If you're looking to buy a metal roof, there are lots of different materials to choose from --- aluminum, copper, zinc, galvanized, stainless steel, and Galvalume.The most widely used metal in architectural metal roofing is Galvalume, a steel-based product that can be used for almost every building application.How much do you know about Galvalum?Do you know the advantages and disadvantages of this galvalum roofing material?This article will discuss: What is Galvalume?Galvalume Coil Advantages and Disadvantages of Galvalume.Bethlehem Steel introduced Galvalume coating to the construction industry in the early 1970s.Before Galvalume came along, most metal roofs were galvanized steel.However, because of Galvalume's superior durability and corrosion resistance, 90+ percent of the metal roofing industry switched from galvanized substrates to Galvalume substrates in the mid to late 1990s.Galvalume combines three important, high-performance metals used in roofing today --- steel, aluminum, and zinc.Manufacturers start with a cold rolled carbon steel base sheet that is continuously hot dipped with aluminum and zinc alloy (AZ) to achieve a coating of 55% aluminum, 43.4% zinc and 1.6% silicon.This process allows for one material to have some of the best characteristics of each metal, which is why it is one of the most popular metals used in metal roofing.Galvalum can also be called by the weight of its coating, AZ-50 and AZ-55.One of Galvalume's number one selling points is the 25.5 year guarantee on the substrate, which is sometimes referred to as the perforation warranty.Galvalume systems also often come with a paint warranty further protecting your investment and providing peace of mind that your roof or siding system will last you a long time.(Note: Substrate or paint warranties are NOT available on Galvalume products within 1,500 feet of shore.) Plus, commercial property owners can purchase a weatherproof warranty for their Galvalume roof structure, which ensures the roof is properly installed and adheres to strict installation details.- Corrosion Resistance & Self-Healing Properties