Texas Windstorm Certification for Metal Roofing

If your property sits inside the 14 designated Texas coastal counties — Aransas, Brazoria, Calhoun, Cameron, Chambers, Galveston, Jefferson, Kenedy, Kleberg, Matagorda, Nueces, Refugio, San Patricio, Willacy — and the parts of Harris County inside the city limits of La Porte, Morgan's Point, Pasadena, Seabrook or Shoreacres and east of State Highway 146, you're in the Texas Windstorm Insurance Association (TWIA) service area. That means your metal roof has to pass a windstorm inspection and be certified by the Texas Department of Insurance (TDI) before any TWIA windstorm policy will attach to it, with limited exceptions. Outside those exceptions: no WPI-8, no policy, no claim coverage. This page is the practical version of what RISE Roofing does on every TDI-zone metal roof we install.

The WPI-8 in Plain English

The WPI-8 is TDI's certificate of compliance. TDI issues it to show the work meets the building code TDI has adopted for TWIA coverage (the 2024 IRC or IBC since April 1, 2026), after a TDI windstorm inspector or a TDI-appointed Texas licensed professional engineer has inspected the roof while it was being installed and approved all the inspections. A roof finished without those inspections takes a different route: a WPI-8-E, TDI's certificate for completed construction, issued after a Texas licensed professional engineer inspects the finished work. Once the certificate is issued, you can view and print it on TDI's website, and TWIA and insurance companies can look it up there. RISE keeps a copy in your project file.

The Three Inspection Windows You Can't Miss

WPI-8 inspections aren't a one-and-done at the end. To pass, the inspector has to physically observe each phase before it gets covered up:

1. Decking + fastening: 8d ring-shank nails, 6"/6"/12" pattern, plywood seams blocked. Once the underlayment goes down, this is unverifiable — so the inspection has to happen before underlayment.
2. Underlayment + ice/water: Synthetic underlayment with peel-and-stick self-adhering membrane at eaves, valleys, hip/ridge transitions, and all penetrations. Inspection happens before metal goes down.
3. Panel fastening pattern: Final inspection verifies that clip spacing on standing seam (or screw spacing on exposed fastener) matches the wind-uplift assembly tested for the rated speed.

Miss a window and TDI won't issue the WPI-8. We schedule all three with the inspector before the project even starts.

What We Install in Each Wind Zone

This table is RISE Roofing's own build spec, not a TDI rule. All of Brazoria County is inside TDI's catastrophe area; in Harris County, only properties inside the city limits of La Porte, Morgan's Point, Pasadena, Seabrook or Shoreacres and east of State Highway 146 are in it.

What Disqualifies a Metal Roof from a WPI-8

• Snap-lock standing seam used where the wind load is higher than its tested uplift assembly is rated for (in the beachfront zone we use mech-lock for the higher uplift assembly)
• Exposed-fastener panels installed with the manufacturer's "stock" 24" purlin spacing where the tested wind-uplift assembly calls for closer spacing (for beachfront wind loads we use 12–16" spacing)
• Unsealed panel-to-flashing transitions at chimneys, dormers, and skylights
• Substituted clip spacing without an engineer's letter on file

We've inspected metal roofs installed by other contractors that failed WPI-8 review and required full re-fastening — an expensive, avoidable problem.

The RISE Roofing TDI Process

We coordinate the WPI-8 inspections and paperwork on every TWIA-zone metal install: pre-construction engineering letter from a licensed Texas PE, scheduled inspections at all three windows above, and manufacturer wind-uplift documentation pulled and filed with the project. The fee is built into our project pricing — no surprise line items. TDI issues the WPI-8 once all the inspections are approved.

If you're in Galveston, La Marque, Texas City, Bacliff, Kemah, or the parts of Harris County in TDI's catastrophe area (La Porte, Morgan's Point, Pasadena, Seabrook and Shoreacres, east of Highway 146) and need a TDI-compliant metal roof, call (832) 345-9527. We'll walk the roof and send a written engineering pre-spec before quoting.