Metal roofing systems make for great commercial roofing solutions, but even the best metal roofing can fall prey to rust over time.
If your metal roof develops rust, you’re most likely to get rid of it by hiring a commercial roofing contractor to do the repair, but there are also ways to fight rust yourself. Whether you hire a commercial roofing contractor or do it yourself, rust repair usually has two fundamental steps:
1. Remove the Rust
Before you do anything else, you need to get the existing rust off your roof, at least as much as you can. A low-pressure sand blaster or a high-pressure power washer can usually knock off plenty of the loose flakes of rust on your roof, and you can get more stubborn rust spots off with Trisodium Phosphate.
It’s possible to rent this equipment and clean off the rust yourself, but it can also be dangerous if you’re not sure what your doing, and you may not know how much rust you have to remove. If you’re willing to choose a professional for at least part of the process, this is the point where you should.
2. Coat Your Roof
Just removing rust from your metal roof won’t do much good. You also have to keep it from coming back in a few months. Coating the metal is a great way to keep your roof safe from the encroachment of rust. Usually this involves painting your roof or applying a waterproof coating.
Before you start painting, wash and rinse the roof and give it time to dry. If you’re using paint, put down a zinc primer to cut down on rust, and use metal roof paint for the top coat. The downside of this solution is that you’ll need to repaint your roof every few years to keep rust from coming back anyway.
It may be more desirable to use acrylic coating. Your roof will still look like metal, but roof rust won’t return for up to 10 years.
A professional will do the best job in eliminating rust and preventing it from coming back, but even if you prefer to maintain your roof yourself, always stay on top of rust formation. Great references here.