Is Drip Edge Required on a Roof in Florida? Code and Install Rules

What is drip edge on a roof?

Drip edge is a bent strip of metal installed along the edges of a roof. It sits where the shingles and underlayment end, at the eaves (the low edge) and the rakes (the sloped edges at the gable ends).

A gable is the triangle of wall at the end of a peaked roof. The rake is the roof edge that runs up along it. Florida's code uses the word "gables" for those edges, and roofers say "rakes." They mean the same edge.

The code does not explain why it requires drip edge, but the maker and research guides do hint at the job. The Pacific Northwest National Laboratory says shingles should overhang the drip edge a little so water drains off, and that in wildfire areas metal drip edge protects wood fascia from embers. IBHS says its FORTIFIED roof program adds extra drip edge details to protect the roof edge.

Roofers install it, and most homeowners never see it up close, because it is a thin line at the edge. It goes on during a replacement, after the old covering is off and the deck is clean, and before the shingles. Atlas lists drip edge, flashings and an approved underlayment as part of preparing the deck. The underlayment at the eaves overhangs the deck edge by 1/4 to 3/8 inch in Atlas's instructions.

This page is about shingle roofs. The code section we cover is in the asphalt shingle part of the code. Tile and metal roofs have their own edge details in other sections, which we did not review here.

Does drip edge go over or under the underlayment?

The two documents we read give different answers for the eaves. The code text says over the underlayment. Atlas's instructions say under it at the eaves and over it at the rakes.

The Florida code text we read says to install drip edge over the underlayment, with a 4-inch band of roof cement over the flange. Atlas Roofing's Pinnacle Pristine instructions say to place corrosion-resistant drip edge over the underlayment at the rake and beneath the underlayment at the eaves. Atlas also says the roof must meet local code or the shingle maker's requirements, whichever is stricter.

Under FORTIFIED, IBHS's voluntary roof program, the Pacific Northwest National Laboratory's guide says drip edge goes over the underlayment and the starter strip is set in a flashing cement band at least 8 inches wide, no thicker than 1/8 inch. Starter strips and shingles may not extend more than 1/4 inch past the drip edge. Outside FORTIFIED, the Pacific Northwest National Laboratory suggests a starter overhang of 1/4 to 3/4 inch for drainage. Atlas's starter course goes on with a 1/4 to 3/4 inch overhang at the eaves.

The practical point for a homeowner is simple. Ask your roofer which order they use, which document it follows, and who checks it. Ask also who checks it. Our guide to roof permits in Florida explains the permit step. If you also want to know about the layer under the edge, read synthetic underlayment vs felt.