Concentrated runoff can repeatedly strike a small shingle area. GAF discusses routing downspout discharge appropriately rather than allowing avoidable wear.
GAF technical bulletin: Damage to shingles from gutter and downspout.
What this means for your roof
Concentrated runoff can repeatedly strike a small shingle area. GAF discusses routing downspout discharge appropriately rather than allowing avoidable wear.
A useful question for your contractor
Ask whether an extension can carry water to the receiving gutter without damaging the roof.
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: Damage to shingles from gutter and downspout
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.