Why Do Asphalt Shingles Blister?

Blistering is a common problem with asphalt shingles. It’s usually caused by either these two things: trapped moisture in the shingles or poor roof ventilation. Nevertheless, blistered shingles generally do not pose any immediate risk to your residential roofing. They won’t impact the performance and longevity of your roof. But it’s worth keeping in mind that shingle blisters pop after some time. When this happens, the materials underneath the shingles will be exposed to the sun’s heat and UV rays.

In this post, trusted roofing company STARR Roofing & Gutters discusses the common causes of shingle blisters. We also share some tips on how you can prevent shingles from blistering and how to keep shingle blisters from popping.

What Causes Asphalt Shingles to Blister?

As mentioned earlier, moisture and poor roof ventilation are usually the culprits that cause blistered shingles. Here’s how blisters develop in these conditions:

Trapped Moisture

Moisture can get trapped within the shingle during the manufacturing process. So once the shingle has been installed and the sun beats down on your roof, all the trapped moisture will naturally heat up as well. This causes the blisters to rise up on the shingles.

Poor Roof Ventilation

Roofs with no proper ventilation can become too hot for the shingles. This intense heat can cause the shingles to blister over time.

When Should I Be Concerned About Blistered Shingles?

In general, blisters shouldn’t be a cause for concern as long as the granules on your shingles are intact. But as discussed earlier, blisters will eventually pop and this is when you should keep an eye out for damage. Typically, when blisters pop, the shingle granules also become dislodged. This leaves the roofing material vulnerable to potential damage from the UV rays of the sun. Furthermore, your roof will be more prone to losing more granules.

How Can I Keep Shingle Blisters From Popping?

While the blisters are known to pop eventually, blistered shingles are not a completely hopeless case. Here are some tips on how you can prevent shingle blisters from popping:

• During roof maintenance, be careful not to step or walk on the blistered shingles. Blistered shingles can easily pop when they are stepped on.
• Watch out for falling debris, especially if your home is surrounded by trees that could drop limbs, acorns, pine cones or other types of debris onto your roof. These objects can cause shingle blisters to pop. So if possible, choose to remove the trees that could potentially cause damage to your roofing.
• Hail storms can also cause blisters to pop. While there is nothing that you can do to prevent hail from hitting your roof, you can opt to act quickly and have a contractor check on your roof after the storm. Roof inspections allow you to detect problems early and perform necessary repairs before the damage gets worse.
• You can replace the blistered shingles even before they pop. This may be a costlier option depending on the number of affected shingles.

How Can I Prevent Shingles From Blistering?

Here are a few simple ways that will help you avoid blistering.

Choose Quality Shingles

For a new roof construction or roof replacement, make sure to select asphalt shingles from trusted manufacturers. While the conditions during the manufacturing process are beyond your control, good shingles from reputable manufacturers would at least be durable enough to avoid blister popping. It’s possible for shingle blisters to simply disappear once the vapor contracts or the moisture evaporates, thus avoiding eventual damage to your roof.

Hire a Reputable Contractor

Shoddy installation can affect the quality and performance of your asphalt shingles. That’s why you should always remember to check the qualifications and reputation of the roofer you’re going to hire. Make sure they have the proper training and are experienced in installing asphalt shingles. Otherwise, you shouldn’t entrust your roofing project to them.

Ensure Good Attic Ventilation

Attic ventilation is crucial to your roof’s health. While asphalt roof systems are designed to withstand heat, extreme temperatures can still cause several problems to the roofing material. But if your roof and attic are properly ventilated, you can maintain a steady temperature that won’t be harmful to your roof. Keep in mind that heat is a significant factor in blistering. But if proper venting is included in your roof’s design, you can rest assured that heat won’t build up in the attic and cause problems.

Shingle Blisters Vs. Hail Damage: How Can I Differentiate Them?

In some cases, blister damage and hail damage may look similar, so differentiating them can be difficult. But according to roofing professionals, you can tell them apart by checking the damage pattern on the roof. Typically, roof damage caused by hail has a more uniform appearance, and it can only be found on a particular slope depending on the wind direction during the hail storm. In the case of blistered shingles, the damage is usually uneven since some blisters may already have popped while others remain un-popped.

Of course, it’s still best to leave this job to the experts. With their expertise, they can easily identify the type of damage on your roof. It’s also highly recommended to schedule regular roof inspections and maintenance to keep your roof in good condition. Roof maintenance may seem like an added expense, but it’s an important investment on your part since this will help you avoid more significant roof damage that would cost more to repair. Worse, depending on the extent of damage on your roof, you may even need to replace your roofing. 

Get a Free Quote Today!

STARR Roofing & Gutters is a locally owned and operated roofing company that caters to residential and commercial clients. We specialize in roof installation and repairs, metal roofing, gutters and more. With our team’s professional skills and experience, we can guarantee top-notch workmanship for your project and value for your money. Call us at (512) 736-6539 to get a free quote. You can also fill out our contact form to schedule a consultation.