Should You Use Roofing Tar to Fix a Leak in Your Asphalt Roof?

If you've noticed that your asphalt roof is leaking, it's important to fix the leak as soon as possible. Even a small amount of water leaking through a roof can cause severe damage since it can lead to mold growth or your structural decking rotting away.

One way to stop an asphalt roof from leaking is to apply roofing tar to the damaged areas. Unfortunately, this is almost never a good choice for roofing repair—it won't last as long as replacing damaged areas of your roof, and using roofing tar will also make any future repairs more complicated for a contractor to perform. To learn more about roofing tar and why you shouldn't use it to stop your asphalt roof from leaking, read on.

What Is Roofing Tar?

Roofing tar is made of coal tar that's liquefied with a solvent. You apply it to any damaged areas of your roof using a silicone mop. As the solvent evaporates, the roofing tar will cure and harden onto your roof. Since roofing tar is waterproof, you're able to stop your roof from leaking by applying it to torn shingles or damaged flashing on your roof. As long as you cover all of the damaged areas, your roof will shed water normally again. However, it's rarely the best choice for asphalt roofing repair.

Why Is Roofing Tar a Poor Choice to Repair Leaks?

The main problem with using roofing tar to repair an asphalt roof is that applying roofing tar to a sloped roof is challenging. While it's still liquefied, roofing tar flows very easily. When you mop it onto damaged areas of your roof, the tar will begin to flow downhill onto adjacent shingles. Once the roofing tar cures, it will glue strips of shingles together. If any of these shingles are damaged, a roofing contractor will need to remove all of the adhered shingles in order to replace the damaged one. As a result, using roofing tar on your asphalt roof will make future roofing repairs more involved.

Additionally, roofing tar doesn't last forever. Sunlight will cause it to degrade, and it eventually turns dry and brittle. Cracks will form in the roofing tar, and water can easily penetrate through these cracks. Since the roof underneath the tar was never properly repaired, your roof will begin to leak again as soon as the roofing tar begins to break down. This means that roofing tar isn't a long-lived solution to fix roof leaks.

What Should You Do Instead of Asphalt Roofing Repair?

If your asphalt roof is leaking, the best approach is always to have it fixed by a roofing repair contractor. Any shingles that are torn or missing need to be replaced, and any damaged flashing needs to be replaced and re-caulked as well.

Using roofing tar to stop your asphalt roof from leaking is a less expensive solution in the short term than hiring a professional roofing repair company. However, roofing tar will make future repairs more expensive—more work needs to be performed in order to remove all of the shingles and flashing that have tar stuck to them. Ultimately, you'll save money over the long term by having the leak fixed correctly by a roofing repair contractor.