How to Install a Drip Edge
How to Install a Drip Edge
A drip edge is a simple but critical piece of metal flashing installed along the eaves and rakes (sloped edges) of a roof. It directs water away from the fascia board and into the gutter, preventing rot, water damage to the decking, and pest entry. Since 2012, the International Residential Code (IRC) has required drip edge on all new roofs and re-roofing projects in jurisdictions that adopt the IRC. Even where not required by code, it is one of the best investments you can make in your roof's longevity.
Estimated time: 2-4 hours for an average home
Estimated cost: $1-$2 per linear foot for material (aluminum or galvanized steel); $75-$300 total materials for most homes; professional installation adds $200-$400 in labor
What Does a Drip Edge Do?
Without a drip edge, water flowing off the shingles wraps around the edge of the decking by capillary action, soaking the fascia board, soffit, and sheathing edge. Over time, this causes:
- Fascia rot -- the board behind the gutter deteriorates and gutters pull away
- Deck edge rot -- the plywood or OSB sheathing delaminates along the eaves
- Pest entry -- gaps between the sheathing edge and fascia allow insects, birds, and rodents into the attic
- Ice dam damage -- water backing up under shingles has a direct path into the structure when no drip edge is present. See How to Prevent and Remove Ice Dams.
A properly installed drip edge creates a clean break between the roof surface and the gutter, ensuring all water drops into the gutter channel or falls free of the fascia.
Types of Drip Edge
Type C / Type D (L-Shaped)
- Shape: Simple L-shaped profile -- one leg lies on the deck surface, the other hangs over the fascia
- Use: Eaves (the horizontal bottom edges of the roof)
- Common dimensions: 1-1/2 inch deck leg, 1-1/2 inch fascia leg
- Also called: "L-drip" or "standard drip edge"
- Best for: Roofs with gutters, where you only need to direct water off the deck edge into the gutter
Type F (T-Shaped)
- Shape: A more complex profile with an extended lower flange that kicks water outward
- Use: Rakes (the sloped side edges of the roof) and sometimes eaves on homes without gutters
- Common dimensions: Varies, but typically a 2-3 inch deck leg, a 1-inch return bend, and a 2-inch fascia leg
- Also called: "F-style drip edge" or "gutter apron"
- Best for: Rake edges where wind can drive rain sideways under the shingle edge; also provides a more finished appearance
Choosing Material
- Aluminum: Lightweight, rust-proof, easy to cut, available in many colors. Most common choice for residential roofing.
- Galvanized steel: Stronger than aluminum, good for high-wind areas. Will eventually rust if the galvanized coating is scratched or wears through. Heavier and slightly harder to cut.
- Copper: Premium material, long-lasting, develops a natural patina. Expensive and rarely necessary for a standard drip edge application.
Match the color to your roof, fascia, or gutters for the best appearance. Most suppliers carry white, brown, black, and a few other standard colors.
What You'll Need
Tools
- Tin snips (aviation snips -- get left-cut and right-cut for versatility)
- Hammer
- Tape measure
- Chalk line (for alignment on long runs)
- Utility knife
- Pry bar (if removing old drip edge or lifting existing shingles)
- Caulk gun
Materials
- Drip edge sections (sold in 10-foot lengths -- measure total eave and rake length, add 10% for overlaps and waste)
- Roofing nails (1-1/4 inch galvanized, for nailing into the deck)
- Roofing sealant (for sealing overlaps and end cuts)
- Underlayment (if installing during a re-roof -- the drip edge installation order depends on underlayment placement)
Critical Installation Order
The most important thing to understand about drip edge installation is the relationship between drip edge and underlayment. Getting this wrong allows water to bypass the drip edge entirely.
- At the eaves (bottom edge): Drip edge goes UNDER the underlayment. Water that penetrates the shingles hits the underlayment and flows down to the drip edge, which carries it into the gutter.
- At the rakes (side edges): Drip edge goes OVER the underlayment. This prevents wind-driven rain from getting under the underlayment at the roof edge.
