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IBHS FORTIFIED Roof: What It Requires and How Homeowners Use It

  • Published November 7, 2026

An IBHS FORTIFIED Roof is a re-roof built to a published checklist: a sealed roof deck, ring-shank deck nails in an enhanced pattern, a wider drip edge, a fully adhered starter strip and wind-rated shingles, with proof of each hidden step needed before the next layer covers it. It makes the most sense when you are replacing the roof anyway, and especially when a grant or a written insurer credit depends on it.

The designation describes how the roof was built, not which product is on it. A Class 4 or “high-wind” shingle does not make a roof FORTIFIED, because the deck, the nails and the edges carry as much of the standard as the shingle does.

What a FORTIFIED Roof Designation Certifies

The Insurance Institute for Business & Home Safety (IBHS), a research nonprofit funded by the insurance industry, runs the FORTIFIED program. Its FORTIFIED Roof overview states that “FORTIFIED requires roof decks to be sealed” so water stays out if shingles are lost, and that it requires “ring-shank nails, installed in an enhanced pattern” in place of common smooth nails, plus “a wider drip edge and a fully adhered starter strip.”

So the designation certifies one thing: that a defined set of installation details went onto this house. It does not certify that the roof will survive a particular storm, that a brand is better than another, or that your premium will change.

FORTIFIED is a prevention decision made before the next storm. If your roof is already damaged, work through the first steps after a storm before planning upgrades; a FORTIFIED re-roof can then become part of the rebuild.

The Requirements on the IBHS Re-Roofing Checklist

Which edition applies depends on your permit date. IBHS’s 2025 technical documents page says that all projects permitted on or after November 1, 2025 “must meet the requirements of the 2025 FORTIFIED Home” standard. Where roof permits are not required, the same rule applies to roofs installed on November 1, 2025 or later. A re-roof planned now is therefore built to the 2025 standard; the older 2020 standard and its checklists apply only to projects permitted, or installed, before that date.

IBHS publishes the 2025 requirements as the Re-Roofing Checklist for FORTIFIED Home designations, version 2024.1, “for use with the 2025 FORTIFIED Home Standard.” These are the items a homeowner can check against the contract and the job photos:

  • Deck thickness. When re-roofing over an existing deck, the checklist requires “7/16 in. minimum deck thickness and a maximum rafter spacing of 24 in. o.c.” A thinner deck has to be re-decked, or a retrofit from a professional engineer may be considered.
  • Tear-off. Remove all existing roofing material and replace any damaged wood.
  • Deck nails. “Nail the roof deck with 8d ring-shank nails at 4 in. o.c.,” and “8d ring-shank nails must be at least 0.113-in. diameter and 2-3/8-in. long,” long enough to reach at least 1-5/8 inches into the rafter or truss.
  • Sealed roof deck. The checklist says to “seal the roof deck (choose one of the following three options)”: 4-inch roof deck flashing tape over all sheathing seams covered by #30 felt or an equivalent synthetic underlayment, a two-layer #30 felt system, or a self-adhered membrane over the entire deck. Each option sets its own underlayment and fastening rules.
  • Drip edge. Installed over the underlayment at rakes and eaves; it “must extend ½ in. below sheathing and extend back on the roof a minimum of 2 in.,” overlap 3 inches at joints, and be fastened at 4 inches on center, staggered.
  • Starter strip. Adhered at the eave and rake, either embedded in roofing cement or self-adhered.
  • Shingle wind rating. Asphalt shingles “must be ASTM D3161 (Class F) or ASTM D7158 (Class H) rated and be installed with six nails per high-wind installation instructions.” The guide to shingle wind ratings explains what Class H and Class F mean and how they differ.
  • Coastal fasteners. Within 3,000 feet of a saltwater shoreline, hot-dip galvanized or stainless steel fasteners are required.
  • Vents. Ridge and off-ridge roof vents must be tested to TAS 100(A).

The checklist contains more line items than this list, and some depend on the roof covering and the house, such as metal, tile or low-slope coverings and roof-mounted equipment. Read the PDF itself with your roofer before signing, and mark each item the contract covers. IBHS’s 2025 summary of changes lists what moved from the 2020 standard.

Why each of these details helps a roof hold in high wind, and how the three deck-sealing methods compare, is covered in the construction details that keep a roof on in a hurricane.

The Hail Supplement: Why a Class 4 Label Is Not Enough

FORTIFIED also has a Hail Supplement. Under it, the IBHS overview says, “asphalt shingles must be rated Good or Excellent on the IBHS Hail Impact-Resistant Shingle Ratings.” That is stricter than a UL 2218 Class 4 label on the bundle: IBHS sorts the products it tests into Excellent, Good, Marginal and Poor instead of a single pass mark, and the supplement accepts only the top two grades.

The ratings move. In its November 19, 2025 ratings release, IBHS reported evaluating 24 impact-resistant shingle products; most earned Good and none earned Excellent. IBHS added that if a product rates Marginal or Poor, “we do not recommend using it in areas that experience hail.”

If you want the Hail Supplement, name the exact shingle product in the contract and check it against the IBHS ratings edition in force when the shingles are ordered. For what a Class 4 rating does and does not prove against real hail, see what a UL 2218 Class 4 rating proves and what it does not.

