The Texas 25 Percent Rule for Roof Replacement

Here’s the short answer. If a roofer repairs or replaces more than 25 percent of your roof inside any rolling 12-month period, Texas code (IRC R908.1, adopted statewide) says the entire roof has to come up to current standards. That means new underlayment, new drip edge, new ice and water shield where required, and any structural decking that’s rotted or thinner than 7/16” OSB. We’ve had a dozen Plano and Frisco homeowners call us in 2025 confused about why their adjuster denied a partial patch on a 4,200 sq ft roof after the April 9 2024 hail event. The 25 percent rule is usually the reason, and once you understand it, the math gets a lot less scary.

what the 25 percent rule actually says.

The rule lives inside the 2021 International Residential Code, Section R908.1, which Texas adopted with amendments. The text is short. If more than 25 percent of the roof area on a building is replaced or recovered within any 12-month period, the entire existing roof covering has to be removed and replaced in accordance with current code requirements.

That’s the whole rule. But three things get missed:

1. It’s roof area, not roof cost. A 600 sq ft repair on a 2,400 sq ft roof is exactly 25 percent. One more square (100 sq ft) and you’ve crossed.
2. It’s a rolling 12 months, not a calendar year. If your June 17 2024 hail repair touched 18 percent, and a January 2025 wind event touched another 10 percent, you’re at 28 percent and the rule kicks in.
3. It applies whether you replace the shingles or recover them. Texas doesn’t let you put a second layer over an existing roof to dodge the threshold.

A 2,400 sq ft roof crosses the threshold at 600 sq ft of repair, which is roughly one full slope on a standard hip design.

why the rule exists in the first place.

Roofs are systems, not just shingles. When code requires drip edge, ice and water shield in valleys, and synthetic underlayment, those upgrades only work if the whole roof is on the same standard. A 1998 roof patched with 2026 materials still leaks at the seams between old and new.

Texas adopted R908.1 to stop the practice of endless partial patches that left homes with three different generations of underlayment under one shingle field. After Hurricane Harvey in 2017 and the May 28 2023 Allen-Plano hail line, the state got serious about enforcing it.

how this changes an insurance claim.

Here’s where it matters for your wallet. Carriers in DFW (State Farm, Allstate, USAA, Farmers, Liberty Mutual) all know the 25 percent rule. When an adjuster writes a scope that touches more than a quarter of your roof, a properly insured roofer is required by code to do a full tear-off. That triggers what’s called a code upgrade supplement on most policies.

Here’s what that looks like in practice on a real Wylie claim from May 23 2024:

Line item	Adjuster’s first scope	After 25% rule supplement
Shingle replacement (partial)	$4,800	n/a
Full tear-off (28 squares)	n/a	$12,400
Synthetic underlayment	not included	$980
Drip edge (code upgrade)	not included	$640
Ice and water shield (valleys)	not included	$720
Decking (3 sheets rotted)	not included	$345
Total RCV	$4,800	$15,085

The homeowner went from a partial patch they’d have hated in two years to a full new roof. Their deductible stayed the same ($2,500). The carrier paid the rest minus depreciation, which they recovered on completion.

If you want the full breakdown on how supplements work, we walk through it in our hail damage page.

An illustration of code upgrade lines on an insurance scope, including a separate line for roof code compliance.

how we measure the 25 percent on your roof.

We don’t eyeball it. Here’s the process we use on every estimate:

1. Drone or satellite measurement of total roof area in square feet. We use EagleView or our own DJI Mavic for anything under 4,000 sq ft.
2. Damage mapping by slope, marked on the report. Each hit, each slope, each square foot.
3. Math. Damaged area divided by total area. If we’re at 23 percent we tell you. If we’re at 26 percent we tell you. We don’t fudge it either direction.
4. Code citation on the estimate, so your adjuster sees exactly where R908.1 applies.

This is also why we push back when a carrier tries to write a 28 percent scope as a “repair.” The code is the code. It’s not negotiable, and a good supplement gets written within 7 to 14 days.

what triggers the rule on your house.

A few common DFW scenarios that push homeowners over 25 percent:

• One full slope on a hip roof. Most DFW hip designs have a back slope that’s 22 to 30 percent of total roof area on its own. One slope = the rule.
• Two slopes on a gable roof. Gables usually have four to six slopes. Two side slopes will hit the threshold on most 2,000 to 3,500 sq ft homes.
• Hail damage across multiple elevations. This is the big one in DFW. Hail rarely hits just one slope. The May 28 2023 storm came in at a 35 degree angle and hit the south and west slopes of almost every house in Allen, Plano, and Frisco simultaneously.
• A wind event after a prior repair. Rolling 12 months. If you patched in June and the September wind takes off another section, you’re stacking the percentages.

what the rule does NOT cover.

A few things people assume are covered by R908.1 but aren’t:

• Gutters and downspouts. Separate trade, separate code section.
• Flashing on a chimney or skylight that wasn’t damaged. Only the affected roof area counts toward the 25 percent.
• Detached structures. Your garage roof and your house roof are counted separately. A 100 percent garage repair doesn’t drag the main house over the line.
• Solar panel removal and reset. R908.1 is about the roof covering. Solar is its own scope.

