If you notice spots on your asphalt roof when you're cleaning the gutters, you might think your roof has hail damage you didn't know about. However, the real cause might be shingle blisters. Blisters can form on asphalt shingles for different reasons, and the damage is different from that caused by a hail strike. It's a good idea to let a roofing contractor examine your roof to determine what the spots are so repairs can be done if needed. Here are some causes of shingle blisters and what you can do about the problem.

Things That Cause Shingle Blisters

It's possible for shingles to have blisters due to a manufacturing defect or improper installation. If these reasons are to blame, you might notice the spots shortly after your new roof is installed. Unlike a hail strike that leaves a dent in the surface of the shingle, a blister forms from the inside out due to moisture between the layers of the shingle or due to excess roof heat. Your roof can get too hot if the attic has poor ventilation, and that could be a cause of shingle blisters.

What To Do About Shingle Blisters

You'll want a roofing contractor to advise you about repairing a roof with blisters. If moisture or poor attic ventilation is to blame, this has to be fixed before repairs are done to the roof. Then, the contractor decides if the spots are just cosmetic or if they signal damage to the shingles. If the asphalt granules are still intact, your roof might not be damaged. However, the problem is that the granules could fall off the blisters at any time or the blisters could pop. When that happens, you'll need to have repairs done to prevent a leaky roof.

As long as the deck doesn't have moisture damage too, replacing the blistered shingles might be all that's necessary. The blistered shingles might be confined to one side of the roof or in a small area so your entire roof doesn't have to be replaced. By replacing the shingles, you eliminate concerns over the blisters causing leaks in the future, so you might want to go ahead and have the repairs done even if your roof isn't leaking currently.

Another thing to consider is how the blisters affect the appearance of your home when the blisters are visible from the yard or street. The dark spots might make your roof look ugly, worn, or damaged. If you're putting your home on the market, buyers might be leery about a roof with spots even if the spots aren't leaking at the time. You may be unsure about how to deal with shingle blisters, so listen to advice from your roofing contractor, who's probably seen the problem many times and is able to tell the difference between a cosmetic problem and a problem that needs prompt repairs.