If your property sits inside a designated Texas catastrophe area, you need TDI-listed wind-rated materials and a WPI-8 certificate to keep your TWIA windstorm insurance eligible. Most new roofs, replacements, and major repairs trigger this requirement; patch jobs under a small area that skip the decking usually don’t. Check your address on the state’s windstorm map, then confirm your contractor plans to document the install to TDI standards from day one.
TL;DR:
- Homes in designated Texas catastrophe areas require TDI-listed wind-rated materials and a WPI-8 certificate for TWIA coverage, especially after April 1, 2026.
- The need for a WPI-8 depends on the precise address, tier classification, and exposure zone, not just county or city location, requiring careful map and wind speed verification.
- Shingle wind ratings from ASTM tests must be paired with appropriate installation methods, including underlayment, fastening, and accessories, to meet TDI standards.
- Documentation, such as photos of the deck and underlayment taken before shingles are installed, is critical to prevent certification delays or failures.
- Contracting with experienced professionals who coordinate inspections beforehand and provide proper documentation reduces costs and ensures compliance.
Table of Contents
- Roof Wind Ratings in Texas: TDI, TWIA, and the WPI-8 Requirement
- Do You Need a Windstorm Certificate for Your Property?
- How Wind Ratings Translate to Materials and Installation
- Your Checklist for Getting a WPI-8 Without Delays
- Field Notes on Windstorm Certification Pitfalls
- Getting Wind-Rated Compliance Right the First Time
- Sources
- FAQ
Roof Wind Ratings in Texas: TDI, TWIA, and the WPI-8 Requirement
Texas doesn’t leave wind resistance to guesswork along the coast. Starting April 1, 2026, the Texas Department of Insurance requires new construction and major roof repairs in designated catastrophe areas to comply with the 2024 International Residential Code or 2024 International Building Code to qualify for coverage through the Texas Windstorm Insurance Association. The mandate applies to every construction application submitted on or after that date, which means roofs permitted under older code cycles won’t automatically carry forward their eligibility once you touch them again.
TWIA exists because private insurers often won’t write windstorm coverage in the highest risk coastal zones. For a lot of homeowners in those counties, TWIA is the only practical option, so falling out of compliance isn’t a minor paperwork issue. It can mean losing access to coverage altogether.
That’s where the WPI-8, or Windstorm Certificate of Compliance, comes in. It’s issued after inspection by a TDI-appointed windstorm inspector or a Texas-licensed professional engineer, and it’s the document TWIA and most coastal insurers actually check before binding a policy. You’ll typically need one for:
- New home or commercial construction
- Full roof replacements
- Substantial repairs that expose or replace decking
- Additions that alter the roof structure
Small repairs under 100 square feet that don’t touch the decking are generally exempt. But “generally” is doing real work in that sentence. If your contractor isn’t sure which side of that line your project falls on, get it in writing before work starts, not after.
Do You Need a Windstorm Certificate for Your Property?
Whether you need a WPI-8 depends less on your city and more on your exact address. TDI’s Windstorm Inspection Program covers the 14 first-tier coastal counties, plus a carved-out slice of Harris County east of Highway 146. That Harris County boundary trips up a lot of homeowners who assume their whole county is either in or out.
Here’s how to confirm where you stand:
- Pull up the TDI windstorm map and search your street address, not just your zip code or county name.
- Note whether you’re in Tier I (closer to the coast, higher design wind speeds in some areas) or Tier II (inland catastrophe counties with somewhat lower thresholds).
- Cross-check the required basic wind speed for your parcel using the ASCE 7 Hazard Tool, which ties directly into the wind speed tables the 2024 IRC and IBC reference.
- If you’re near a tier boundary or a county carve-out line like Harris County’s, verify with TDI directly rather than trusting a neighbor’s paperwork or a contractor’s assumption.
Proximity to the coast doesn’t just affect whether you need a certificate. It changes which shingle class and fastening pattern satisfy the code at all.
How Wind Ratings Translate to Materials and Installation
Shingle wind ratings come from two ASTM tests, and knowing which one governs your project matters more than most product labels let on. ASTM D7158 tests shingles under simulated wind uplift and sorts them into Class D (up to 90 mph), Class G (up to 120 mph), and Class H (up to 150 mph). ASTM D3161 uses a different wind tunnel method and produces its own classes, with Class F built for the highest wind exposure. For coastal Texas properties, TDI guidance points toward shingles tested to ASTM D3161 Class F or ASTM D7158 Class H, paired with the manufacturer’s published high-wind installation instructions.
A wind rating on a shingle wrapper means nothing if the rest of the assembly doesn’t match it. TDI and the IRC/IBC roof-assembly chapters treat wind resistance as a system, not a single product:
- Underlayment: No. 30 felt or an ASTM D1970 self-adhering underlayment is often required at 140 mph and above, with taped or self-sealing seams in the highest exposure zones.
- Fastening: Many high-wind installations require a 6-nail pattern per shingle instead of the standard 4, using corrosion-resistant nails with proper penetration into the deck.
