Metal roof systems are increasingly gaining popularity in residential buildings in the United States, and for good reasons. They offer great durability since they don’t rot, crack, burn, split, crumble, or break. Today’s metal roofing systems can also be designed to mimic traditional slate, wood shakes, or asphalt shingles, making them more aesthetically appealing. However, metal roofs can still spring leaks due to a variety of reasons. Here are five common reasons your metal roof can leak and how your roofer can fix them:
1. Metal roofing screws
Metal roofing screws are meant to seal water out by pressing a rubber washer at the base of the screw head. Once the screw is driven into the roofing panel, the rubber washer typically acts as a gasket between the screw head and the roofing panel. During the installation of metal roofs, several things could go wrong and cause leaks. For example, over-driven screws, under-driven screws, screws driven at wrong angles, or screws missing the washer could all cause leaks.
It’s always wise to seek the services of an experienced roofing contractor to ensure all roofing screws are properly driven and your metal roof will remain watertight for years to come.
2. Stack flashings
The area around stack flashings on metal roofs is also prone to leaks. Stack flashings are typically “boots” worn around pipes which come through the metal roof. Air vents, HVAC vents, and plumbing pipes all protrude through your metal roof. Stack flashing is what makes these pipes waterproof. Most stack flashings are made of rubber or rubberized materials which sit flat on the metal roof to form a tight seal while at the same time squeezing around the pipe.
Continuous expansion and contraction of metal roofs often test these seals. UV rays can also degrade these flashings over time and cause them to fail before the lifetime of metal roofs. Whenever you notice leaks around pipes, call your roofer to replace rotten or worn stack flashings to keep your home dry.
3. Missing sealants
Roof sealants are usually installed together with metal roofs, but they don’t often last as long as metal roofs do. They’ll need to be replaced through regular maintenance to keep your roof waterproof. Sealants are installed under trims such as flashings, ridge caps, counter flashings, pitch pans, and around roof transitions. They’ll all need to be topped off regularly as they wear. Let your roofer use metal sealants specifically designed for metal roofing systems since silicon caulking may not properly adhere to the paint on roofing panels and trims.
4. Curb Flashings
HVAC systems installed on metal roofs often sit on curbs. However, the process of installing curb flashings requires high expertise to keep the roof waterproof. Rainwater can sit behind the flashing and eventually erode sealants, causing leaks. You need to work with a roofer who has experience working with metal roofs to ensure the flashings will stand the test of time.
5. Seams and overlaps
The area where two pieces of metal roofing sheets overlap each other can often leak because of a capillary draw. This is where water travels uphill between two tightly joined sheets of metal. Butyl tape or sealant can be installed between the two pieces of metal to break the capillary draw. When not correctly installed, these sealants can actually make leaks worse. Have your roofer inspect seams and overlaps on your metal roof and make the necessary resealing.
Ultimately, working with a reliable and skilled roofer who has extensive experience working with metal roofs will ensure your roof remains leak-free for several years. At LB Solutions, LLC, in the Twin Cities (MN), we have a team of skilled roofers who will correctly install your metal roof and also help you take care of it throughout its lifespan. Contact us today for a free estimate!