Seeing metal roof rust is horrifying for many Calgary AB homeowners. Your metal roofs have the potential to last for more than 50-100 years with minimal maintenance. However, accelerated wear and tear aren’t news to metal roofing, especially for homes in high salt air or storm-prone locations. Truthfully, you don’t have a long time with your rusted metal roof, making it imperative to replace them quickly.
Rusted metal roofs have their zinc or aluminum coating fully compromised. Once the steel core rusts in one area, it will continue to spread underneath the zinc or aluminum coat until the entire core corrodes. The time it will take to do this varies between 1-2 years. Truthfully, it’s a crunch period for any homeowner, forcing them to take out loans or borrow money to finance a new roof.
Fortunately, high-quality asphalt shingle roofs can help you immensely. Aside from modest costs, Certainteed roofing shingles have lightweight variations that do not require you to disassemble and tear down your old metal roofing. Plus, if you work with reliable roofers in Calgary AB, you get the best value-for-money installations guaranteeing new and long-term roofing.
Reliance Foundry has an excellent post about the real-time effects of rust on your metal roof’s steel core. Read more about it below.
Stages of rust
During the first stage of rust, red, black, or white deposits become noticeable on the surface of the metal. This typically appears in small patches as the overall color of the metal’s surface becomes spottier and less uniform. In cast iron, this is the first step toward the formation of a permanent patina. Stainless steel depends on a chromium oxide as a protective film, not an iron oxide, so this rust is the failure of that protective film. Still, in stainless steel, Stage 1 represents a superficial problem that can be easily repaired if desired.
For steels and some types of iron, Stage 2 represents the first real degradation to the metal, as scale begins to form with the molecules that make up the first layers of the metal. In many ferrous metals, this scale is uneven, and begins the process of pitting or etching that starts to weaken the material. In cast iron, the scale formed is even and does not lead to etching or pitting.
Several oxides are being produced in this stage. The bright orange/red iron oxide (III) that we associate with rust can be brushed off. It will leave a powdery red pigment on hands or rainwater. The lack of adherence of this oxide is because the red iron oxide molecules are larger than the cast iron molecules that created them.
However, in well-prepared cast iron, oxides that do not flake or run off also form evenly. These are darker, usually brown or coppery colored. This layer of rust builds evenly so that the integrity of the base metal is unaffected. (Continued)
If you have yet to find a dependable roofer to work with, you can always count on us at No Payne Roofing to install the best roofs for you. We are a Certainteed-certified roofing company giving you the best labor and material guarantees in Calgary.