- Starter strips and flashing: Manufacturer-specified starter courses and flashing details are part of the tested assembly, not optional extras.
- Accessories: Skylights and roof vents need their own published wind resistance data under ASTM E1886 and E1996 when impact and cyclic pressure resistance apply.
Before you approve materials, ask your contractor to check the product against TDI’s approved listings and pull the manufacturer’s approval letter if the product line isn’t clearly listed. Not every shingle rated Class H is automatically TDI-acceptable for Texas seacoast use. Manufacturers issue specific “Seacoast” approval letters tied to a documented installation method, and the installed fastening pattern has to match what that letter describes.
Pro Tip: Ask for the manufacturer’s approval letter before the crew starts, not after the inspector asks for it. A letter that shows up two weeks into the job rarely matches the actual nailing pattern already on your roof.
Your Checklist for Getting a WPI-8 Without Delays
Certification failures almost never come from bad materials. They come from missing paperwork on a roof that already looks fine. Here’s the sequence that keeps a project on track:
- Before work starts: Confirm your zone on the TDI map, select TDI-listed materials rated for your tier, and ask your contractor exactly how they’ll document the install, including photos, product lot numbers, and inspector scheduling.
- While the roof is exposed: Require photographs of the sheathing, underlayment, and flashing before shingles go down, along with verification of nail type, count, and penetration depth. Inspections have to happen while elements are still visible; once shingles cover the deck, there’s no way to verify what’s underneath.
- At inspection: Schedule the WPI-8 inspection before the roof gets its final covering, and collect the WPI-2-BC inspection form along with the final WPI-8 or WPI-8E certificate.
- After completion: Store the certificate somewhere permanent. You’ll need it for insurance renewals and for any future home sale, since buyers in catastrophe-area counties routinely ask for it.
Skipping step two is the single most common reason certification stalls. A contractor coordinating with a TDI-appointed inspector or a licensed engineer while the deck and underlayment are still visible avoids the far more expensive alternative: tearing into a finished roof to prove what’s already installed.
Field Notes on Windstorm Certification Pitfalls
I’ve watched otherwise solid roofs fail certification for reasons that had nothing to do with the shingles themselves. Incomplete documentation is the repeat offender: no photos of the underlayment, no lot numbers, no record of nail count before the deck disappeared under shingles. A close second is scheduling the inspection after the final layer goes on, which forces an inspector to guess at what’s underneath instead of confirming it.
Contractors who protect your insurability coordinate the inspection timing before the crew closes up the roof, use only TDI-listed products with matching manufacturer letters, and keep a paper trail an adjuster can’t dispute later.
— Mark Griffith
Getting Wind-Rated Compliance Right the First Time
Most roofing companies can install a shingle. Fewer can hand you a documentation packet that actually clears TWIA review on the first pass, and that’s the gap that costs homeowners money and time. Griffith roofing has spent over two decades in the Dallas-Fort Worth Metroplex handling roofs where compliance paperwork matters as much as the shingles themselves, and every project starts with a complimentary roof inspection to confirm what your property actually needs before any material gets ordered.
When you hire Griffith roofing for a replacement or new installation, expect photo documentation of the deck and underlayment, coordination with the inspector while your roof is still exposed, and materials pulled from TDI-listed product lines rather than whatever happens to be in stock. If a storm already did the damage, our storm damage restoration team also handles the insurance claims assistance side, so the paperwork keeps pace with the repair. Reach out for a roof inspection and we’ll tell you plainly whether your existing roof would pass a WPI-8 review today, or what it would take to get there.
This article is general information, not a substitute for advice from a qualified financial advisor. Consult a qualified financial professional about your own circumstances before acting on anything here.
FAQ
What Is a WPI-8 Certificate?
A WPI-8 is a Windstorm Certificate of Compliance confirming a roof or building meets Texas windstorm construction standards. It’s issued after inspection by a TDI-appointed inspector or a licensed Texas engineer and is typically required for TWIA eligibility.
Do All Roof Repairs Need a Windstorm Inspection?
No. Small repairs under 100 square feet that don’t involve decking work are generally exempt from windstorm inspection. Full replacements, new construction, and repairs that expose the deck almost always require one.
Which Shingle Class Do I Need for Coastal Texas?
TDI guidance recommends shingles tested to ASTM D3161 Class F or ASTM D7158 Class H for coastal exposure, paired with the manufacturer’s specific high-wind installation instructions. Inland catastrophe counties may qualify with a lower class depending on the site’s design wind speed.
How Much Does Griffith Roofing Charge for a Wind-Rated Roof Replacement?
Pricing depends on the property, material choice, and wind-rating tier required for the address, so Griffith roofing doesn’t publish a flat rate. A complimentary roof inspection gets you an exact quote based on your specific compliance needs.
What Happens if My Roof Fails to Get a WPI-8?
Without a valid WPI-8, your property may become ineligible for TWIA windstorm coverage, which is often the only windstorm insurance option in first-tier coastal counties. Correcting a failed certification after the roof is closed up usually costs more than getting the documentation right during installation.
