What Holds Your Roof On

The Roofing Series, Lesson 3 · Taught by Professor Elias Walls · Researched and reviewed by Grant Doutt, Certified Master Inspector®

🎓 The Professor's Quick Answer

Florida law requires insurers to give you a discount for construction features that help your home survive a hurricane. The way you prove you have them is the wind mitigation inspection, recorded on a state form every insurer in Florida must accept.

That form changed this year. On April 1, 2026, the state replaced the version used since 2012 with a rewritten one built on a 2024 study of how homes actually performed in real hurricanes. It went from seven rated features to nine, and it now demands a photograph or document proving every single feature claimed.

Two rules decide what you get: the form grades the weakest example of each feature on your house, and opening protection is all or nothing. One unstrapped truss or one unprotected window can erase a credit across the whole home.

🏫 Welcome Back to the Knowledge Center

Last class we read the roof from the outside in. Today we look at what's holding it down, and at the one inspection that can put money back in your pocket every year for the next five.

A wind mitigation inspection isn't about finding defects. Nothing on this form is a repair list. It's a set of questions about how your house was built, and each answer moves a number on your insurance bill.

🌀 How We Got Here: August 24, 1992

None of this existed before Hurricane Andrew.

Andrew came ashore in South Florida on August 24, 1992 with winds around 165 mph. It destroyed more than 63,000 homes and damaged well over 100,000 more, and the damage ran past $25 billion in 1992 dollars.

Then the investigators went in, and what they found was worse than the storm. Entire neighborhoods in Homestead had come apart not because of where they sat, but because of how they were built. Roof sheathing had been stapled down and blew off in sheets. Trusses were toe-nailed to the walls with nothing holding them down. Windows and doors failed the moment debris hit them, and once the wind was inside the house, it pushed the roof off from below.

The root problem was that Florida had no single building standard. More than 400 separate local codes covered the state, unevenly written and, in many places, barely enforced. One analysis attributed roughly $4 billion of insured loss in Miami-Dade to poor code enforcement alone.

What followed shaped every home built here since:

• 1994: Miami-Dade adopted a rewritten South Florida Building Code, the first serious post-Andrew standard, which created the testing regime that produced the impact window industry.

• 1998 to 2002: the Legislature created the Florida Building Commission, and on March 1, 2002, a single statewide Florida Building Code replaced the patchwork, with tougher rules for the High-Velocity Hurricane Zone in Miami-Dade and Broward.

• Along the way, the state required insurers to discount premiums for the features that proved themselves in Andrew's aftermath, which is where your wind mitigation inspection comes from.

Every question on that form traces back to something that failed in 1992. The straps, the nailing patterns, the impact-rated openings, the sealed deck: those aren't arbitrary. They're the list of what the storm tore apart first.

💵 Why the Discount Exists

Florida Statute 627.0629 requires insurers to give discounts, credits, or rate differentials for construction features that reduce hurricane losses. The insurer doesn't get to decide whether to offer them. What it can ask for is proof, and the proof is this form.

Two things worth knowing up front:

• The credits apply to the windstorm part of your premium, not the whole bill. In Florida that's still a large slice.

• The form is good for up to five years, as long as no material changes are made to the structure and nothing on it turns out to be inaccurate.

🆕 What Changed on April 1, 2026

For fourteen years, every wind mitigation inspection in Florida used the same form. That version is retired. Inspections done on or after April 1, 2026 must use the new one. Citizens has said it will still accept a 2012-version form completed within the five years before that date, as long as nothing about the structure has changed.

The differences that matter to you:

• Two new questions. The form now records your Region, based on design wind speed where the house sits, and your roof slope, graded at 6:12 and steeper versus shallower than 6:12.

• Proof for everything. At least one photograph or document must accompany the form for every attribute marked in questions 2 through 9. An inspector's word is no longer enough.

• FORTIFIED certificates count. A FORTIFIED Home Roof, Silver, or Gold certificate can validate several of the questions.

• A new answer for damaged openings. More on that below, because it's the one that can cost you everything.

• New paths for modern materials, including spray foam applied to the underside of the deck, both as a deck attachment method and as a sealed roof deck.

📋 The Nine Questions, in Plain English

1. Building Code. Which edition of the Florida Building Code was in force when the home was permitted. Homes permitted under the 2007 code or later sit in the strongest category. This is why a 2002/2003 or 2007/2008 home may need its permit application date pulled to land in the better bucket.

2. Region. New this year. Where your home sits by design wind speed: the High-Velocity Hurricane Zone, or Region 1 at 140 mph and above, Region 2 at 130 to 139, or Region 3 under 130.

3. Roof Slope. Also new. Whether the main roof is 6:12 or steeper, or shallower than that.

4. Roof Covering. Every covering type on the home, with its permit date or product approval number and the year it was installed. This is where Lesson 1's roof clock meets this form. A roof with no permit and no product approval documentation is marked as having no information provided, and that hurts.

