How to Repair Rust on a Metal Roof

rust on a metal roof

Metal roofs have quickly become a popular option for homeowners due to their easy installations, durability, and long life spans. However, metal roofs are susceptible to a few unique problems, like rust. Keep reading to learn how to repair and protect your metal roof.


Get the right tools for the job.

The majority of metal roofing materials are made up of galvanized metal or are coated to prevent rust from forming. But standing water and direct sunlight can gradually wear away the roof’s protection.

It’s important to remove rust before it creates any cracks or holes in the roof.

Grab the following tools and materials to remove rust and repair any damaged areas:

  • detergent
  • scrub brush
  • wire brush
  • pressure washer
  • wire brush
  • 80-grit sandpaper
  • rust inhibitor
  • roofing screws
  • paintbrush
  • putty knife
  • metal primer
  • urethane roof cement
  • direct-to-metal roof paint
  • steel roofing mesh
  • tin snips
Having the right tools for the job will make the repair process go much smoother. Keep in mind, however, that scrubbing away rust and repairing a metal roof requires a good deal of tenacity and handiness, so it may be best to hire a contractor for the repair.
 

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Scrub away the rust.

scrub away rust on metal roof

Once you’ve gathered the right tools and materials, it’s time to get scrubbing.

Pro Tip: Because metal roofs can get quite hot in the middle of the day, work on the metal roof either in the morning or in the evening. Wear a safety harness to prevent falls, and always tell someone you’ll be on the roof.
 

Step 1: Wash the rusted areas with detergent and water, making sure to scrub off any mold growth with a scrub brush. This will reveal all the rusted areas while ensuring any repairs you make adhere properly. You can use a pressure washer to expedite the process.

Step 2: If your metal roof has rusted sections, more than likely, the screws used to fasten these sections are also rusted. Pull up any rusted screws and replace them.

Step 3: Use some elbow grease and scrub the surface rust with a wire brush before sanding with 80-grit sandpaper.

Step 4: If your metal roof has large sections of rust, it’s inevitable that you’ll have to repair a few holes and cracks. Using urethane roof cement and steel roofing mesh, spread a layer of cement over the damaged section, making sure to extend at least 1 ½ inches on all sides. Cut a piece of steel roofing mesh to size to cover the area.

Step 5: Add a second layer of cement on top of the mesh. Cut another layer of steel mesh, press it into the first layer and coat with even more cement. Finally, smooth out the final layer to create consistency with the roof.

Step 6: Apply a layer of metal primer to all the areas you repaired.

Step 7: Paint the roof with approved metal roof paint. One of the best options on the market is an acrylic direct-to-metal coating, which works for galvanized steel, tin, and aluminum roofs. They can be applied either by brushing or spraying.


Hire a professional roofing contractor.

As you can see, repairing a rusted metal roof is quite the improvement project. It can be dangerous, is very labor intensive, and requires at least a full day to accomplish.

If you can’t find the time to repair your metal roof yourself, Hometown Roofing Contractors makes it easy to find qualified roofers in your area. See how other customers feel about each company's roofing services and request multiple quotes to ensure you find the right pro for the job.

Find an experienced metal roofing contractor