Galvalume Vs Galvanized Metal Roof
Galvalume metal roofs offer better surface protection than galvanized roofs however they re more vulnerable to scratches blemishes and cut edges.
Galvalume vs galvanized metal roof. Standing seam metal roofs are commonly made from a material called galvalume which is steel that has been super galvanized this super galvanizing coating is an aluminum zinc alloy. Zinc bonds with the steel surface to create a barrier to corrosion causing moisture. Traditional galvanized metal roofing is a corrugated sheet of carbon steel with a galvanized coating. Iron or steel can be coated with zinc.
Galvalume is roughly twice as resistant to rust and corrosion as the steel used for corrugated metal roofing because of this special galvanizing process. Typical g90 galvanized metal roofing can cost anywhere from 5 00 to 13 00 per square foot and can fluctuate further based on thickness color installation costs location and more. Most galvalume like galvanized steel is coated. This is known as a galvanized metal.
The coating is created by dipping the straight sheet in hot molten zinc. The answer lies in the difference between the two. Galvalume is aluminum and zinc coated steel. Galvalume metal is a high performing option for environments that frequently experience high temperatures and high amounts of precipitation and marine environments.
Instead of 100 zinc the dip is 55 aluminum 43 5 zinc and 1 5 silicon. Studies show that when used on a residential house that a galvalume metal roof will outlast a galvanized metal roof by almost double. Galvanized while both products were developed to essentially sacrifice themselves to protect the steel sheeting they coat the above exposure comparison shows that galvalume performs up to nine times better in fighting corrosion as compared to galvanized coating. The zinc ions bond with iron molecules in the steel to create a shiny rust resistant finish on its surface.
However in the last 20 years the pricing of these two materials has fluctuated back and forth but predictions for november 2019 show galvanized material is about 6 higher in price over galvalume. Similar to galvanized steel galvalume is produced by a hot dip process. Aluminum is a metal that naturally resists corrosion and reflects heat too. Most galvalume metal roofs come with a 25 year warranty if the metal roofing manufacturer is using galvalume with a full az55 coating.
The combination of aluminum and zinc is used once again as a protective layer to the steel.