learn how to choose the best non-painted metal products for your project
When it comes to metal roofing and siding, Galvalume® and galvanized steel are two of the most commonly used coated metal products without pre-painted colour. While they may look similar at first glance, their coatings, performance, and ideal applications differ in important ways. Understanding these differences can help you choose the right material for your project.
What Is Galvanized Steel?
Galvanized steel is carbon steel that has been coated with a layer of zinc to protect the steel core from corrosion. This zinc coating acts as a barrier against moisture and oxygen, slowing down rust formation.
The durability of galvanized steel depends largely on the thickness of the zinc coating. The thicker the zinc layer, the longer it will take for corrosion to reach the steel substrate. Common coating designations include G40, G60 & G90 (the option we offer)
Galvanized steel has a bright, shiny surface, which can be a major advantage if you’re looking for a reflective or high-gloss finish. However, some people prefer a more muted, matte appearance, which is where Galvalume® stands out.
What Is Galvalume® Steel?
Galvalume® steel (also known as AZ50) also has a steel core, but its protective coating is made from a blend of zinc, aluminum, and silicon, applied through a hot-dip coating process. This unique combination gives Galvalume® excellent resistance to oxidation and corrosion, particularly in environments where moisture exposure is a concern.
Compared to galvanized steel, Galvalume® has a more subtle, matte finish, which many homeowners and designers may prefer.
Corrosion Resistance: How Do They Compare?
When it comes to corrosion resistance, Galvalume® generally outperforms galvanized steel in most non-agricultural environments. While galvanized coatings rely solely on zinc, the aluminum content in Galvalume® provides enhanced protection against rusting, especially when exposed to water.
That said, corrosion resistance isn’t one-size-fits-all — the environment matters.
Best Choice for Livestock Facilities
For buildings that house animals, galvanized steel is the better option. Animal urine and waste create a highly corrosive environment. In these conditions galvanized coatings perform better and last longer, while Galvalume® corrodes significantly faster when exposed to animal urine. The higher zinc content in galvanized steel helps protect the material under these harsh conditions, making it more suitable for barns, feedlots, and other animal confinement spaces.
Galvalume® is also not compatible with all building materials. When it comes into contact with certain dissimilar materials, it can experience galvanic corrosion, potentially leading to premature roof or panel failure. Materials that should not be used in direct contact with Galvalume® include Concrete, Mortar, Brick, Copper, Iron, Lead or Treated Lumber.
Final Thoughts
Both Galvalume® and galvanized steel are excellent choices for roofing and siding — when used in the right applications.
- Choose Galvanized Steel if:
- The building houses livestock
- You want a brighter, shinier finish
- Maximum zinc protection is required in harsh agricultural environments
- Choose Galvalume® Steel if:
- Superior corrosion resistance is needed in wet or non-agricultural settings
- A matte, modern appearance is preferred
- Material compatibility can be carefully managed
