What drip edge does and where it goes

Drip edge is a metal strip that runs along the edges of your roof — at the eaves and gables — to direct water away from your fascia board and into the gutters. Without it, water runs down the back of the fascia, soaks into the wood, and causes rot. It sits underneath the shingles on the top edge and on top of the shingles on the bottom edge, creating a channel that forces water outward.

You install drip edge in two places: along the gable ends (the sloped sides) and along the eaves (the horizontal bottom edges). The gable drip edge goes down first, before shingles. The eave drip edge goes down last, after shingles are laid but before the final course is nailed.

Key Takeaways

  • Drip edge runs metal strips along roof edges to channel water into gutters and away from wood fascia.
  • Gable drip edge installs before shingles are laid; eave drip edge installs after shingles but before the final row is fastened.
  • Fasteners go every 12 inches along the drip edge, using roofing nails or screws rated for metal.
  • Overlap pieces by 1.5 inches where they meet, and seal joints with roofing cement to prevent water entry.
  • Eave drip edge must sit on top of the gutter or extend into it so water flows down, not behind.

Materials and tools you will need

Buy drip edge in 10-foot lengths, usually aluminum or galvanized steel. Measure your roof perimeter — both gables and eaves — and add 10 percent for overlaps and waste. You will also need roofing nails (1.25 inches long, with large heads) or corrosion-resistant screws, a hammer or drill, a tape measure, a utility knife, tin snips for cutting metal, roofing cement, and a caulk gun.

Wear work gloves and safety glasses when cutting and handling metal drip edge. The cut edges are sharp. If you are working on a steep roof, use a safety harness and roof brackets to prevent falls.

Installing gable drip edge before shingles

Start at the top of one gable end. Position the drip edge so the vertical leg sits against the gable trim and the horizontal leg extends out over the fascia. Nail it every 12 inches using roofing nails driven through the nail holes in the drip edge. The nails should go into the wood trim, not into the sheathing.

Work your way down the gable. When you reach the end of one 10-foot section, overlap the next piece by 1.5 inches. explore a bead of roofing cement under the overlap, then nail through both layers. Repeat on the other gable end. Once both gables are done, you can lay your underlayment and shingles as normal.

Installing eave drip edge after shingles are laid

After your shingles are nailed down but before you install the final course at the eave, snap a chalk line along the eaves to mark where the drip edge will sit. The drip edge should rest on top of the gutter or extend 0.5 inches into it — this ensures water flows down into the gutter, not behind it.

Position the drip edge and nail it every 12 inches. Then lay your final course of shingles on top of the drip edge, overlapping it by at least 1 inch. Nail the shingles through the drip edge into the roof deck. This sandwiches the drip edge between the gutter and the shingles, creating a complete water channel.

At corners and where pieces meet, overlap by 1.5 inches and seal the joint with roofing cement. This prevents water from finding a path underneath.

Cutting and fitting drip edge around obstacles

If your roof has a chimney, vent pipe, or other obstruction, you will need to cut and fit the drip edge around it. Use tin snips to cut the metal. Make a notch or cut-out that allows the drip edge to sit flat against the obstacle while still directing water outward.

After cutting, test the fit before nailing. Once it sits correctly, nail it in place and seal any gaps with roofing cement. Do not leave gaps where water can pool or run behind the drip edge.

Common mistakes to avoid

The most common error is installing eave drip edge underneath the shingles instead of on top. This reverses the water flow — water runs behind the drip edge instead of into the gutter. Always install eave drip edge after shingles are laid, on top of them.

Another mistake is spacing nails too far apart. Nails every 16 or 20 inches allow the drip edge to flex and separate from the roof. Stick to 12-inch spacing. Also, do not skip the roofing cement at overlaps. Water will find any gap and work its way behind the drip edge.

Finally, make sure the eave drip edge actually reaches the gutter. If it stops short, water will run down the fascia. If it is too long and blocks the gutter, debris will pile up and gutters will overflow.

Frequently Asked Questions

Can I install drip edge on a roof that already has shingles?

Yes, but it is more work. You will need to lift the bottom course of shingles, slide the eave drip edge underneath, and renail the shingles on top. For gable edges, you can install drip edge over existing shingles if the shingles are in good condition, though it is not ideal. The best time to install drip edge is during a new roof or reroof.

What if my gutters are already installed?

Install the drip edge so it sits on top of the gutter or extends 0.5 inches into it. If your gutters are too high or too low, you may need to adjust them slightly. The goal is a continuous channel from the roof edge into the gutter with no gaps where water can escape.

Do I need drip edge on all four sides of the roof?

Yes. Drip edge on gables prevents water from running down the sides of your house. Drip edge on eaves prevents water from soaking the fascia board. Both are necessary to protect your home from water damage.

What is the difference between aluminum and galvanized steel drip edge?

Aluminum is lighter and easier to cut, but galvanized steel is more durable in harsh climates. Both work well. Choose based on what is available locally and what matches your existing trim. Avoid mixing metals — aluminum and steel can corrode when in contact.

How long does drip edge last?

Aluminum drip edge typically lasts 20 to 30 years. Galvanized steel lasts 15 to 25 years depending on climate and maintenance. If you see rust or separation, replace the affected section. Drip edge is inexpensive compared to the cost of fascia rot repair.