What Is Hurricane Roofing? FORTIFIED Roof and Florida's Rules

What hurricane roofing means

A hurricane attacks a roof in a set order. Wind lifts the edges first. Then it peels back the covering, such as shingles, metal or tile.

Once the covering is gone, rain pours through the gaps in the wood deck underneath. IBHS describes this exact chain: if wind rips off the roof covering, it exposes the wood beneath ¹.

Hurricane roofing is any roof designed to break that chain. It holds the edges down, keeps the covering attached, and adds a second water barrier on the deck so a lost shingle does not become a soaked attic.

The term is informal. The standard most people mean by it is FORTIFIED Roof, a voluntary construction and re-roofing program from IBHS ⁴.

How a hurricane roof works

A hurricane roof works in layers. Each layer covers for the one above it if that layer fails. The diagram below stacks them from the outside in, so you can see what is left protecting the house once the shingles are gone.

The deck stays put. The roof deck is the plywood or OSB sheathing nailed to the rafters or trusses. FORTIFIED asks for ring-shank nails in a closer pattern.

Ring-shank nails have ridges along the shank that grip the wood. IBHS reports that testing shows this nearly doubles the deck's wind resistance compared with smooth nails ¹.

The deck is sealed. Tape or a membrane covers the seams between deck panels. IBHS says sealing the seams can cut water entry by up to 95 percent when the covering is lost ¹.

The edges are locked down. Wind gets its first grip at the eaves and rakes. A wider drip edge and a fully adhered starter strip at the edge make that grip harder to get ¹.

The covering is rated for wind. Shingles, metal, tile and low-slope systems must meet tests suited to the wind risk where the home sits ¹.

Types: the three FORTIFIED levels

Three ways to seal a roof deck

The FORTIFIED re-roofing checklist (version 2022.1) lets the roofer choose one of these methods ²:

1. Tape every deck seam with roof deck flashing tape about 4 inches wide, then cover the deck with #30 felt or an equal synthetic underlayment, fastened with button cap nails at 6 inches along the laps and 12 inches between them.
2. Lay a two-layer #30 felt system, overlapped so that every spot on the deck has two layers, fastened on the same nail pattern.
3. Cover the whole deck with a self-adhered (peel-and-stick) membrane. The checklist notes that manufacturers stress good attic ventilation with this method.

Getting the tape to stick

A sealed deck only works if the tape is fully bonded. An IBHS technical bulletin says flashing tape must be fully adhered with no wrinkles or voids to be accepted ³.

It names two tape types: an ASTM D1970 self-adhering polymer-modified bitumen tape at least 4 inches wide, or an AAMA 711-13 Level 3 tape at least 3¾ inches wide ³.

OSB can be a problem. The bulletin warns that the surface texture or wax on some OSB panels can weaken the bond, and says to use the tape maker's primer where adhesion is marginal.

It also says not to nail or staple the tape to the deck ³. The evaluator must photograph the taped deck on four sides of the house, with the date and address showing ³.

Sources: [3]

Example: a standard re-roof vs a FORTIFIED re-roof

The same asphalt shingle roof, replaced two ways. The FORTIFIED column follows the 2022.1 re-roofing checklist ²; the standard column is a typical code-minimum tear-off where the local code allows it.

The FORTIFIED steps add labor and material at every stage. That is why the cost section below lists drivers, not a price. Our roof cost calculator gives a starting range for the base roof.

Where hurricane roofing is used

Hurricane roofing matters most on the Atlantic and Gulf coasts, but the same methods help anywhere strong wind is common.

Kentucky, far from the coast, runs a grant program for FORTIFIED Roof upgrades aimed at high wind and hail ⁴.

The FORTIFIED program itself describes its aim as strengthening homes against high winds, hail, hurricanes and even tornadoes ⁴.

Location also changes the details. The checklist asks whether the home is within 3,000 feet of saltwater. If so, it requires hot-dip galvanized or stainless steel fasteners ².

For roof coverings other than asphalt shingles, the checklist asks for products rated for the site's wind speed and design pressures, with a floor of 130 mph ultimate wind speed and Exposure C ².