This means you install eave drip edge first, then underlayment, then rake drip edge. This order is specified in the IRC building code and most shingle manufacturer installation instructions. See Roofing Building Codes and Permits.
Step-by-Step Instructions
Step 1: Remove Old Drip Edge (If Replacing)
If you are adding drip edge to an existing roof or replacing deteriorated drip edge, carefully pry the old material away from the deck and fascia. Use a flat pry bar to lift any roofing nails. If the old drip edge is rusted through, cut it with tin snips where needed and remove it in sections. Inspect the fascia board behind the old drip edge for rot -- repair any damaged fascia before installing new drip edge.
Step 2: Measure and Cut
Measure the total linear footage of eaves and rakes separately. Cut drip edge sections to length with tin snips. For corners, you will make special cuts (see Step 6). Cut with the finish side up to prevent burring the visible edge.
Step 3: Install Eave Drip Edge
Begin at the corner of the eave farthest from the prevailing wind direction (so overlaps face away from wind-driven rain).
- Place the first section of drip edge along the eave with the deck leg flat on the deck surface and the fascia leg hanging over the edge.
- The bottom edge of the fascia leg should extend into the gutter (if present) by about 1/2 inch, directing water into the gutter channel rather than behind it.
- Nail the deck leg every 12 inches using roofing nails driven into the deck. Place nails about 1-1/2 inches from the roof edge so they are covered by the starter strip and first course of shingles.
- Overlap the next section 2 inches over the first, maintaining the same alignment. Apply a dab of roofing sealant between the overlapping pieces.
- Continue along the full length of the eave.
Step 4: Install Underlayment
After the eave drip edge is nailed down, install your underlayment (felt or synthetic) over the eave drip edge. The underlayment should overlap the drip edge by at least 1/2 inch so that water running down the underlayment flows onto the drip edge and into the gutter. Follow manufacturer instructions for underlayment overlap and fastening.
Step 5: Install Rake Drip Edge
Now install drip edge along the rakes (sloped side edges). The rake drip edge goes on top of the underlayment.
- Start at the bottom of the rake (at the eave corner) and work upward toward the ridge.
- The deck leg lies flat on the deck over the underlayment, and the fascia leg hangs over the rake edge.
- Nail every 12 inches into the deck.
- Overlap upper sections 2 inches over lower sections (upper pieces on top, so water flows over the joint, not under it).
- At the ridge, trim the drip edge flush with the ridge line.
Step 6: Cut Corners
Where the eave drip edge meets the rake drip edge at the lower corners, you need a clean transition.
- Extend the eave drip edge to the very end of the eave.
- Cut the bottom of the rake drip edge's fascia leg at a 45-degree angle so it mates cleanly with the eave drip edge.
- Overlap the rake drip edge on top of the eave drip edge at the corner so water flows from the rake piece down onto the eave piece.
- Apply a generous bead of roofing sealant to the corner joint.
Step 7: Seal and Inspect
After all drip edge is installed:
- Verify all joints overlap correctly (upper pieces on top of lower pieces)
- Apply sealant to any joints that are not tight
- Confirm the fascia leg extends into the gutter channel
- Check that nail spacing is consistent at 12-inch intervals
- Ensure the underlayment-to-drip-edge relationship is correct (under at eaves, over at rakes)
Common Mistakes
- Installing drip edge OVER underlayment at the eaves -- This is the most common error. Water migrates under the underlayment and behind the drip edge, defeating its purpose.
- Leaving gaps between sections -- Even a small gap allows water to reach the fascia. Always overlap at least 2 inches.
- Nailing the fascia leg instead of the deck leg -- Nails should only go through the deck leg, into the deck sheathing. Nailing the fascia leg splits it or causes it to buckle.
- Not extending into the gutter -- The drip edge should direct water into the gutter, not onto the fascia behind the gutter.
- Skipping drip edge at the rakes -- Wind-driven rain is more likely to penetrate at the rakes than at the eaves. Rake drip edge is just as important.
