Asphalt shingle blisters are one of the most common roofing problems, and are often been mistaken for hail damage. In today’s post, local roof repair and installation company State Roofing shares insight on what causes asphalt shingle blisters, and what can be done to fix them.
What Causes Asphalt Shingle Blisters?
Asphalt shingles are made of two layers: the backing material and the outer layer of granules. During manufacture, large rolls of the backing material are fed through rollers and soaked in hot asphalt. The backing material can be made of recycled paper (“organic” shingles), or fiberglass (“composition” shingles). After soaking, a layer of granules are embedded on one side of the uncut, asphalt-soaked material. The granules add color, UV protection and other features like algae resistance. The shingles are then cooled, cut to size and packed.
Variations in temperature and humidity during manufacture can result in moisture getting trapped between the asphalt and granule layers. It may remain trapped even after installation. When exposed to a heat source, such as sunlight or a poorly-ventilated attic, these pockets of moisture expand and form blisters.
Can Asphalt Shingle Blisters Be Fixed?
The good news is, the newer your roof, the less likely it will form blisters. Roofing manufacturers have been implementing stricter quality measures, including controlling humidity levels in their factories, which helps prevent moisture getting between the backing material and granules. However, even with such strict quality control, some asphalt shingles with moisture in them may still make their way to roofs. Since these are considered manufacturing defects, your roofing warranty should cover replacement.
Blisters look very similar to the kind of damage caused by hail, and sometimes even insurance inspectors may mistake one for the other. Differentiating between the two is important, since insurance providers generally consider asphalt shingle blisters as cosmetic damage, while hail damage isn’t. This is why you need to conduct regular roofing inspections. If you notice blisters on your roof, call your roofing contractor for a thorough roofing inspection.
State Roofing is your leading provider of decks and roofing installation services. Give us a call at (360) 794-7164. You can also fill out our contact form to schedule an appointment. We serve customers in Tacoma, Bothell and Everett, WA.