steel aluminum

If you’re deciding what material to purchase for your metal roof, you may have come across terms like steel, galvalume, and galvanized. So what’s the difference between these three options? And how do you know which one is right for you?

Weighing the pros and cons of galvalume and galvanized roofing can certainly be confusing. And since installing a new roof can already be a costly and stressful process, we’re eager to offer our expertise. We’ve created a helpful guide to walk you through choosing the right roofing material for your needs.

Read on to learn more about galvalume vs galvanized and the benefits of a galvalume roof.

What Is Galvalume?

Galvalume is one of the most popular roofing materials on the market today and is a type of steel roof coating made from aluminum, zinc, and silicon. Aluminum makes up more than 50% of the coating, making it more resistant to corrosion.

Invented by Bethlehem Steel construction company in the early 1970s, galvalume coating is made by hot-dipping the metals onto steel coils to make it adhere to the material. The coating can be left as a plain mill finish, or painted in a variety of colors.

What Is Galvalume Used For?

The main purpose of galvalume is to protect steel from oxidizing (rusting), which compromises the integrity of the material. It is used for many purposes, but the most common application is for outdoor metal paneling and metal roofs. It might be installed on a wall, building trim, or as an accent, especially in climates subject to hurricanes, humidity, extreme heat, or high rainfall or snowfall.

Galvalume is not an ideal material for fastener installation, or for environments when it may be exposed to alkaline, which compromises the aluminum within the coating. It is also not well-suited for environments where it could get scratched or dented, since damaged galvalume does not perform well.

Finally, galvalume metal roofs should not be used in buildings that house animals, since manure breaks down the galvalume coating over time. 

Benefits of Galvalume

Galvalume offers many unique benefits, especially in comparison to galvanized steel. Here are just a few of the reasons you may opt for galvalume.

1. Resistant to Corrosion

Galvalume is most valued because of its resistance to corrosion. Because aluminum is added to the coating, it is twice as resistant to corrosion as galvanized steel. The material is well-suited for environments with exposure to high humidity and extreme weather.

2. Lightweight

Because galvalume is lightweight, it has an impressive strength-to-weight ratio. The flexible coating won’t crack or flake off, even when the sheet metal is manipulated or bent.

3. Energy Efficient

Galvalume is highly reflective and resistant to extreme temperatures, meaning it minimizes absorption of heat and boosts energy efficiency when used as a roofing material. Using galvalume roofing panels will reduce both cooling and heating expenses throughout the year.

4. Affordability

Many people choose galvalume because of its low price point in comparison to galvanized steel. It is a low-maintenance material that will last for at least 40 years, providing significant savings throughout its lifetime.

6. Longevity

All metal roofing offers significant longevity, but galvalume stands out for its superiority in standing the test of time. While a galvanized steel roof may start aging within 10-15 years, galvalume roofing won’t start to wear out for at least 20-30 years.

7. Versatility

Galvalume is extremely versatile and can be used in a variety of settings. It can be rolled or bent with ease, or stamped to change the appearance. The panels can even be installed over asphalt shingles or over the top of wood underlayment.

What Is the Difference Between Galvanized and Galvalume?

As you now know, galvanized and galvalume roofing materials have distinguishing characteristics and are not interchangeable. So what are the main things to note about galvalume vs galvanized steel? Here are some key points.

Chemical Makeup

Galvanized steel is made completely of zinc, while galvalume includes aluminum, zinc, and a small amount of silicon. This provides superior durability and resistance to corrosion in comparison to galvanized coating.


Galvalume and galvanized steel are both made through a hot-dipping technique and have a similar thickness, which is usually around 1 millimeter. This thickness may vary slightly from one material to the next, but if the galvalume and galvanized steel coating are of the same thickness, the galvalume coating will usually last longer than the galvanized coating.


As we’ve mentioned already, galvalume tends to last almost twice as long as galvanized steel before it shows any signs of wear. This is mainly due to the aluminum that is added to the coating to prevent oxidation.


Thanks to its corrosion-resistant properties, galvalume is ideal for humid and hot environments, commercial buildings, residential homes, storage units, and more. Galvanized metal roofing is better suited for dry climates free of major air pollution or pooling water.

Ability to Self-Heal

Most steel roofing materials end up having some “edge creep” near the edges where the panel was cut. Fortunately, galvalume is “self-healing,” meaning it eventually stops creeping and won’t spread rust all over the panel. But galvanized steel is not self-healing—the edge creep rusting will only worsen over time.


Most galvalume roofing materials are included in a warranty, because they’re known for being durable and long-lasting. However, many galvanized materials do not have a warranty, since they can be unpredictable and unreliable, especially once they begin to rust.


Because galvanized and galvalume steel are made in a similar fashion, they’re sold at a similar price. All steel roofing is more expensive than asphalt shingles, but the long-lasting nature of the product means it is usually more cost-effective overall.


Galvalume is generally considered to be more favorable in appearance when compared to galvanized steel. The two coatings’ differences are subtle, but galvalume offers a smoother, matte appearance, while galvanized coating is more rough and shiny. 

Purchase Galvalume Today

Choosing the right type of steel coating can be overwhelming, but now that you know more about these types of roofs, you’re better equipped to handle the big task of installing a new one.

Does galvalume sound like the right choice for your next project? If so, contact 1st Coast Metal Roofing Supply to order your high-quality galvalume materials. We’re happy to answer any of your questions about galvalume metal roofs and help you decide if you’re still comparing galvalume vs galvanized roofs. Get in touch today for a free quote.