Learning how to repair rolled roofing means you can do it yourself if you wish. Bring your junk clothes for this job! Rolled roofing usually expands and contracts with temperature changes, as the building settles, and the roof ages. As this happens, the different layers become wavy, or blisters can develop and crack open. When wavy spots happen along the lower edge of a layer, the layer can pull up and away from the layer underneath. If it pulls up just a tiny bit, that can sometimes be a worse leak source than a bigger wavy spot because capillary action sucks in standing water.
You’ll need a utility knife, tar, a trowel, a roll of fiber roofing fabric, a hammer, roofing nails, and a ladder. WD-40 on your hands or gloves will keep the tar from sticking. In the wavy spots that lead to an edge, slice through the rolled roofing along the highest part of the wave from the flat part to the edge. You will then have two flaps that can be opened up like the letter ‘A’. Dry out any wetness, trowel in some tar, and nail down the flaps. Then put a medium layer of tar on top of the cut, cover with a strip of roofing fabric and push it into the tar till it squishes through the weave. Cover with a thin layer of tar, troweling out to nothing at the edges. Cut blisters open in an ‘X’ pattern and finish the same way.
Look for any raised nailheads. If they pull out easily, put a new nail in next to it, patch with tar and fiber. Clean tar from tools and yourself with gasoline. Repairs could last 2-5 years. Knowing how to repair rolled roofing helps you appreciate the work of the pros