metallic coated with a blend of zinc, aluminum and silicon and sold under various trade names such as “Zincalum”, “Galvalume”, etc.
Anti-corrosion coatings stop rust and block corrosion on metal roofs of steel buildings. These products form a barrier coating to insure protection especially in high corrosive, high humidity, and high salt (marine) environments.
Various other types of protective coatings for metal roofs of steel buildings make these roofing systems energy efficient, saving up to 20-30% on air-conditioning costs. These materials have the ability to reflect the visible, infrared, and ultraviolet wavelengths of the sun, thereby reducing heat transfer to steel buildings.
Properly maintained metal roofs can provide protection for steel buildings for generations. However, although they come with protective coatings mentioned above, these may degrade and metal roofs may benefit from a new and reliable protective coating.
The different types of coatings used for metal roofs of steel buildings include asphalt and polymeric (elastomeric) coatings. Asphalt coatings, which may be solvent or water-based, have reflective properties. However, polymer modified asphalt coatings offer improved elongation and recovery properties when compared to conventional asphalt coatings.
Elongation and recovery are crucial to any metal roofing system because metal roof panels expand and contract as the temperature changes. Pigmented latex coatings are the typical materials used in coating metal roofs for steel buildings. These materials offer a wide range of resistance to chemicals, oils and solvents, and also have good elongation and recovery. Coatings made from polyurethane are commonly used in areas where industrial chemicals or oils are present.
Elastomeric coatings that are solvent-borne have good elongation and recovery. However, they have less resistance to solvents and oils, which is why these coating are not used in steel buildings intended as restaurants, where oils and solvents are present.