The Usual Culprits Behind Asphalt Shingle Blisters

Blisters appear on your roof when volatiles (chemical compounds added to asphalt for waterproofing) leak out of asphalt shingles. Since asphalt shingles are made of two layers, blisters won’t immediately cause leaks. However, they can shorten your roof’s lifespan. That’s why roofing shingles with blisters need to be replaced as soon as possible.  

How Blisters Affect Your Shingle Roof’s Lifespan

Some of the granules embedded into your asphalt shingles are dislodged whenever blisters pop. Extensive granule loss is a problem because without them your roof is vulnerable to damage from ultraviolet (UV) rays and premature aging. Premature aging can, in turn, cause cracks to form on your shingle roof and create leaks. 

Important note: keep in mind it’s normal for your shingle roof to lose granules over the course of its service life. That’s why manufacturers embed up to 40% more granules in their asphalt shingles. Granule loss only becomes a problem when it becomes so extensive that bald patches start appearing on your roof or granules start accumulating in your gutters. If you see any of these warning signs, you should start planning a roof replacement. 

What Are the Usual Culprits Behind Shingle Blisters?

• Manufacturer defects – Over time, moisture that was trapped in the shingle substrate during the manufacturing process will evaporate and create pockets of air that will, in turn, create blisters on the surface of your shingle. However, as long as you used shingles from reputable brands, such as Owens Corning®, you shouldn’t worry too much about manufacturer defects.
• Installation errors – Blisters are more likely to form on roofs that were not installed correctly. To prevent installation errors, make sure to vet a prospective roofer before hiring one.
• Poor ventilation – If warm, humid air is unable to exit your roof or attic due to poor ventilation, it’s only a matter of time until blisters – as well as a host of other roofing issues like mold – appear.

Christian Brothers Roofing has been serving the Louisville area since 1997. We offer a wide range of professional roofing services, including roof repair and replacement services. To get a free estimate, call us at (270) 715-1999, or fill out this form.