Getting Verified: What to Arrange Before Tear-Off

The most important FORTIFIED details are the first ones to disappear. Underlayment covers the deck seams and nail heads, and shingles then cover the underlayment. Any proof that the deck was sealed and renailed has to be captured while those layers are still exposed.

For a designation, two parties besides you are required. The 2025 summary of changes says “All components of a FORTIFIED Roof must be installed by a qualified FORTIFIED Wise Roofing Contractor or Company with an active listing in the FORTIFIED Directory.” The checklist adds that a designation certificate, “which is generally required for insurance discounts and/or tax incentives,” requires a certified FORTIFIED evaluator, an independent third-party inspector who verifies the checklist items and submits the documentation to IBHS. After installation, the roofing contractor must complete and sign the Roofing Compliance Forms the evaluator provides.

IBHS sets the evaluator process and the certificate terms, so confirm the current steps with IBHS through its FORTIFIED site before you sign. Treat the roofer’s answers to the questions below as the plan, and get them in writing:

  1. Which standard and checklist will you build to? Ask that the contract name the 2025 FORTIFIED Home Standard and the Re-Roofing Checklist version, unless your permit predates November 1, 2025.
  2. Is your company an active FORTIFIED Wise listing, and who is the evaluator? Check the roofer’s listing yourself in the FORTIFIED Directory, reached through the “Find a Professional” link on the 2025 technical documents page, get the evaluator’s name, and ask at which stages the evaluator needs access or photos and who completes the Roofing Compliance Forms.
  3. Which deck-sealing option will you use? Ask for photos of the sealed deck across each roof plane before underlayment goes on.
  4. How will deck nailing be shown? Photos of the nail pattern with a tape measure in frame, plus the nail packaging showing ring-shank, 8d, 0.113 inch by 2-3/8 inch.
  5. What shingle, with which wind class? Request the product data sheet showing Class H or Class F, and the IBHS hail rating if you are pursuing the Hail Supplement.
  6. What happens if the deck is damaged? Ask how replacement sheathing is priced, because sealing and renailing apply to whatever deck is on the roof.
  7. Who holds the final paperwork? Ask when you will receive the designation document and in what form, since an insurer or a grant program may ask for it.

Keep the photo set yourself. If the designation is delayed or questioned, those photos are the only record of work that can no longer be seen.

Grants That Require a FORTIFIED Roof

A verified designation can also unlock grant money. Some state programs fund roof retrofits only when the finished roof meets the FORTIFIED standard. Alabama’s Strengthen Alabama Homes regulation, Chapter 482-1-159, for example, says the homeowner “must retrofit the home to the Insurance Institute for Business and Home Safety (IBHS) FORTIFIED Roof” standard, and that projects must be completed within three months of the grant approval notice. Amendments to that regulation took effect January 1, 2026.

A completion deadline changes the order of work. If a grant is involved, line up the roofer, the shingle and the verification plan before approval arrives, not after. Eligibility rules, award amounts and how funding rounds work are covered in the roof repair assistance guide, which covers state resilience grants alongside income-based programs.

What to Confirm in Writing Before You Commit

Several facts above carry dates, and each can change between the day you read this and the day your roof is installed:

  • Standard edition. The items above follow the 2025 FORTIFIED Home Standard and its Re-Roofing Checklist, version 2024.1, which apply to projects permitted, or roofs installed, on or after November 1, 2025. A later edition may change them; ask the roofer and the evaluator to confirm which version applies to your job.
  • Hail ratings. The IBHS shingle ratings cited here are the fourth edition of November 19, 2025. A later edition can move a product up or down.
  • Grant rules. Alabama’s regulation was amended effective January 1, 2026, and program terms are set by each state.
  • Insurer recognition. Whether an insurer must give a credit for a FORTIFIED Roof depends on your state and your insurer, so do not assume one.

Send your insurer a short written question before the tear-off date: does the company offer a premium credit for a FORTIFIED Roof designation, which document does it accept as proof, by when must it be submitted, and does the credit continue at renewal? Ask for the answer by email, and after the next renewal, check the premium breakdown on your declarations page to confirm whether any credit was actually applied. If the answer is unclear or contradicts what you were told, your state insurance department is the regulator to ask; NAIC keeps a directory of state insurance departments with contacts and complaint links. How roof credits are calculated and applied is covered in roof-related insurance discounts.

Is a FORTIFIED Roof Worth Pursuing at Your Next Re-Roof?

Pursue it when three conditions line up: the roof is being replaced anyway, you live where hurricane wind or hail is a real threat to the house, and a roofer with an active FORTIFIED Wise listing agrees in writing to build to the checklist and work with a certified evaluator. If a grant requires the designation, it is the condition of the money, so plan verification before approval. If your insurer confirms a credit in writing, add that to the value side.

If the roof still has years of service left and no grant applies, a FORTIFIED re-roof is the wrong tool for now; plan for it at the next replacement. If no grant or credit applies, the checklist details can still be specified on their own merits, but price them as line items and decide on what they do for the roof, not on an assumed discount.

Before you sign, send two written messages: one asking the roofer to follow the IBHS checklist version that applies and to photograph every hidden step, and one asking your insurer what proof it accepts and what, if anything, it changes.

This guide is general information for U.S. homeowners, not legal, insurance, tax, or engineering advice. Codes, laws, and policy terms vary by location and change over time; confirm details with your local building department, your insurer, or a licensed professional.

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