- Its job: water into the gutter, not behind it
- Code: required on new asphalt roofs
- PNW: stops fascia rot in 40″+ rain
- Local crews — SW WA & Portland metro
A drip edge is a strip of metal flashing installed along a roof’s eaves and rakes that directs water off the edge and into the gutter instead of letting it wick back behind it. In the rainy Pacific Northwest it’s what stands between your roof and rotted fascia, pest entry, and sagging shingle edges — and current building code requires it on new asphalt-shingle roofs. Many older homes here don’t have one; adding it during a re-roof brings the roof up to code and protects the shingle warranty.
Drip edge is one of those small, cheap parts that does a wildly outsized job — and one of the first things we check on an older Clark County or Portland-area roof. It’s easy to overlook because it’s mostly hidden, but in a climate that throws 40-plus inches of wind-driven rain at a roof every year, whether or not you have a proper drip edge is the difference between fascia that lasts and fascia that rots out in a couple of seasons. One note up front: we’re roofers, not code officials — confirm any code or permit specifics with Clark County or your city.
What a drip edge actually does
A drip edge is bent metal flashing — an L or T profile — installed along the edges of the roof, under the shingles at the eaves and over the underlayment at the rakes. Its job is simple but critical: it breaks the surface tension that makes water want to cling to and run back under the roof edge, and instead kicks that water cleanly out and down into the gutter. Without it, rain running off the roof follows the underside of the shingles back toward the fascia and sheathing. Over one Northwest winter that’s a nuisance; over several it’s rot.
A properly installed drip edge also stiffens the roof edge, closes the gap where wind-driven rain and pests (wasps, rodents, birds) try to get under the first course of shingles, and keeps the shingle edges from sagging and curling over the gutter line.
Why PNW roofs especially need one
In a dry climate a missing drip edge is a slow problem. Here it’s a fast one. Our rain is heavy, persistent, and often wind-driven — which is exactly the condition a drip edge is built to handle. Without one:
- Fascia and sheathing rot. Water wicking behind the gutter soaks the fascia board and roof deck edge. In our climate that wood rarely gets a chance to dry, so rot sets in fast — sometimes within a couple of years.
- Gutters pull away. Rotted fascia can’t hold gutter spikes and hangers, so the gutters themselves start to sag and fail.
- Shingle edges sag and curl over the roof edge without the metal to support them, letting even more water track backward.
- Pests get in through the open gap at the roof’s edge.
It’s the same wind-driven-rain problem behind a lot of PNW roof failures, concentrated at the most vulnerable inch of the whole roof — the very edge.
Drip edge and building code
Drip edge isn’t optional on a new asphalt-shingle roof — it’s required by code. The relevant provision is IRC R905.2.8.5, which calls for a drip edge at eaves and rakes, with specified overlap between sections and a set extension below the roof sheathing.
Here’s where it matters for older homes: many roofs built before the requirement was enforced simply don’t have a drip edge, and adding one during a re-roof is a legitimate code upgrade. That’s worth knowing on an insurance job — when a covered claim triggers a roof replacement, “Ordinance & Law” coverage on many policies can pay to bring the roof up to current code, drip edge included. It’s the classic example of a code-required item an older roof is missing.
Does your roof already have one?
You can often tell from the ground. Look along the eaves and gable edges for a thin metal lip running just above the gutter and along the rake edges — usually painted to match the trim or a plain mill finish. If the shingles end in a bare edge that overhangs into space with no metal beneath them, or if you can see the wood fascia right up to the shingle line, there’s likely no drip edge. When in doubt, it’s one of the first things we confirm on an inspection — along with the condition of the fascia behind it.
Adding a drip edge to an older roof
The honest answer on retrofitting: a drip edge is installed with the roofing, tucked under the shingles at the eaves, so the clean and correct time to add one is during a re-roof. Trying to slide metal under an existing, sealed shingle course after the fact is a compromise at best and can do more harm than good. If your roof is otherwise near the end of its life and missing a drip edge, that’s one more reason a full replacement — done right, to code — beats another patch. It’s also the moment to fix any fascia that’s already been damaged and make sure your gutters are draining properly.
