Shingle Blistering

Found this yesterday. Looks like blistering to me. Area pictured is void of roof ventilation (soffit vents but no gable, ridge or passive vents). Shingle brand is Tamko-Frederick 2446.

roof shingle.jpg

Yep! That is what it looks like to me also.

yep, me too. How well was the attic ventilated?

Man, a lot of those reviews (in Marcel’s link) sound like they were written by the same person.

This was an L-shaped ranch. The “L” portion (or wing) contained the master bedroom and bath and the only ventilation was soffit vents (no gable, ridge, or passiive vents). Also, most of the soffit vents thoughout the attic were blocked by insulation (no baffles).

Excessive heat from poor ventilation is probably the culprit. More likely to happen within the first few years after installation, then stabilize.