Posted on: 22 October 2021
A tar roof is most often applied to flat-roofed commercial buildings. It consists of a membrane layer covered by bitumen and gravel, which creates a more durable and waterproof surface. Over time, damage and aging can cause issues with the membrane or bitumen layers, which will lead to the need for repairs. Knowing the symptoms of problems can ensure you schedule a repair before major damages occur.
1. Surface Blisters
Blisters look like bubbles or raised areas on a flat roof surface. They are a result of membrane separate beneath the tar layers of the roof. This can happen due to adhesion failure, but more often the cause is a crack or leak in the roof that allowed water to seep beneath the bitumen and membrane layer. Locating the leak and patching it is necessary.
2. Water Incursion
Leaks are a common sign that you need a roof repair, but if there aren't visible cracks on the roof surface, then the leaks aren't always immediately obvious. Check in the attic and ceiling crawl spaces for signs like wet insulation. Mold and mildew growth in the building is another sign that your roof might have a leak, as well.
3. Standing Water
Water should ideally drain off a flat roof very quickly, either from perimeter drains or via an internal drain system. If water tends to collect on the roof, then damages are very common at the collection point. You can spot standing water issues on tar roofs even when the roof is dry since there will usually be a discolored spot where water collects. The low area needs to be leveled out or a drain must be installed; otherwise, leaks will occur as the standing water weakens the roof materials.
4. Surface Graveling
Tar roofs gravel as they age. Graveling is when the bitumen layer begins to shrink and wear away, allowing the aggregate inside to come loose. This slow erosion process can result in holes and leaks. Resurfacing the roof or applying a sealer are techniques for repairing graveling issues if you catch the problem early.
5. Separated Seams
The membrane beneath the bitumen layer will have seams where the lengths meet. These seams are usually sealed with a painted on sealant, and then the tar covers the whole thing. Over time, the seams can begin to separate and shrink away from each other. This will be obvious as fairly straight cracks in the top bitumen layer will start to form. Resealing the seams and patching the cracks may be necessary.
Contact a commercial building roof repair service to learn more.Share