With their thick galvanized or Galvalume coatings and a layer of paint on top, modern metal roofing panels are very resistant to rust. However, you'll still sometimes see rust forming on a metal roof. Why does this happen?
The reason for this usually has to do with the fact that fasteners and flashings don't have as much rust resistance as the panels themselves — they begin to rust first, and then the rust spreads from there. Thankfully, the rust can be eliminated and prevented from spreading by a roofing repair professional. To learn more about why metal roofs start to rust and how a roofing repair contractor fixes them, read on.
Where Can Rust Form on Metal Roofing?
The most common place for rust to start forming on a metal roof is around the fasteners. Exposed fastener metal roofing uses numerous metal screws to join adjacent panels together and secure them to your home. They're constantly subjected to wind and rain. However, even standing seam metal roofs use fasteners around the flashings and on trim pieces, so they're not immune to this problem.
Fasteners are commonly made of unpainted galvanized steel. The galvanized layer is thinner, which doesn't give them as much rust resistance as the metal panels of your roof. This is especially true in coastal areas where the fasteners are continually exposed to wind-blown sea spray since it causes the galvanized layer to degrade quickly. Metal flashings on your roof share the same problem.
In some cases, rust can also begin forming on the roof panels. This usually happens when debris carried by very strong winds smashes against a roofing panel, which causes a scratch in the finish. It doesn't take long for rust to form in the exposed area. However, this is a rare occurrence — fasteners and flashings are usually where rust starts to spread.
How Does a Roofing Repair Contractor Fix a Rusted Metal Roof?
If a fastener starts rusting, the best course of action is to have them all removed and replaced. Once one starts to rust, it's a sign that the others have started to deteriorate as well. Removing and replacing all of them at once will help prevent your rust problem from returning. The same concept applies to the flashings on your roof.
Next, any rusted metal panels need to be replaced. This includes any panels where the rust has spread and any ones that have become damaged or are developing rust.
Replacing the panels is a simple task on an exposed fastener metal roof, as they can be easily removed by taking out the fasteners. On a standing seam metal roof, the seams need to be mechanically broken and resealed. Thankfully, most residential metal roofing uses exposed fasteners, so the repair is often quick and easy.
The most important thing you can do when you notice rust on your metal roof is to call a roofing repair contractor as soon as possible. This makes the job less involved. The rust won't have as much time to spread, which means that your roofing contractor won't have to replace as many panels.
Contact a company like Ray's Harford Home Improvement Contractors Inc today for more information and assistance.