Galvalume roofing material combines three of the most important metals used in roofing today-steel, aluminum, and zinc. Manufacturers begin with a carbon steel base sheet that is then continuously hot-dipped with aluminum and zinc alloys until it reaches a coating consisting of 55% aluminum, 43.4% zinc, and 1.6% silicone. This process allows for one material to have some of the best characteristics of each metal, which is why it's become one of the most popular materials in today's roofing market.
Galvalume is also referred to by its coating weights, AZ-50 and AZ-55. Here's what these two terms mean:
AZ-50 = 0.50 ounces per square foot of the aluminum-zinc alloy coating applied to both sides of the substrate.
AZ-50 is the typical coating weight for painted sheet/coil products.
AZ-55 = 0.55 ounces per square foot of the aluminum-zinc alloy coating applied to both sides of the substrate.
AZ-55 is the typical coating weight for bare or unpainted (often called acrylic-coated Galvalume or Galvalume Plus) sheet/coil products.
Acrylic-coated Galvalume has a slightly heavier coating weight and includes a light acrylic coating that protects the Galvalume coating in the manufacturing process. This acrylic coating will wear off over time with exposure. Though not painted, these products still need to be handled with care, or you risk scuffing or perforating the coating.
Uses for Galvalume Metal Roofs & Walls
Overall, Galvalume is suitable as a roof, wall, trim, accent, and more in most building applications in some of the most extreme environments, including hurricane zones, locations with high rain or snowfall, high-temperature regions, and more.
Some common uses for Galvalume include:
Commercial buildings – Hospitals, schools, stores, government buildings, and more
Residential projects – Single-family, multi-family, condominiums, and more
Architectural structures – Commercial, governmental, residential, and more
Structural/industrial applications – Warehouses, factories, and more
Agricultural – Non-animal confinement spaces, barns, storage, and more
Bare galvalume
Advantages & Pros of Galvalume
Warranties – One of the number one selling points of Galvalume is the 25.5-year warranty on the substrate, which is sometimes referred to as a perforation warranty. Galvalume systems also often come with paint warranties that further protect your investment and provide peace of mind that the roof or wall system will last. (Note: Substrate or paint warranties are NOT available for Galvalume products within 1,500 feet of a coast.) Plus, commercial property owners can buy a weathertight warranty for their Galvalume roofing structure, which ensures the roof was installed correctly and adheres to strict installation details.
Corrosion resistance – When compared to galvanized metal, Galvalume's corrosion resistance is about two to four times better. Galvalume's formula was designed to combine the toughness and strength of zinc with the rust resistance of aluminum. Research conducted by the Metal Construction Association (MCA) indicates that Galvalume roofing could last as long as 40 to 50+ years without any extreme signs of corrosion.
Self-healing properties – All steel-based products have some degree of edge creep from the exposed steel when the coil is cut, but it can be offset by hemming or touching up exposed edges with paint pens. An advantage of Galvalume that stems from this concept is the fact that it has self-healing characteristics that help control the red rusting at the cut/exposed edges. (Note: A small degree of red rusting at cut edges is normal, but with a Galvalume coating, the red rust will eventually stop.)
Economically priced – For the most part, Galvalume is reasonably priced and one of the more affordable metal materials available for roofing products.