Benefits of a hurricane roof

• Less water inside after a storm. IBHS links a sealed deck to up to 95 percent less water entry if the covering is lost ¹.
• A deck that resists lifting. Ring-shank nails in an enhanced pattern nearly double wind resistance in IBHS testing ¹.
• Proof you can show. A FORTIFIED certificate is written evidence that the roof was built to the standard, issued by IBHS after an evaluator's review ⁴.
• Possible insurance savings. Kentucky's program says the certificate can be shared with your insurer for a premium discount ⁴. Discounts depend on your state and insurer.
• It moves with the house. Kentucky's program notes that certificates transfer when the home is sold ⁴.

Limitations

• It is not storm-proof. The standard reduces damage; it does not promise a roof will survive every storm.
• Re-roofing is usually the moment. The checklist starts by removing all existing roofing, so it fits a planned replacement better than a repair ².
• The deck must be thick enough. On a re-roof, the checklist needs a deck at least 7/16 inch thick on rafters no more than 24 inches apart, or new decking ².
• Paperwork matters as much as nails. Without the evaluator's photos and compliance forms, there is no certificate ².
• Grants have rules. Kentucky's program, for example, does not pay for work started before the grant is awarded or for a roof with an open insurance claim ⁴.

What drives the cost

We do not publish a price for a FORTIFIED roof. These are the parts of the job that add to a standard re-roof:

• Re-nailing the whole deck with ring-shank nails at a close spacing ².
• Seal materials: seam tape and primer, a second felt layer, or a full peel-and-stick membrane ².
• Replacing thin or damaged decking that does not meet the 7/16 inch minimum ².
• Wind-rated shingles or coverings and six-nail installation ².
• Corrosion-resistant fasteners near saltwater ².
• Evaluator fees, which the homeowner pays in Kentucky's program at prices the evaluator sets ⁴.
• Grants can offset part of the cost. Kentucky pays its grant directly to the contractor after the certificate is issued, and the homeowner pays anything above the grant ⁴.

How to get a FORTIFIED Roof, step by step

1. Find a certified FORTIFIED Evaluator. The checklist says you must work with one if you want a certificate ².
2. If you plan to use a state grant, apply and be accepted before you hire a roofer or start work. Kentucky's program rejects projects that started early ⁴.
3. Hire a roofer who knows the standard. Kentucky asks homeowners to pick from an approved FORTIFIED contractor list ⁴.
4. The roofer tears off the old roof, re-nails and seals the deck, and installs edges and covering to the checklist ².
5. The evaluator photographs each stage, and the roofer signs electronic Roofing Compliance Forms ².
6. The evaluator sends the file to IBHS, which reviews it and issues the certificate ⁴.
7. You send the certificate to your insurer and keep a copy with your home records ⁴.

Keeping the designation: upkeep and renewal

A FORTIFIED designation lasts five years ⁴. To renew it, a FORTIFIED Evaluator does a re-designation inspection.

According to Kentucky's program, that inspection checks that there have been no major changes to the structure and that the roof covering is still within its life expectancy.

If so, that is usually all it takes to renew for another five years ⁴.

So normal roof care protects the designation too. Keep gutters clear, replace lost shingles with a roofer who knows the standard, and do not let anyone cut new holes for vents or solar without flashing them correctly.

Keep the certificate, the evaluator's report and the roofer's invoice together. A reminder letter is sent to the home before renewal is due ⁴.

Risks and mistakes to avoid

• Tape that is wrinkled, stapled or poorly stuck to waxy OSB. IBHS will not accept it ³.
• Roof vents that are not tested for wind-driven rain. The checklist asks for ridge and off-ridge vents tested to TAS 100(A) or with Miami-Dade County approval ².
• Gable end vents with no storm cover ready. The checklist asks for temporary protection that can be put up before a storm ².
• Starting a grant-funded job before approval, which can cost you the grant ⁴.
• Climbing on the roof yourself. Deck nailing, sealing and edge work are jobs for a licensed roofer, not a homeowner.

