Metal roofs are sturdy and last several years compared to other types of roofing materials. They are weather resistant and generally retain their looks much better than shingle roofs. Because of the durability and strength of metal, you will replace your roof less often and ultimately save on repair expenses.

Rust, however, is an unavoidable occurrence in all metal roofing. Since most if not all metal roofs have iron contents, rust inevitably appears especially in humid areas since air moisture is a common cause of rust. Rust is, in fact, a typical problem for most Chicago roofing because of the city’s humid climate and extreme weather conditions.

Rust is not only unsightly but also destructive that could lead to more damage if left untreated. If rust develops on your roof, there are steps that you could take to remove them.

Sanding/Brushing

Use sandpaper or steel brush to remove the rust from the surface. Wire brushes can easily scrape off rust and other dirt that accumulated through time. Sanding the area after wire brushing is required if you intend to paint a smooth finish on the roof. For sandpapers, use an 80 grit grade for the initial rough sanding followed by a 120 grit sandpaper for smooth sanding. Be sure to fill in gaps, holes and cracks with filler materials before painting to avoid those rough surfaces.

Acid Chemical

Acid easily removes rust from metal. One pound of oxalic acid to a gallon of water will do the job. Load the acid solution into a spray container and spray the affected areas with hose. Let it sit for a while before rinsing with water until the acid mixture is washed away. Any sign of rust left could be removed with wire brush.

Sandblasting

This is probably the quickest and easiest way to get rid of rust from metal. Sandblasting is the process of cleaning a surface by bombarding it with fine materials at high-velocity. Sand is the most common material used for sandblasting, but other materials are also available. You will need an air compressor for this task aside from the blaster nozzle and abrasive.

Rust Converters

These are products that convert rust into a harmless chemical compound. They also coat the surface with protective film that prevents rust from setting in. Sanding or wire brushing the rusty areas is not necessary before applying a rust converter. No preparation is necessary before the product is used to remove rust. Just apply it wherever rust is found, and it will neutralize rust.

Rust is a perennial problem for structures with iron roofs. All metals containing iron are susceptible to rust when exposed to air and water. Rust is actually a kind of corrosion that applies specifically to metals with iron content. Roof damage is always the result of rust.

It is advisable to keep a regular inspection of your roof as well as conduct periodic repair and recoating with paint and primer if necessary. A metal roof that is not properly maintained has a significantly shortened lifespan. Rust has several effects on metals, all of which are not good.

Rust Produces Holes on Sheet Metal

You often see the effect of rust on metal through bodies of poorly-maintained and junked cars showing patches of holes eaten by rust. The same effect can be seen on roofs. Should you fail to properly protect your roof by scraping off rusted metal and coating the roof with paint, your roof will develop holes. Holes are the passageway through which rainwater goes inside the house. If left untreated, water could ultimately damage the integrity of the whole structure.

Rust Weakens Metal Objects

Rust is usually seen as an orange powder on the surface of corroding metals. Rust, in fact, replaces the strong steel or iron with this flakey powder. Since rust has considerably less mechanical strength than the iron or steel that it replaced, it weakens the whole object. As a result, the strength of the entire object is compromised by the presence of rust. A roof weakened by rust in turn affects the whole structure on which it is a part of, thereby weakening the whole building.

Rust Expands Affected Parts

Rust possesses more volume than iron such that its formation on the affected area will push away adjacent or adjoining parts. This development, called rust-smacking, renders structures susceptible to damage caused by gravity, impact, movement and the weather. A whole bridge in Pennsylvania collapsed from this process when its bolts on the central base were heavily corroded by rust.

Metals Become Stuck When Rust Occurs

It becomes harder for two sliding metal parts to interact with one another because of the presence of rust. The basic examples of this are rusty nut and bolt. The more rust there is the harder it is to turn the nut around the bolt. Applying strong force on the rusty metal object could potentially damage it and render it unusable. Always observe caution when repairing metal roofs with rusty bolts and nails. You may inadvertently create holes and cracks by forcibly separating rusted parts.