Galvanized steel has been used in construction for nearly 200 years. In fact, the first use of the term occurred in France in 1836, when inventor Stanislas Sorel patented the galvanizing process.

Today, galvanized steel is manufactured in the same way as it was in Sorel's day. A piece of steel is cleaned and dipped in molten zinc. The zinc then hardens on the steel, creating an additional protective coating. 

This helps the steel resist rust, corrosion, scratches and dents.

Galvanizing is widely used around the world; according to the American Galvanizing Association, in North America alone, galvanizing consumes more than 600,000 tons of zinc per year.

In the 1970s, the American shipbuilding company Bethlehem Steel decided to expand on Sorel's invention. 

The company added the metal to molten zinc and began trying to create a mixture that would yield greater protection. Ultimately, the company settled on an ideal blend, 

and galvalume was born.

Galvalume (a registered trademark of BIEC Intl. Inc., the licensor of the technology), is a coating on steel plate consisting of 55% aluminum, 43.4% zinc and 1.6% silicon. 

The coating provides better protection to the steel from the elements, making it more durable than traditional galvanized steel.

Galvalume roofs and walls are not only durable, but also self-healing. If the steel begins to rust along a cut or exposed edge, the coating stops the rust from spreading.

The main difference between galvalume and galvanized steel is the protective coating around each steel plate. Galvanized steel is coated with zinc while galvanized steel is coated with zinc, aluminum and silicon.

Both are great for roofs, and each has pros and cons. Galvalume is a more durable material and lasts about twice as long as galvanized steel. Galvanized steel tends to cost less (while still offering good protection),

making it a suitable choice for buyers on a budget.

What is the right choice for a galvanized roof vs. galvalume roof?

Whether your roofing project uses galvanized steel or galvalume, it's important to make sure you're using the material correctly. Most importantly, you need to be sure that your structure is suitable for a metal roof.

Galvanized metal is perfect for agricultural spaces like barns or warehouses, or even homes. Galvanized steel offers extra durability for superior protection from the elements, and galvanized steel can be painted to suit your building design or aesthetic.

Galvalume is also ideal for residential, commercial buildings and agricultural spaces. However, it is especially useful in places where extreme weather conditions are more likely to occur. The extra protection provided by galvalume will keep your roof looking better after years of snow, rain, high winds and wide temperature swings.

It is best to speak to a local expert with experience with galvalume and galvanized steel. Experienced professionals can provide the best advice based on the intended use of your building and the expected weather conditions in the area.

No matter what you decide, a steel roof will last longer and provide more protection than wood or asphalt shingles. With a steel roof, whether galvanized or galvalume, you can enjoy durability, safety, and energy efficiency for years to come.