How long is drip edge, and how long should it be?

The dimensions that matter

Length of the piece is only part of the answer. The shape matters more:

• Roof flange: the part that lies flat on the deck under the underlayment or shingles. It must cover at least 2 inches of deck, and wider flanges give the nails more to grip.
• Face or drop leg: the part that hangs down over the fascia. It must extend at least 1/4 inch below the bottom of the sheathing so water drips clear instead of running back onto wood.
• Drip lip: the small kick at the bottom on D-style edge, which throws water farther from the fascia.

Code requirements in plain terms

The IRC calls for drip edge at the eaves and rake edges of shingle roofs, laps of at least 2 inches where pieces meet, and fasteners no more than 12 inches apart. Underlayment goes over the drip edge at the eaves and under it on the rakes. Georgia's residential code is based on the IRC with state amendments, and your local building department enforces it, so check there if you need the exact edition.

When a drip edge is too short

A face that stops at the bottom of the deck lets water curl back and soak the fascia and deck edge, which shows up as peeling paint and soft wood behind the gutter. Gaps at corners do the same thing. On a replacement, new drip edge across the whole perimeter is the normal approach.

See drip edge explained and gutter sizing and guards for how drip edge and gutters work together.