Way Up on the Roof

If you live downwind of a power plant or factory that's emitting sulfur dioxide or nitrogen dioxide into the air, your area may experience occasional bouts of acid rain. Sulfur dioxide and nitrogen dioxide turn into acid when they mix with moisture in the air, and the acid is carried down with any rain or snow that falls.

When you have a metal roof and live in an area that experiences acid rain, you need to have your roof inspected regularly to make sure it's not being harmed by the acid. Metal roofs are made from painted galvanized steel, which is steel that has a layer of zinc applied to it to help it resist corrosion. Acid rain will eat away at the paint and zinc layer, making the metal roofing panel susceptible to rusting away.

If your metal roof has started rusting because of acid rain, you'll need to have it repaired. To find out how you can fix a metal roof that's been damaged by acid rain, read on.

Locate All of the Acid-Damaged Areas on Your Roof

Acid rain will damage some parts of your roof worse than others. Since the acid is carried with the rain, it causes more damage where rain collects on your roof, such as in valleys between two metal panels. Parts of your roof with a shallow slope are also more susceptible to being damaged by acid rain, as they won't shed water as quickly as the parts of your roof with a steeper slope. To find out which areas are being damaged by acid rain, look for missing paint, visible rust, or etching in the metal surface of the panels.

Repair All of the Corrosion Damage

If the rust hasn't corroded all the way through the metal panel, it can be repaired using a rust remover. Rust remover converts iron oxide (rust) to ferric phosphate, which can be easily brushed off.

When acid rain eats a hole through a metal roofing panel, the hole will need to be patched to prevent your roof from leaking. A hole in a metal roof can be patched by using a saw to cut a square piece of metal that's larger than the hole, then using roofing cement to glue the patch to your roof.

If a metal panel is badly corroded and has multiple holes, however, it will need to be removed and replaced entirely. It's simpler to replace the entire panel instead of cutting and applying multiple patches.

Repaint Your Roof or Apply a Coating to Protect the Metal Panels

Once all of the acid damage on the roof has been fixed, you'll need to protect any steel that no longer has its paint or zinc coating. Even if it's not subjected to any more acid rain, the exposed steel will rust because of humidity in the air. You can either repaint your roof or apply an elastomeric coating to it in order to protect the steel from moisture.

If acid rain is a frequent occurrence in your area, make sure you keep an eye on your metal roof to make sure that it's not becoming corroded. If you notice any signs of rust, call a roof repair service in your area and have the roof inspected. A roof repair service will examine the entire roof, remove any rust that they find, and patch holes in your roof to stop it from leaking.

For more info, contact a roofing service in your area.