Information on Windstorm Certification

As of January 1, 2019, all new construction, roof replacements, major repairs, and other alterations must be inspected by an engineer appointed by TDI (Texas Department of Insurance) or a TDI inspector for a TDI WPI-8 OR by a Texas licensed engineer for a TWIA (Texas Windstorm Insurance Association) WPI-8-C. 

Who's Affected

TDI has designated the 14 coastal counties and some areas of Harris County to be in the catastrophe area.  Homeowners in these areas may not be able to obtain private insurance that covers windstorm and hail damage and must get coverage through TWIA.

Building to Code

To buy a TWIA policy, most homes and properties must have a certificate of compliance verifying that the structure meets applicable building codes and can withstand high winds and hail. There are two types of certificates of compliance:

  • A WPI-8 is issued by the Texas Department of Insurance for ongoing construction. These inspections can be done by an appointed Texas licensed professional engineer or TDI windstorm inspector while the work is underway.
  • A WPI-8-C is issued by TWIA for completed construction. These inspections can be done by a Texas licensed professional engineer.

For alterations like reroof (non-shingle), resides, new windows, new doors, new skylights etc, LynnEngineering will inspect that these products are installed in accordance with TDI product evaluations. If you have questions regarding product evaluations or if your product complies with requirements, contact our offices.

For reroofs utilizing asphalt shingles, choose shingles tested to meet the ASTM D 3161 Class F or ASTM D 7158 Class H requirements. The manufacturer should indicate compliance with these requirements on the shingle wrapper.

For new construction and additions, windstorm/structural engineering and design must be completed for ALL projects. LynnEngineering will engineer your project to meet the design requirements of the code. This must include a Windstorm Compliant Plan and Foundation Plan.

Inspection Requirements

Most new construction, roof replacements, major repairs, and other alterations require an inspection and certificate of compliance. Items that do not require an inspection can be found here: PDF Download.
During the inspection process, LynnEngineering will verify that all construction is in compliance with TDI product evaluations, manufacturers approved installation, and/or engineered construction drawings.

New Construction Inspection Process

  • Foundation – LynnEngineering must inspect all aspects of the foundation system. This includes, but is not limited to, rebar sizes and spacings, concrete beam depth, beam location, vapor barrier, pier depth, timber piling depth, timber stringer/beam sizes, and all bolted connections.
    • Foundations must be poured and piles set in accordance with an engineered stamped foundation plan.
  • