Is GALVALUME® Coating the Right Choice for My Steel Building?

Published March 9, 2015 by Whirlwind Team

describe the imageIf you are researching steel and metal building construction, then you know moisture is your building's worst enemy. While steel and metal buildings are known for withstanding high winds, fires, pests and other typical downfalls of traditionally constructed building, the steel components must be protected from moisture in order for your building to live up to its anticipated reputation.

GALVALUME® is a proprietary, trademarked coating that is comprised of 55% aluminum, 43.4% zinc and 1.6% silicon. Although it was created in 1972 by Bethlehem Steel, it can be found marketed under other names as well with slight variations in composition. It is important to note that GALVALUME is NOT the same as galvanized steel.

Galvanized steel is one example of a protective steel coating galvanization is derived purely from zinc, rather than the aluminum, zinc and silicon alloy used for GALVALUME. The alloys used for GALVALUME create a one-two-punch; the aluminum is provided to prevent corrosion while the zinc makes the steel components more durable. Although GALVALUME is used for siding elements, its most common application is for metal roofing components.

A few additional facts about GALVALUME:

  • It should never be used on or near concrete or mortar. These are both highly alkaline materials and will react rapidly with the aluminum, causing corrosion. Choose galvanized steel if the steel components will be used on, in or adjacent to concrete or mortar environments.
  • Due to GALVALUME's noted durability, GALVALUME roofs are typically offered with a 25-year warranty, although historically speaking they often last for upwards of 40 years or more.
  • When GALVALUME roofs are used in residential applications, they tend to last twice as long as their traditional asphalt roof counterparts.

Other advantages of a GALVALUME roof system include:

Energy Efficiency

Any metal building component with a long life span enhances your building's lifetime energy efficiency because it requires less supplies and energy to maintain it over time. However, GALVALUME roofs can also be finished with a reflective coating that reflects the sun's UV rays, significantly reducing passive solar gain and environmental heat island effects.


The lightweight and easy-to-install panels make GALVALUME a versatile choice for both structural and architectural purposes. It can also be installed over existing applications. Roofs installed where aesthetics matter can be painted virtually any color to enhance the overall exterior design of the building. However, since it is still incredibly durable in its unpainted version, GALVALUME is also popular for more industrial and out-of-site commercial applications.


The combination of protection, durability and low-maintenance features exhibited by GALVALUME make it a low-cost roofing and siding option. Pair that with the energy efficiency noted above and GALVALUME will make a steep dent in your building's lifetime maintenance and replacement costs.

What Else Can I Do to Protect My Metal Building from Corrosion and Moisture Damage?

Choosing metal building components with high-quality coatings, like GALVALUME, is the first step to protecting your building from corrosion and moisture damage. There are additional steps you can take to support and enhance your structure's longevity.

These include things like installing adequate gutters, downspouts and providing adequate on-site draining so rain, snow, ice melt and the water from exterior condensation is directed off the roofs and away from the building structure. Your roofing system itself can be designed to channel moisture off its surface in geographic locations that are prone to high rain fall or snow melt.

Also, talk to your building manufacturer or contractor about the insulation and ventilation techniques that will prevent interior condensation from causing a problem. Accumulated moisture in attic and interior wall spaces is dangerous as evidence of these issues often appears after the damage has already been done.

Contact Whirlwind Steel to learn more about GALVALUME and other protective coatings and features that will allow your building to look and function its best for decades to come.





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