Modified bitumen roofs are a popular choice for low-slope roofing because of their durability and weather resistance. However, leaks can sometimes occur around chimney flashing, which is the metal barrier designed to prevent water from seeping in where the chimney meets the roof. These leaks often happen because the flashing can become loose, rusted, or improperly installed. The flexible asphalt layers in modified bitumen can also crack or shrink over time, especially if exposed to extreme temperature changes. A quick DIY check involves looking for visible gaps or cracks where the flashing meets the chimney and roof, inspecting for any soft or damp spots on the ceiling inside, and ensuring the sealant around the flashing looks intact. If your roof warranty is still active, keep records of your inspections and take photos, as these can be helpful when talking with your contractor or insurance.
If you notice persistent water stains or suspect flashing problems, it's important to call a roofing professional, as working around chimneys involves safety risks and requires specialized tools and materials. When you contact a contractor, ask specifically whether they will replace or repair the flashing and if they use compatible materials to maintain the modified bitumen’s waterproof integrity. Also, inquire about what warranties they offer on both labor and materials. Being mindful of these points can help you avoid future leaks and protect your home effectively without jeopardizing your roof’s coverage or structural health.