GAF prefers replacement where possible. Reuse requires checking condition, expected service life and size compatibility with the new shingles; enhanced warranties may require advance approval.
GAF technical bulletin: Re use of metal flashings on asphalt shingle roofs.
What this means for your roof
GAF prefers replacement where possible. Reuse requires checking condition, expected service life and size compatibility with the new shingles; enhanced warranties may require advance approval.
A useful question for your contractor
Ask for each reused flashing detail to be identified and justified in the proposal.
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: Re use of metal flashings on asphalt shingle roofs
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.