We have found that many homes with newer asphalt composition shingles installed, are experiencing problems in three major areas. . . Much confusion appears to exist as to what to look for, and what really constitutes a significant defect. I hope the following information is useful in helping shed light on this issue. WHAT TO LOOK FOR. . . . While the cracks may not extend fully through the tabs and the roof may not be experiencing any active leakage now, this type of premature cracking can lead to shortened shingle life.
Typical blisters can range from pea-size up to the size of a quarter, or even larger.
Some blistering on shingles can be due to things like improper ventilation, etc. Shingles that have open blisters in which the asphalt becomes visible, are at greater risk of premature failure. Even small areas of gravel loss can put your shingles at risk of premature failure due to UV penetration, and subsequent deterioration of the asphalt layer. Cracking through the reinforcement, and granule loss that exposes the asphalt layer are serious shingle defects. . . The decorative appliqu layer is bonded to the reinforcement layer underneath.