How To Repair A Steel Roof

Steel roofs are meant to last, and longevity is one reason why the roofing material is often used on barns, garages, warehouses, and commercial buildings. Many homes now have metal roofs too, and the more inexpensive varieties have exposed seams. These seams can form rust, and the oxidation typically starts on and around the screws that hold the seams together. If you see rust around the screws, then you can repair the problem. Keep reading to learn about some tips that will help you do this. 

Remove Screws And Rust First

Rust forms when iron oxide builds on the exterior of an iron-based metal, like steel. Oxidation is always building as steel is exposed to air, but the rust-forming process is usually quite slow. However, when water comes into contact with the metal, rust builds much more quickly. Rust starts to show up when the iron loses electrons to the oxygen in the air. The makeup of the steel turns to iron oxide, which is extremely weak. While rust does not spread, it often looks like it does. Typically, this happens because one area of your roof will become wet and oxidation will build all along the wet section over time. Also, steel roofs are covered with a protective coating of paint. As rust forms, it flakes off. This can damage the protective coating and leave even more of the steel exposed. 

To keep oxidation as contained as possible, remove the rusted screws and any rust you see around the perimeter of the fasteners. Screws can be replaced fairly easily. You will need to purchase steel hex head screws. Locate screws for exterior applications. If possible, look for fasteners made specifically for steel roofs. To reduce future rust concerns, purchase screws that are painted or coated. Roofing screws will have a baked-on enamel coating that is similar to steel roofing panels. Choose the color that closely matches your roof coating.

Remove old screws, but do not replace them yet. Use a wire brush to remove loose oxidation near the screw hole and then sand the area with a coarse piece of 60- or 80-grit sandpaper. Sand until all rust is released and you see silver steel in the region. The plain steel must be protected from oxygen and water, or new oxidation will develop. Purchase a small tin of enamel paint with a rust inhibitor from your local home store. Try to match the color of your steel roof and use a paintbrush to add the paint to small areas. Use a roller to paint larger spaces.

Repair Holes

Once you have sanded and painted rusted areas, inspect for large holes or gaps in the steel caused by rust. If you do not see any holes, then you can secure the new screws and the repair will be complete. However, if there are gaps in the steel, then you will need to fill them in, or a leak may develop. Purchase some urethane roofing cement or a polyether sealant and some steel mesh to fix the holes. If holes are small and less than the size of a quarter, then place the tube of urethane roofing cement in a caulk gun. Force the caulk into the hole and use a putty knife to smooth it out. Wait a day or two for the cement to cure and use a fine grit piece of sandpaper to smooth out the surface. 

If holes are bigger than a quarter, then you will need to use mesh to fix the roof. Cut a piece of the steel mesh so it is about one-quarter inch larger than the opening on each edge. Place a thin layer of your roofing cement around the hole and place the piece of mesh over the sealant. Press down on the edge of the mesh to secure the material in place. Squeeze a generous amount of the cement in the middle of the steel mesh and use your putty knife to smooth it out over the material. Taper or angle the sealant around the sides of the mesh so the urethane sits flush with the surrounding steel. Let the sealant dry and then sand the cement to smooth it. 

If you need help with your roof repair, contact a company like Stevens Roofing Corporation for assistance.

Share