Building codes and product approval

FORTIFIED is voluntary. Building codes are the legal minimum. Under the 2021 International Residential Code, Section R905.2.6, asphalt shingles need at least four fasteners per strip shingle, or the maker's number if higher ⁷.

Section R905.1.1 sets added underlayment rules in areas where wind design is required ⁷. Each state and city adopts its own code edition, so the rules at your address may differ.

Florida goes further in its high-velocity hurricane zone (HVHZ). In the Florida Building Code, Building, Chapter 15, Sections 1512 through 1525 set the HVHZ roofing rules ⁵.

They say every roofing component, system and assembly must have a valid and current Product Approval, and that the approval wins if the maker's literature says something different ⁵.

The HVHZ text we read also calls for 12-gauge annular ring-shank nails with at least 20 rings per inch and tin caps 1⅝ to 2 inches across for certain fastening ⁵.

It limits repairs to 25 percent of a roof area in any 12 months unless the whole roof is brought up to code ⁵.

We read the version posted on floridabuilding.org; the current edition may renumber or change these sections, so confirm with your building department.

Hurricane roofing vs related terms

Common misconceptions

Myth Hurricane roofing is a type of shingle.

Reality It is a whole system. The deck, nails, seal, edges and covering all have a job.

Myth Any new roof in Florida is a FORTIFIED roof.

Reality No. FORTIFIED is a separate, voluntary standard with its own evaluator and certificate ⁴.

Myth A sealed deck is the same as normal underlayment.

Reality Normal underlayment does not have to seal the deck seams. FORTIFIED asks for tape, two layers of felt or a full membrane ².

Myth The certificate lasts as long as the roof.

Reality It lasts five years and must be renewed with a re-inspection ⁴.

Your state and local rules

Hurricane roofing rules depend on where you live. Your city or county building department decides which code edition applies and if your address sits in a special wind zone.

In Florida, ask whether your address is in the high-velocity hurricane zone, because that changes which products you may use ⁵. Some states run grant programs for FORTIFIED roofs and have their own rules on discounts.

Kentucky's program is one example ⁴. Search your state insurance department's site for "FORTIFIED" to see what applies to you. We do not list discounts for states whose program pages we have not read.

When it matters and what to do next

• Your roof is due for replacement anyway: that is the cheapest time to add FORTIFIED steps.
• You live near the coast or in a high-wind area: ask roofers whether they have built FORTIFIED roofs and can name an evaluator.
• Your state has a grant program: apply before you sign a roofing contract.
• You want a discount: ask your insurer in writing what a FORTIFIED certificate would change on your policy.

Keep going

• Storm damage and insuranceHow a roof claim works after a hurricane
• Florida roofing marketOur research on roofing in Florida
• Roof replacementPlanning a full replacement
• Roof sheathingThe deck a sealed roof protects
• Drip edgeThe metal edge FORTIFIED widens

Related terms

Roof Wind Uplift

Roof wind uplift is the upward pull that wind puts on a roof as it flows over and around a building, lifting shingles, panels or the whole deck away from the framing below.

Wind Damage

Roof damage from high wind: lifted, creased or missing shingles, torn-off ridge caps and edges, debris impact.

Roof Sheathing

Roof sheathing is the layer of plywood, OSB or wood boards nailed across the rafters or trusses.

Roofing Nails

Roofing nails are short nails with a wide, flat head that hold shingles to the roof deck.

Drip Edge

Drip edge is a strip of bent metal flashing installed along a roof's eaves and rake edges that carries water off the edge of the roof and away from the fascia and the deck beneath.

Roof Underlayment

Roof underlayment is a sheet laid over the whole roof deck before the shingles or other roof covering go on.

Impact-Resistant Shingles

Impact-resistant shingles are roof shingles that have passed a lab test in which steel balls or ice balls strike the shingle, and earned an impact class from 1 to 4, with Class 4 the highest.

Reroofing

Reroofing is the work of putting a new roof covering on a house that already has one, either by tearing the old covering off down to the deck (a replacement) or by laying the new covering over the old one (a recover, often called an overlay).

Storm Damage

Roof damage from a storm event, including hail, wind and falling trees. It is the usual trigger for a homeowners insurance claim.