A look at types of drip edge flashing, how to cut it, and how to retrofit it to an existing roof
Drip edge flashing is any flashing that protects a building element by shedding water. The leading edge of the flashing is called the 'drip edge'.
In this video, @PaulRicalde shows the two main types of roof drip edge flashing, how to cut both inside and outside corners on them, and how to retrofit drip edge on a simple roof.
Turns out not all drip edge flashing perform the same. Some drip edge flashings actually help houses turn to mush.
Drip Edge Roof Flashing Types:
- L-shape drip edge is a simple 90-degree bend with a flare out at the bottom of the short leg.
- T-shape drip edge is an L-shaped flashing in which the long leg folds back on itself before heading down 90-degrees to form the short leg. It is also sometimes called D-metal (for Drip).
A T-shaped drip edge flashing is better because it adds distance between the edge of the roof and the fascia.
Paul shows a few types of snips and explains a little about why they are called what they are called. Aviation snips come in right and left-hand versions. Right-handed snips can cut circles to the right. Left snips can cut circles to the left. You can also just use tinning snips, which cut straight.
At 7:05 Paul begins replacing the drip edge roof flashing
Use a flat pry bar to remove drip edge nails along the eave and rakes. You may need to use a putty knife to break the seam between the first course and the starter strip.
Slide the flat bar under starter course, and pry out the nails.
On some roofs, you may need to remove a couple of shingle nails to make some room to work.
Because Paul is working alone, he sets the drip edge flashing in place on the rake and cuts and bends it in place.
Three tips for overlapping drip edge flashing:
- Overlap pieces at least a couple of inches shingle-style, with pieces higher up on the roof overlapping pieces lower down. This keeps the water on top of the flashing and away from the roof deck.
- When lapping the eave metal, overlap them so the seam faces away from the direction of prevailing view. If the typical view is from right to left, place the left piece under the right piece.
- Tip 2 is vetoed by prevailing winds for places with wind-blown rain issues.
To cut the lower rake piece in place, slide the lower piece downhill enough to make room to mark, cut, and bend. Mark the straight cuts with a speed square. Cut the initial square cut across the single-ply piece of the top. Next cut back square across the folded part of the top of the T. Cut the 45 degree bird's mouth to allow the long end to be folded around the rake to the eave.
TIP: Make sure to support the long end of the cut — if you let it fall after cutting, it will bend down and kink the drip edge.
Be sure to tuck the drip edge under the starter strip and felt paper. Slide the corner tight to the fascia. Make sure the corner is tight, and that the bottom edge is tight to the fascia before nailing off the drip edge. Place a nail at one end, then the other.
You may need to nail through the starter strip into the drip edge. If you do, make sure the nails will not align with any shingle seams or cutouts above.
Another tip: When sliding metal, if it doesn't slide in easily, don't force it. Go over and look to see why it is stuck.
[One more tip: Wear gloves. Metal edges are sharp and can cut surprisingly deep (trust us).]
—Paul Ricalde is a home improvement contractor and fireman in New Orleans, LA. His YouTube channel is rich with construction/remodeling videos. This article was lightly edited for clarity 12/18/19.