Asphalt roofs can blister and so can built-up-roofing. These blisters are often mistaken for hail damage or other small structural damage. In this article we will only be discussing blistering on asphalt roofs.
When you see blistering on your roof, it may be cause for concern, but it’s rarely cause for alarm. In this brief piece, we’re going to learn what causes roof blistering, and what you should do – if anything – when you see blisters on your roof.
What causes asphalt shingles to blister
Blisters are typically caused by one of two things.
The first is some kind of defect in the manufacturing process. These defects are now quite rare because all of the measuring and mixing is handled by computers. Nonetheless, it can happen. In these circumstances, gasses caused by excessive moisture or other manufacturing defects would eventually bubble to the surface of your asphalt shingles, causing blisters.
Nowadays, these types of blisters are uncommon, but the second type of blister – caused by heat – is still incredibly common.
Heat-induced blisters are created when volatile organic compounds (VOCs) blast out of the asphalt as a result of excessive heating. Poor attic ventilation is a major cause of these types of blisters. They’ll typically appear within the first year of asphalt shingles being installed.
What should I do about blisters on my roof?
Now that you know what blisters are, the next step is repairing the affected shingles – or leaving them alone!
When you have a few small blisters on your roof, it’s nothing to worry about. Simply monitor them – if they start getting bigger, or you see more and more blisters, you’ll want to call for repairs or shingle replacement.
Large blisters can cause a number of problems. They can compromise the protective barrier your shingles provide, allowing water to leak into your attic. They’re also just plain ugly – houses with blisters and holes all over the roof don’t exactly fetch the highest price on the market.
That means if you’re worried about the integrity of your roof – or if you’re just concerned about how it looks – you should give us a call. We can inspect your roof, determine whether the damage was caused by blisters or something else, and repair what needs to be fixed.
We can also evaluate your roof’s insulation, and determine whether or not better insulation could help prevent blisters from forming in the future.