Which term refers to raised areas or bubbles that may appear on the surface of asphalt roofing after installation?

• A. Blisters
• B. Bundle
• C. Buckling
• D. Caulk

Answer: (A)

Raised areas or bubbles on an asphalt roof surface after installation are called blisters. They form when air or moisture gets trapped beneath the asphalt layer or between layers and, as the roof heats up, those pockets push the surface upward into a bubble. This can happen if the deck was damp, if shingles were installed in moist conditions, or if there isn’t proper bonding at edges and fasteners, allowing pockets to lift under heat and sun. Blisters can weaken the roof since water can eventually find its way into the underlayment or nail line, so addressing the cause—dry decking, allowing shingles to acclimate to temperature, and ensuring proper installation and ventilation—is important to prevent future leaks.

Other terms: buckling is a wave-like distortion of shingles from substrate movement or improper nailing, not a localized bubble. A bundle is just a grouping of shingles in packaging, and caulk is sealant used around penetrations or joints, not a surface blister.