If you’ve got a skylight repair bundled into a larger claim, we’ll itemize what counts toward the threshold and what doesn’t so you don’t get blindsided.

A hip roof where the back slope alone made up more than a quarter of the total roof area.

common ways homeowners get this wrong.

We see the same four mistakes:

Mistake one. Letting a roofer do an “unpermitted” partial repair to stay under the threshold. This is illegal in every Texas city we work in. If the work crosses 25 percent, the permit and the code requirements come with it.

Mistake two. Assuming the rule only applies to insurance claims. It applies to any repair or replacement, including cash work. We’ve seen homeowners pay out of pocket for a 30 percent repair only to have the city red-tag the work at inspection.

Mistake three. Filing two separate small claims to stay under 25 percent each time. Carriers track this. Texas Department of Insurance also tracks it. And the 12-month rolling window catches you anyway.

Mistake four. Trusting a contractor who says “I can make the numbers work.” If a roofer is willing to lie to the city about square footage, they’ll lie to you about everything else. Walk away.

what a full code-compliant roof actually includes.

When the rule triggers and we do a full replacement, here’s what goes on the roof on a typical Plano or Frisco home:

• Tear off down to decking. All old shingles, felt, drip edge removed.
• Decking inspection. Anything rotted, delaminated, or thinner than 7/16” gets replaced. Average DFW home needs 2 to 4 sheets at $115 to $145 each installed.
• Drip edge on all eaves and rakes. Code-required, 26 gauge minimum.
• Ice and water shield in valleys, around penetrations, and 24” past the warm wall on the eaves.
• Synthetic underlayment across the deck. We use GAF FeltBuster or CertainTeed RoofRunner depending on the shingle.
• Starter strip on eaves and rakes.
• Shingles. We install CertainTeed Landmark Pro on most claim work in the $4.20 to $4.80 per sq ft range, or Landmark Solaris if the homeowner wants the cool roof rebate.
• Ridge cap matched to the shingle line. No three-tabs cut down to fake a ridge cap.
• New pipe boots, new vents, new flashing. Anything penetrating the deck gets new.

If you want the dollar math on your specific roof before you start the claim, our free roof cost calculator gets you within 10 percent in about three minutes.

Tear-off in progress on a North Texas home, with a couple of darker sheets showing rot from a prior partial patch.

how to handle this when you’re filing a claim.

Step by step, here’s what we tell homeowners:

1. Don’t sign anything from the carrier until a code-literate roofer has measured the roof and mapped the damage.
2. Get the adjuster’s scope in writing. PDF, email, whatever. You need the line items.
3. Compare scope to damage map. If their scope crosses 25 percent of roof area, the supplement is owed under R908.1.
4. Submit the supplement with the code citation, your roof measurement, and itemized code-required upgrades.
5. Wait 7 to 14 days for the carrier response. If they deny, request the desk adjuster’s review and cite the section.
6. Permit and install. City inspector signs off, you file for recoverable depreciation, carrier cuts the final check.

We handle steps 2 through 6 for every customer on a roof replacement claim. You don’t need to learn insurance code language on top of everything else.

frequently asked questions.

Does the 25 percent rule apply if I’m paying cash and not using insurance? Yes. The code doesn’t care who pays. It applies to any repair or replacement that touches more than 25 percent of roof area in 12 months.

What if my roof has two layers and only the top one is damaged? Texas doesn’t allow a second layer in most cases anyway. If you have two layers and damage triggers R908.1, both layers come off and you start fresh on the deck.

Can a roofer do a 24 percent repair to avoid the rule? Technically yes, if the damage is truly only 24 percent and the math checks. But we don’t recommend it on most claims. A 24 percent repair on a 12-year-old roof leaves you with mismatched shingles, partial underlayment, and a leak risk at every seam. You’ll be replacing the rest in 18 months anyway.

Does the rule apply to flat roofs and TPO? Yes. R908.1 covers all roof coverings, residential. Commercial TPO has its own threshold under the IBC but the principle is the same.

What if my city says they don’t enforce the 25 percent rule? Every Texas city we work in (Plano, Frisco, McKinney, Allen, Dallas, Fort Worth, Arlington, all of them) enforces R908.1 through the permit process. If a contractor tells you your city doesn’t enforce it, they’re wrong, and you don’t want them on your roof.

How long does the supplement process take? Typical timeline is 7 to 14 days from submission to carrier response. We’ve had supplements approved in 4 days and we’ve had ones drag to 30. The cleaner the documentation, the faster it moves.

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If your roof took hail or wind damage and you’re not sure whether you’re over or under the 25 percent line, call us at (214) 326-3106 and we’ll measure it for free. We’ll tell you straight whether the rule applies, what a code-compliant scope looks like on your house, and what your out-of-pocket should be. No pressure, no sales pitch, just the math.