Bundle handling and storage can leave temporary distortion. GAF explains why some shingles settle with appropriate weather exposure
GAF technical bulletin: Shingle bundle distortion.
What this means for your roof
Bundle handling and storage can leave temporary distortion. GAF explains why some shingles settle with appropriate weather exposure. This is different from deck movement, damaged shingles or an installation defect.
A useful question for your contractor
Ask for a documented follow-up rather than an unsupported promise that every wave will disappear.
Ask for the answer to be tied to the actual roof condition and the exact product being installed. Keep the agreed repair or installation detail with your estimate and project photos.
Bulletin revision: February 1, 2021. This is the date of the manufacturer source, not a claim that this website guide existed on that date.
Read GAF: Shingle bundle distortion
This homeowner summary explains the cited bulletin. The complete manufacturer document and current product instructions govern the installation details. A requirement for one manufacturer or product should not be transferred to another without checking.