How to Repair Flat Roof with Damaged Felt?

Most flat roofs are constructed from tar and layers of roofing felt, while other types are made entirely of concrete. You may find leaks on specific spots, usually in low spots or areas with damaged felt. Unlike other roofing types, damages on the flat roof are very easy to detect. If you found the damages, it would be simple to immediately assess it. The first thing to do is to mop up or remove pooled water around the damaged areas, allow the spot to completely dry as the humidity may seep deep inside the roofing construction.
In more serious cases, you’ll see some blisters around the damaged areas, use a large knife to slice those blisters and let any excess water to get drained. When the sun doesn’t shine brightly, get a fan to remove humidity around the area. If you are forced to repair the damages during winter where the water seems to refuse to drain, you may need to use propane torch to heat up the surrounding. Don’t subject the felt to open flame directly as you may create further damages and the tar can be quite flammable when heated too long.
If you believe that the felt is dried sufficiently, apply a good amount of cement on the edges of the damaged or loose felt, the next step is to firmly press the blisters sides down. To finish the job, the blisters can be closed with roofing nails. Re-apply roofing cement on the whole area. In general, the durability of your flat roof is determined by the geographical location, maintenance and material quality. If you think that the scope of the repair job is beyond your capability, contact a skilled professional to do it for you.