If you’ve shopped for metal roofing, you’ve seen the word galvalume. It’s not a brand or a color. It’s the coating on the steel, and it’s a big reason a metal roof lasts for decades. Here’s what galvalume is and why it matters.

What galvalume is

Galvalume is steel coated with a mix of aluminum and zinc. The aluminum gives long-term corrosion resistance, and the zinc protects the cut edges. Together they guard the steel far better than either one alone, which is why galvalume is the industry standard base for painted metal roofing.

Galvalume vs galvanized

For most roofs, galvalume wins on lifespan. Galvanized still has its place, but galvalume holds up longer in the wet-dry cycles we get across the Northwest.

How long it lasts and where it works

A galvalume-based painted panel can last 40 years or more. It performs well almost everywhere, with one exception: it doesn’t love constant contact with concrete, mortar, or heavy salt spray, so those spots need extra planning. Our panels use a galvalume base under a Sherwin-Williams WeatherXL finish with a 40-year paint warranty. To pick the right thickness, see our gauge guide.

FAQ

Is galvalume better than galvanized?

For roofing and siding, usually yes. It resists corrosion longer thanks to the aluminum in the coating.

Can you get galvalume in colors?

Yes. Most of our painted panels are galvalume steel with a painted finish. Browse colors (MCA).

Bottom line: galvalume is the durable, aluminum-zinc coated steel under a good metal roof. Ask us which panel and gauge fits your project.