What amount of shingle overhang on a rake side is acceptable?
A 2” overhang for shingles is excessive. Always follow the manufacturers installation instructions, because 1) performance is limited, 2) longevity is limited, and 3) warranty is voided.

shingles will sag and bend over time. This can create problems elsewhere, like tearing the underlayment, etc.

Shingles will wear out quicker because the shingles will fold at the roof line.

If you file a claim after a few years, a manufacturer’s representative will visit the site and void the claim. (If pieces of shingle blow off and break your neighbors windows, you’re liable.)


I find that when obvious things are done improperly, then other things are often done improperly too. I’d check the number of nails used per shingle, placement of nails from the top of the shingle, distance of first nail from edge of shingle, exposure of shingles, etc.
Btw, check several places on all sections of the roof. One roofer might do a great job where he’s working, but his assistant might be terrible.