Drip edge is a metal flashing strip installed along the roof's eaves and rakes that directs water away from the fascia and into the gutters.
Drip edge is a small but important detail — without it, water running off the roof edge can wick back under the shingles or run down the fascia board, leading to rot over time. It's installed under the underlayment at the eaves and over the underlayment at the rakes (the sloped edges), and is required by most modern building codes.
Most current U.S. building codes require drip edge at eaves and rakes on new roofing installations — it's a low-cost component relative to the water damage it prevents.
Get matched with licensed contractors near you.