Preventing And Treating Rust Problems On A Metal Roof

Metal roofing, obviously, is not supposed to rust – if it were made from rust-prone materials, you'd  be in trouble the first time it rained. So if you have reddish stains appearing on your metal roof, it means that something has gone wrong. What are the most common causes of rust on a roof – and how can they be prevented and fixed?

Worn Rust-Resistant Coating

Most metal roofing is protected from rust by a layer of sealant; some other metal roofing is protected by a galvanized coating. Galvanized coatings usually last longer than sealant, but this can vary based on the quality of the sealant used. Looking at the length of your roof's warranty will give you a sense of how long the manufacturer expects their coating to last. Sealant can also be damaged during heavy storms if branches or large hail impacts your roof – look for areas of flaking after severe weather.

If you're reaching the end of that warranty or are past it, you may see signs of rust start to appear on your roof. When this happens, you need to scrape away the rust (using a wire brush and then sandpaper) and apply a new coating to the roof. If you've waited for a while and the rusty areas are extensive, have your roof checked by a professional to make sure that the structure of the metal panels or shingles hasn't been compromised.

To prevent this from happening, you can proactively restore the galvanization or sealant on the roof. Doing this when your warranty is nearly over is a good idea; alternatively, you can be vigilant for signs of rust. At the first appearance of it, scrape off the rust and recoat the roof. Caught early like this, there should be no lingering damage to the roof.

Rusty Fasteners

The fasteners on a metal roof are sometimes separated slightly from the actual metal by neoprene washers. This is because some metals, when they come in contact with each other, will cause corrosion. If you've got rust on your fasteners, problems with these washers are likely the culprit. High winds during a storm can also cause slight shifts in metal panels that cause them to come into contact with their fasteners.

Luckily, fixing this is usually simple – you just need to replace the washers and fasteners on the roof. If the problem is with the metal panel's shape, however, you'll need to have it bent back into shape or replaced.

To prevent this problem, ask a roofer whether the fasteners in your roof and the roof itself are made from metals that corrode when in contact. If they are, consider replacing them with a material that won't corrode if it comes in contact with your roof; your choices will vary depending on the type of roofing you have. Also be sure to inspect your roof after storms with high winds and check for damage to panels or washers.

For professional roofing services, contact a company such as Palmer Roofing.


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