What Is Drip Edge and
Why Do Inspectors Flag It So Often?

What Is Drip Edge?

Drip edge is an L-shaped or T-shaped metal flashing, typically aluminum or galvanized steel, installed along the lower edge of a roof at the eave and along the sloped ends of the roof at the gable rakes. It sits between the roof decking and the shingles, with the outer lip hanging over the fascia board.

Its job is to direct water off the roof edge and into the gutter cleanly, rather than allowing it to run back under the shingles or down the face of the fascia. The name describes the function exactly: it creates a defined drip point so water leaves the roof edge in a controlled way.

What Happens Without It?

Without drip edge, water at the roof edge behaves unpredictably. In a light vertical rain it may run off cleanly. In wind-driven conditions, heavy rain, or where there is any capillary pull at the shingle edge, water can travel back under the bottom shingle course and contact the roof deck directly.

Over time this produces three common consequences:

• Fascia deterioration. Water running down the face of the fascia rather than dripping from a defined metal edge keeps the wood consistently damp. In Portland’s climate, sustained moisture contact degrades paint and eventually causes rot in the fascia board.
• Roof deck edge damage. The OSB or plywood at the very bottom of the roof is vulnerable to moisture once the shingle layer is bypassed at the edge. Edge rot on the roof deck is a common finding on older roofs that were never installed with drip edge.
• Water bypassing the gutter. Without a defined metal edge, water can miss the gutter entirely during wind-driven rain, particularly at the rake ends where it runs off the slope without being directed into a downspout.

Two Locations, Two Roles

Eave Drip Edge

Installed along the horizontal lower edge of the roof before the underlayment. Directs water off the shingle edge into the gutter. The most critical location because water volume is highest here.

Rake Drip Edge

Installed along the sloped ends at the gable edges over the underlayment. Protects where shingles are most vulnerable to wind uplift and where water runs off without a gutter below.

Is Missing Drip Edge a Code Issue?

In Oregon and Washington, current code requires drip edge on new asphalt shingle roofs. However, many older Portland homes were built before this was required. A home from the 1950s or 1960s without drip edge was not necessarily installed incorrectly at the time. It reflects a standard that evolved.

Missing drip edge typically only becomes a code requirement again when the roof is being replaced, since a new asphalt shingle roof is expected to meet current code, drip edge included. This makes a planned roof replacement a natural opportunity to address it if it has not been done before.

What Does Installation Cost?

Drip edge material costs roughly $1 to $2 per linear foot. On a standard Portland home, the material cost is modest. Labor depends on whether the existing shingles need to be carefully lifted along the edge to install it correctly, which adds time but is feasible on a roof in serviceable condition.

If drip edge is missing and a roof replacement is already being discussed, it is simply included in the roofing contract. If the roof is in serviceable condition and drip edge is the primary issue, addressing it now can help limit further fascia and deck edge deterioration. See our pricing page for inspection costs in Portland and Oregon City.

Questions about roofing findings on your report? Visit our FAQ or call (971) 202-1311.