5. Roof Deck Attachment. How the plywood or OSB is fastened to the trusses, graded by what's weakest anywhere on the roof:

• Staples or 6d nails at 6 inches on the edge and 12 in the field, the low end

• 8d common nails at a maximum of 12 inches in the field, better

• 8d common nails at a maximum of 6 inches in the field, best of the nailing options

• Reinforced concrete deck, and now spray foam rated at 110 psf uplift

If there's no attic access, the inspector has to mark that, and nobody can claim a credit for something no one could see.

6. Roof to Wall Attachment. The connection between the trusses and the walls, and typically the most valuable answer on the form. From weakest to strongest:

• Toe nails: nails driven at an angle through the truss into the top plate

• Clips: metal connectors that don't wrap over the truss

• Single wraps: a strap that wraps over the top of the truss, nailed on both sides

• Double wraps: two straps, one on each side, or a single strap secured with at least three nails on each side

• Structural: anchor bolts or a reinforced concrete roof

Again, the weakest connection on the house sets the answer. The new form also added an answer for connectors that are present but not installed as intended, which is exactly what we find when straps are nailed in the wrong holes or are missing nails.

7. Roof Geometry. Hip or not. A hip roof slopes on all sides with no flat vertical gable ends, and it handles wind far better. To qualify, non-hip features can't exceed 10% of the total roof perimeter, and the inspector has to measure and write down both numbers. A small gable over the entry can cost you the credit.

8. Sealed Roof Deck (SWR). Whether there's a second line of defense bonded to the deck if the covering blows off. This is where Lesson 2's peel-and-stick comes back. The new form accepts a fully adhered ASTM D1970 membrane, taped deck seams, a double layer of felt or synthetic, or spray foam. Standard underlayment and hot-mopped felt still don't qualify.

9. Opening Protection. Every window, door, sliding glass door, skylight, and garage door, graded by the weakest one. Levels run from verified impact-rated products at the top, down through code-compliant plywood, unverified shutter systems, no protection at all, and now damaged openings in need of repair or replacement.

Read that last one twice. The form says that buildings with openings that need replacement do not qualify for wind mitigation rate differentials at all, regardless of the presence or absence of other features. A single broken window can wipe out every credit on the form.

⚠️ The Two Rules That Cost People Money

The weakest one wins. Deck attachment, roof-to-wall, and opening protection are all graded by the worst example we find. Twenty-three trusses with double wraps and one on toe nails makes it a toe-nail house. There's one exception written into the form: hip and valley jacks within five feet of a roof corner don't count when determining the weakest roof-to-wall connection.

Opening protection is all or nothing. One unprotected bathroom window, one skylight, or one non-rated garage door drops the whole house to the level of that opening. Garage doors are the most common offender, because they're big, and they often aren't rated.

🪚 "It's One Broken Board." Why a Damaged Truss Is a Big Deal

We find broken, cut, or modified trusses more often than you'd think, and the reaction is almost always the same: there's a whole attic full of lumber up there, so what's one piece?

Here's why it matters.

A truss is not a stack of boards. It's an engineered machine. Every member in it was sized by an engineer for a specific job. The top chords carry the roof down, the bottom chord ties the walls together and resists them being pushed apart, and the webs in between move load between the two. Some members are in compression and some in tension, and the whole thing only works as a closed triangle. Remove one web and the triangle can open.

Load goes somewhere. When a member is cut or broken, the load it was carrying doesn't disappear; it shifts to neighboring members and to the next truss over, which were designed to carry their own share and nothing more. Under everyday loads you may see nothing at all. Under a storm you find out.

Your roof is a chain, and this is a link in it. Wind lifts the covering, the covering pulls on the deck, the deck pulls on the trusses, the trusses pull on the walls, the walls pull on the foundation. Every wind mitigation question we just walked through is about one link in that chain. A broken truss is a damaged link in the middle, and no amount of strapping at the wall fixes a truss that's failing above it.

Failures start at one point. Roofs don't come off all at once; they come off where they're weakest. The whole logic of the wind mit form, where the weakest example sets your grade, exists because that's how buildings actually fail. One damaged truss in a hurricane is exactly the kind of starting point the form is designed around.

How they get damaged. Most of what we find wasn't caused by weather:

• Air conditioning and duct installers cutting a web out of the way for a duct run

• Plumbers and electricians notching a chord to get a line through

• Homeowners cutting members to build a storage platform or widen an attic opening

• Damage during delivery or framing that never got corrected, which is one more reason a pre-drywall inspection matters on a new build

• Truss plates that have backed out, rusted, or were never fully pressed in at the plant

The fix isn't a piece of lumber and some nails. A damaged truss needs a repair designed for that truss by an engineer, usually a detail specifying plates or scabs, sizes, and fastener patterns. "We sistered a 2x4 to it" is not a repair; it's a hope. A homemade fix can also complicate an insurance claim later, because the truss no longer matches the engineering the house was permitted under.

