Understanding Roof Blistering and How to Address It

What is Roof Blistering?

Roof blistering occurs when pockets of air become trapped between layers of built-up or modified bitumen roof membranes. This issue is common in flat or low-slope roofs and can lead to significant problems if not addressed promptly.

Causes of Blistering

Thermal Expansion

One primary cause of roof blistering is the formation of volatile asphalt gases due to overheating. These gases create lamination voids that expand over time because of thermal contraction and expansion, often exacerbated by water vapor.

Poor Workmanship

Blistering can also result from subpar installation practices, particularly with flat roof membranes. However, with asphalt shingles, poor ventilation below the roof is typically the culprit, causing the roof deck to overheat and trapping gases within the shingles.

Improper Ventilation

Insufficient ventilation prevents shingles from releasing absorbed heat, causing the asphalt to release gases that form blisters. This overheating can damage the roof deck and the shingles, leading to blistering.

Effects of Blistering

Blistering significantly shortens the lifespan of a roof. It stretches and distends the roof, causing protective granules or gravel surfacing to disintegrate. This accelerated UV damage leads to delamination, cracking, and the eventual loss of shingles. Exposed areas can then suffer from further weather damage, especially during rain, storms, or snow.

Addressing Roof Blistering

Regular Inspections

Regular roof inspections can identify early signs of blistering. Look for patches of raised shingles or bubbles on the roof surface. Addressing these issues promptly can prevent more extensive damage.

Professional Repairs

Engage professional roofing contractors to repair blistering. Expert contractors like Advantage Remodeling and Roofing offer superior workmanship and can ensure the job is done correctly, adding value to your property.

Ensuring Proper Ventilation

Ensure your roof has adequate ventilation to allow shingles to release heat effectively. Proper ventilation reduces the risk of blistering and extends the roof’s life.

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