Roof Drip Edge Installation: Florida Code, Cost & Mistakes

Drip edge is the metal flashing along the edges of your roof that carries runoff clear of the fascia instead of letting it curl back underneath the shingles. It is required at eaves and gables on every shingle roof in Florida, and it is an inexpensive component that protects the fascia and deck edge from rot.

Florida's code also specifies it in more detail than the national model code — and, remarkably, Minnesota deleted it from its code entirely. That contrast is the clearest way to understand what drip edge is actually for, so it is worth walking through.

What drip edge does

A roof sheds water to its edge. What happens in the last two inches decides whether that water leaves the building or gets into it. Drip edge does four jobs at once:

• Breaks surface tension. Water running down a shingle wants to follow the underside of the edge back toward the building — capillary action, the same effect that makes a poured jug dribble down its own side. The outward bent flange at the bottom of a drip edge, sometimes called a kickout, forces the water to let go and fall.
• Protects the fascia and deck edge. Without it, that curling water lands directly on the fascia board and the exposed edge of the roof sheathing. Those are wood, and in Florida humidity they do not dry out.
• Directs water into the gutter rather than behind it — a missing or wrongly profiled edge can let a gutter appear to work while the fascia behind it rots.
• Stiffens and finishes the edge, giving every shingle course a straight line to land on and holding the edge down against wind uplift.

Drip edge exists to keep water that runs off the shingle edge from getting back underneath it onto the deck or the fascia.

Florida vs Minnesota: the same code, opposite deletions

Both states build residential roofs from the same model code. Both amended it. They deleted opposite sections — and that tells you exactly what each climate does to a roof edge.

In Minnesota's residential code, section R905.2.8.5 — drip edge — reads simply "Deleted." What Minnesota mandates instead is an ice barrier: two layers of cemented underlayment or a self-adhering polymer-modified bitumen sheet, running from the lowest edge of the roof to a point not less than 24 inches inside the exterior wall line. Minnesota's water problem arrives as ice at the eave, melting and backing up under the shingles, so the code spends its attention on a wide waterproof membrane rather than on the metal edge.

In the Florida Building Code, the ice barrier sections — R905.1.2 and R905.2.7 — read "Reserved." Florida deleted them as irrelevant and put the regulatory weight on the edge metal instead, because in Florida water does not creep under the shingles from below. It gets driven there sideways and upward by wind.

Neither state is being arbitrary. They are solving different problems with the same base document. And it explains why generic national roofing advice about drip edge often does not match what a Florida inspector will actually look for.

Exactly what Florida requires

Florida Building Code, Residential, section R905.2.8.5 is unusually prescriptive. On a shingle roof:

• Drip edge is required at eaves and gables.
• Adjacent segments must overlap a minimum of 3 inches — the national baseline is 2, so Florida adds 50%.
• Eave drip edge must extend 1/2 inch below the sheathing and back onto the roof a minimum of 2 inches.
• Drip edge is installed over the underlayment. Self-adhering ASTM D1970 underlayment may instead be installed over a primed drip edge flange.
• A minimum 4-inch width of roof cement goes over the drip edge flange or the self-adhering underlayment.
• Fastening is a maximum of 12 inches on center — and here is the Florida clause that matters most:

Where the allowable-stress design wind speed (Vasd) is 110 mph or greater, which corresponds to about 142 mph on the ultimate wind speed maps, or the mean roof height exceeds 33 feet, drip edge must be mechanically fastened a maximum of 4 inches on center.

That is three times the fasteners. Whether your home needs the 4-inch schedule depends on the design wind speed at your address and the height of the roof, which your building department can confirm. It is one of the quickest ways to tell whether an edge was installed to Florida code or to habit.

The sequencing question, and where Florida differs

This is the detail installers most often get wrong, because the national guideline and the Florida code point different ways at the eave.

The national model code takes the general approach: underlayment goes over the drip edge along the eaves and under it on the rakes. The logic is water travel: at the eave, underlayment lapping over the top of the metal carries water onto it; at the rake, metal over the top sheds water away from the edge.

Florida's code instead states plainly that drip edge shall be installed over the underlayment, with the option of a self-adhering membrane over a primed flange, and a 4-inch band of roof cement sealing it. The reasoning is wind-driven rain: in a Florida storm, water does not simply run downhill. It is pushed horizontally and upward at the edge, and a sealed metal-over-membrane assembly resists that better than a lapped one.

With a self-adhering membrane over the primed flange, the metal at a Florida eave is effectively sandwiched between two plies of membrane.

The practical rule for a Florida homeowner: the code and the shingle manufacturer's published instructions both govern, and a competent roofer reconciles them rather than picking whichever is easier. If a quote does not say how the edge is being detailed, ask.

The four common profiles

Whatever the profile, the model code says drip edge should extend at least 2 inches back onto the deck and at least 1/4 inch below the sheathing, and an outward bent flange helps throw water clear rather than letting it track back onto wood.

Material choice matters more on the coast

Drip edge is usually aluminium or galvanised steel, occasionally copper. Within 3,000 feet of salt water the choice is not cosmetic.

• Aluminium — does not rust, holds up in salt air, and is the sensible default for coastal Florida. Ours is the standard specification for that reason.
• Galvanised steel — cheaper and stiffer, but the coating is sacrificial. In salt air it eventually gives way, and rust weeping from the roof edge down the fascia is the visible result.
• Copper — excellent and expensive.

This is the same logic that governs every exposed metal component near the coast — salt attacks the small metal parts of a roof long before it touches the covering.

What it costs

Retrofitting drip edge onto an existing roof costs more than installing it during a re-roof, because the shingle courses have to be lifted to get the metal in.

Drip edge is, in other words, the least sensible place on a roof to economise, and the best possible time to address it is during a roof replacement when it is cheapest to do properly.

Signs your drip edge is missing or failing

• Soft, dark or peeling fascia board, especially behind the gutters. This is the classic tell.
• Water marks or staining on the fascia below the roof edge after rain.
• Rust streaks down the fascia — galvanised drip edge reaching the end of its coating.
• A visible gap between the roof edge and the gutter where you can see the deck edge or daylight.
• Gutters pulling away, because the fascia they are fastened to has gone soft.
• Shingle edges curling or lifting along the eave, with no metal underneath to hold the line.
• Nothing at all — on homes built before drip edge was widely required, there may simply be no metal there. Look up at the roof edge from the ground.

Because the damage happens at the fascia and deck edge rather than inside the house, drip edge failure rarely announces itself with a ceiling stain. It shows up as gutter and edge problems first, and by the time the wood is soft the repair has grown from metal to carpentry.

What to ask your roofer

1. "Is new drip edge included, or are you reusing the existing?" Reused edge metal on a new roof is a false economy, so make sure the quote says new.
2. "What fastening schedule?" Ask whether your address is at or above the code's 110 mph Vasd threshold, and if it is, the answer should be 4 inches on center, not 12.
3. "Aluminium or galvanised?" Near salt water, aluminium.
4. "How is it detailed at the eave versus the rake?" A roofer who can answer this specifically is a roofer who has read both the code and the manufacturer's instructions.
5. "Is the fascia sound underneath?" New metal over rotten wood is decoration.

If you are not sure what is up there, our roof inspection is free — the roof edge is one of the specific things we photograph, because FEMA notes the roof border is more at risk from wind uplift and wind-driven rain than the rest of the roof.

Code references are to the Florida Building Code, Residential (2023) and the Minnesota Residential Code (2020). Model code references are to the 2021 International Residential Code. Local amendments and manufacturer instructions both apply — confirm specifics with your permitting authority.