So when a report flags a cut or broken truss, treat it as a structural item with a documented repair, not a scratch on the paint. It's one board holding up a share of everything above your family's head.

📸 Bring the Paperwork

The new form's documentation rule is where inspections now succeed or fail. Every marked attribute in questions 2 through 9 needs a photo or document. What helps most:

• The roof permit and the product approval number for your covering

• Permit application dates if your home was built in 2002, 2003, 2007, or 2008

• Product approval or NOA documents for impact windows, doors, and shutters. Without them, protection that looks impact-rated gets marked as unverified, which pays less

• Any FORTIFIED Home certificate, which the new form accepts to validate several questions

Dig those out before the inspection. Documents found afterward often mean paying for a re-inspection.

✍️ Who Can Sign It

State law limits who may certify this form. Licensed Florida home inspectors qualify, but only after completing state-approved hurricane mitigation training and passing a proficiency exam. Building code inspectors, licensed contractors, engineers, and architects also qualify.

Home inspectors must perform the inspection personally, not send an employee. And the fraud language on the form isn't decoration: knowingly submitting a false or fraudulent mitigation form is a crime, and the inspector who signs it is directly liable.

That protects you. A credit obtained on a form that can't be supported doesn't survive the first claim.

🔧 What You Can Actually Change

Some answers are fixed the day the house is built. Others aren't:

• At re-roof time, ask about deck re-nailing. Bringing the sheathing up to the 8d-at-6-inches standard is cheapest when the covering is already off.

• Ask for a sealed roof deck at re-roof. Same logic: it's a modest add-on during a job you're already paying for, and it's an answer on the form.

• Opening protection can be retrofitted, but only in full. Half the windows gets you nothing, so plan to do every opening, garage door included.

• Fix damaged openings before the inspection, since under the new form they can disqualify everything.

• Straps can sometimes be retrofitted, though it's more involved. Worth pricing if your home is on toe nails.

❓ Questions From the Back Row

"I had a wind mit done in 2023. Do I need a new one?"

Not necessarily. A 2012-version form completed within five years before April 1, 2026 is still accepted, provided nothing structural changed. But if you've re-roofed, added shutters, or replaced windows since, a new inspection on the new form is how you get credit for it.

"My house is from the 1980s. Is it even worth it?"

Usually yes. Older homes often have hip roofs, and if a previous owner re-roofed, you may have deck nailing and a sealed deck you don't know about. The only way to find out is to look.

"We put impact windows in but our premium didn't move."

Two likely reasons: a garage door or entry door that isn't rated, so the all-or-nothing rule caps you, or no product documentation, so the windows were marked unverified. Find the paperwork from the installer.

"Does a new roof automatically improve my wind mit?"

Not automatically. It improves the roof covering answer, and it's your chance to improve deck attachment and add a sealed deck, but only if those are specified in the contract. Ask before the work starts, not after.

"Who keeps the form?"

You do. Keep a copy with your policy documents, and hand it to your agent at every renewal and to any new carrier you shop. A form sitting in a drawer earns nothing.

🚌 Field Trip — Class Dismissed

Find out whether you have a current wind mitigation form. Check your policy documents, then ask your agent whether one is on file and which mitigation credits are actually being applied to your premium. That last question surprises people. Credits sometimes never get entered, and nobody notices.

While you're at it, walk the outside and count your openings: every window, exterior door, skylight, and garage door. Which ones are protected, and which aren't? That count is your opening protection answer in a nutshell.

Next class: where roofs really leak. Flashing, valleys, pipe boots, and what the attic reveals that the roof surface hides.

Sources: Uniform Mitigation Verification Inspection Form OIR-B1-1802 (Rev. 04/26), adopted by Rule 69O-170.0155, F.A.C., effective April 1, 2026, Florida Office of Insurance Regulation; Florida Statutes § 627.0629 and § 627.711; Citizens Property Insurance Corporation bulletin on the revised form; published histories of Hurricane Andrew and the development of the Florida Building Code. Credits and underwriting rules vary by insurer; confirm with your agent.

Buying a home in Clermont, Lake County, or anywhere in Central Florida? Call (352) 272-1322 or visit fourcornershomeinspections.com.

Taught by Professor Elias Walls · Researched and reviewed by Grant Doutt, Certified Master Inspector® · Last reviewed: September 2026. Professor Elias Walls is the teaching persona of the Four Corners Knowledge Center. Every lesson is researched, written, and fact-checked by the licensed, certified inspectors of Four Corners Inspection Services.