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Drip edge installation: how it goes in and what to check

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The order of the layers matters more than the metal. Here is how drip edge goes in and how to judge the result from the ground.

Drip edge installation comes down to one rule: water must run over the metal, never behind it. Get the order of the layers wrong and the edge of the roof becomes a funnel into the fascia. We explain the order so you can judge the work. We do not give the on-roof steps, and we say why below.

The order of the layers

Drip edge is a bent metal strip along the edges of the roof. It carries water off the deck and clear of the fascia board. The sequence is the part people get wrong.

  • At the eaves, the metal goes on the bare deck first. The underlayment then lies over it.
  • On the rakes (the sloped sides), the underlayment goes on first. The metal lies over it.
  • Shingles finish over both, with a small overhang past the edge.

The logic is simple. Water running down the slope hits the eave metal last, so the underlayment must sit on top of it and shed into the gutter. Wind-driven rain at the rake pushes upward, so the metal covers the underlayment there.

Why a missing edge shows up late

A roof without drip edge often looks fine for years. Water then wicks back under the first row of shingles and soaks the deck edge and the fascia. The damage is slow and out of sight. By the time paint peels or a board feels soft, the rot has been there a while. We cover the stains that follow in ceilings and stains.

What good work looks like from the ground

Stand back in the yard with binoculars. Look along each edge.

  • A thin, straight line of metal with a small lip past the shingles.
  • No gaps where two lengths meet. They should overlap by an inch or two.
  • No waves or lifted sections that suggest loose fasteners.
  • Paint or finish that matches the trim, with no rust streaks.

If you have an attic hatch, check under the eaves with a flashlight. Dark staining on the deck near the edge, or damp insulation at the outer wall, points to water getting past the edge. Stay at the hatch and do not walk on the joists.

Why we leave the steps out

Installing drip edge means working at the very edge of the roof, where there is nothing to catch you. It is the most dangerous place on the slope. Most guides skip that fact and list a few steps. We would rather not. Read working at height safely if you want the longer reasoning.

Adding it to an older roof

Many older houses have none. Adding it later is possible, but the order above is harder to reproduce when the shingles are already down. A roofer may lift the first course at the eave or tuck the metal under. Ask which method they plan to use and why. A vague answer is a warning sign.

What to ask a roofer

  • Which pieces go under the underlayment and which go over?
  • Is the metal fastened at a set spacing along the edge?
  • Will the old metal be removed or covered?
  • Can you send photos of the edges before the shingles go on?

A good roofer answers these in plain words. See hiring a roofer for more. We do not publish prices, because they vary too much to help.

Frequently asked questions

What is drip edge?

A bent metal strip along the roof edges that carries water off the deck and into the gutter or clear of the fascia.

Does drip edge go under or over the underlayment?

At the eaves it goes under the underlayment. On the rakes it goes over it. The order keeps water flowing over the metal.

Do all roofs need drip edge?

Most modern building codes call for it, and it protects the deck edge and fascia. Check your local code and ask your roofer.

Can I install drip edge myself?

We recommend against it. It means working at the unprotected edge of a sloped roof. Have a licensed roofer do it.

How do I know if my drip edge is missing?

Look along the edges with binoculars. If the shingles end at the deck with no metal lip, it may be missing.

Sources

What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.

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