Tar roofs generally require replacing as opposed to repairs, because most do-it-yourself patches are just temporary fixes that will endure for a few months, as opposed to a decade. A temporary repair may get you time to prepare financially for a new roof or to employ a specialist with the required equipment to complete a longer-lasting repair. A temporary fix is also preferable to enabling water to damage the roof.
Burst the Bubble
The area where damage has occurred on a tar roof bubbles up or lifts away from the roof. There may nevertheless be water puddled on top of the damaged area. The first step is to sweep the water away, remove the gravel and set it aside, then open the bubbled area with a utility knife or razor blade by cutting an “X” across the center.
Wash and Dry
Lift the flaps of this “X” up so that air may circulate to the bottom layers. Wipe away as much moisture and dirt as possible. Allow the damaged region air dry until all the moisture is eliminated. Wash any remaining dirt or debris from the region. The patch will not stick to a surface that is moist. It adheres better to a tidy roof which isn’t covered in a layer of dirt.
Spread a layer of tar on the roof beneath the spot you have cut away. Press the flaps from the cut portion into the tar and subsequently spread another layer of tar on top of the flaps. Push the tar from this layer out a bit farther so that it goes about six inches past the ends of the cut. Then press a sheet of cotton fabric into the nest till it’s completely saturated with pitch. Add another layer of tar and distribute it out past the edges of the fabric.
Feather the edges of the tar nicely past the ends of the fabric, smoothing it out so that it blends with and adheres to the surrounding tar surface. Eliminate additional gravel is necessary and set it aside to add tar as required. Gently replace the gravel by hand, taking care to cover every area of the patch. Do not use tools to push back the gravel into place, as you could loosen the patch. When working on a roof function safely, put on a hat to protect against sun exposure and wear a safety harness, if necessary, to protect against drops.