What Is Galvalume?

Bethlehem Steel introduced the Galvalume coating to the construction industry in the early 1970s.

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.

  • Zinc bonds with the steel surface to create a barrier to corrosion-causing moisture.
  • Aluminum is a metal that naturally resists corrosion and reflects heat too.
  • Silicon enhances the adhesion of the coating, keeping it in place when the steel is rolled, stamped or bent.

This process/product 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.