Aluminum vs. galvanized drip edge
Two materials come up most often. Both work; the trade-off is corrosion resistance versus stiffness and cost.
| Aluminum | Galvanized steel | |
|---|---|---|
| Corrosion | Won’t rust — well suited to our wet climate | Can rust over time if the zinc coating is scratched or wears |
| Cost | Slightly higher | Economical |
| Strength | Softer, dents more easily | Stiffer and stronger |
| Finish | Many colors, holds paint well | Mill or painted |
| Best for | Most PNW homes, where rust resistance matters most | Budget jobs or lower-exposure edges |
For the wet Pacific Northwest we generally lean aluminum for its rust resistance, but the right call depends on the roof and budget — we’ll walk you through it.
Worried about your roof’s edges or fascia?
We’ll check whether your roof has a proper drip edge, look at the fascia behind it, and tell you straight what — if anything — needs doing. No pressure. Serving Portland, Vancouver & all of SW Washington.
Book a free roof inspection WA (360) 952-3998 · OR (503) 523-3449Frequently asked questions
What does a drip edge do?
A drip edge is metal flashing along the roof’s eaves and rakes that directs runoff off the edge and into the gutter instead of letting it wick back behind the edge. It breaks the surface tension that would otherwise pull water under the shingles toward the fascia and sheathing, so it prevents rot at the roof’s edge. It also stiffens the edge, closes the gap where wind-driven rain and pests get in, and keeps shingle edges from sagging over the gutter. It’s a small, inexpensive part that protects the most vulnerable inch of the whole roof.
Is a drip edge required by code?
Yes — on new asphalt-shingle roofs, a drip edge is required at the eaves and rakes under the International Residential Code (the provision is commonly cited as IRC R905.2.8.5), with rules for how sections overlap and how far the metal extends below the sheathing. Local jurisdictions in Washington and Oregon adopt and sometimes amend the IRC, so confirm the exact requirement with your city or county. The practical point for homeowners: on any new roof or full re-roof, a drip edge should be part of the job. Older roofs installed before the requirement often lack one.
What’s the difference between a drip edge and a gutter apron?
They’re closely related edge flashings that solve the same problem in slightly different spots. A drip edge is the general term for the metal along both the eaves and the rakes. A gutter apron is a specific eave flashing with a longer, angled leg that extends down into the gutter, giving water an even more direct path in — it’s especially useful where water tends to overshoot or wick behind the gutter. Many quality installs use a true drip edge at the rakes and a gutter apron at the eaves. Both do the same core job: keep water off your fascia and in the gutter.
What happens if a roof doesn’t have a drip edge?
Water running off the roof follows the underside of the shingles back toward the fascia and roof deck instead of dropping into the gutter. In the wet Pacific Northwest, where that wood rarely gets to dry out, the result is fascia and sheathing rot — sometimes within a couple of years. As the fascia rots it stops holding the gutters, so those start to sag and fail too, and the exposed roof edge becomes an entry point for pests. It’s a small missing part that leads to some of the more expensive edge and gutter repairs we see.
Can a drip edge be added to an existing roof?
The correct time to install a drip edge is during roofing, because it tucks under the shingles at the eaves and over the underlayment at the rakes. Trying to force metal under an existing, sealed shingle course afterward is a compromise and can sometimes do more harm than good. So on a sound, newer roof it’s usually not worth retrofitting. But if your roof is missing a drip edge and is already near the end of its life, that’s a solid reason to add one as part of a full re-roof — done properly, to code — rather than patching around the problem.
Does a drip edge cost extra?
Not with us. At Jobin, drip edge is part of the standard scope on every re-roof — it’s included as a matter of course, not quoted as a separate line item or an add-on. So the honest answer to “what does it cost” is that on a proper roofing job it’s simply built in. If you’re comparing bids, it’s worth confirming drip edge is actually included in each one — on some low bids it isn’t, and that’s exactly the kind of code-required detail a corner-cutting quote leaves out.
