Metal roofs, in particular steel roofs for homes, are not a new concept. However, all-metal paneling and roofing materials need protection from oxidation. Since 1836, steel roofs have been protected by applying a zinc alloy to them, also known as galvanizing steel.  

However, in 1972, a company called Bethlehem Steel found a new way to protect steel from corrosion by using another material called Galvalume. We’re going to quickly give you an insight into this roofing material.

What is it?


This material is a protective coating on metals, predominantly steel, made up of 55% aluminum, 43.4% zinc, and 1.6% silicone. The process to make Galvalume is similar to galvanizing in that carbon steel is hot-dipped. However, unlike galvanized steel, which is hot dipped only in zinc, this is hot dipped in aluminum and zinc, giving an extra sheath of protection to the base metal. 

The primary purpose of Galvalume is to protect iron-based alloys from being prone to rust. In the case of steel with a Galvalume coating, the steel deals with oxidation thanks to the protection of aluminum, zinc, and silicone.

As in the case of galvanized metal, the zinc comes into contact with the elements and oxidizes before the steel does.

Galvalume vs galvanized steel

The main difference between Galvalume and galvanized materials is in the composition of the protective coating. While the latter has a protective layer of zinc, this has almost equal parts of zinc and aluminum with trace amounts of silicone.

These extra components give this roof panels extra protective abilities, especially against water and other liquids that accelerate the oxidation process. Simply put, even after decades of use, Galvalume-coated steel is likely to remain rust-free longer when compared to galvanized steel.

An added bonus is that the material is also aesthetically more pleasing to the eye than galvanized metals are. 

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Best uses for Galvalume

A lot of commercial buildings like hospitals, schools, and supermarkets use Galvalume roofing and wall panels. Residential projects ranging from modern condos to homes featuring classic architectural styles where a steel roof is the most practical roofing material also feature Galvalume.

Pros and cons

galvalume roof

As with everything in the construction industry, Galvalume is also not without its flaws. Let’s take a look at the pros and cons of this material.

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Pros of Galvalume


As a material, this roof is a lot more durable than galvanized metal. It deals with corrosive agents like rain, snow, and ice. Most manufacturers offer at least a 20-year warranty on their products. Some come with a paint warranty that exceeds that time period.

In fact, it could be more than 50 years before rust begins to affect the material.


With prices ranging from around $5 to $15 per square foot, Galvalume is among the most affordable roofing materials available in the market.


Galvalume has certain self-healing properties. When the material is cut to shape, the edge creep allows the red rusting at the edges to self-heal and prevents the discoloration from spreading. 

Cons of Galvalume

Not animal friendly

If you’re living on a farm and considering this roofing or panels for an animal shelter, then we’d advise dropping the plan immediately. Especially if there’s a chance of livestock coming into contact with the material.

While not too many materials do well when they come into contact with animal urine, Galvalume panels start to degrade especially quickly. 

Don’t use it with all materials

Galvalume is not compatible with all construction materials. In fact, if you use it with incompatible material, it could cause galvanic corrosion. This can result in the material degenerating at a faster than usual rate.

The list of materials Galvalume is not compatible with includes brick, mortar, concrete, iron, and copper.

Read more: Snow blowing in roof vents

An introduction to Galvalume for metal roofing was last modified: December 12th, 2022 by Narayan Shrouthy
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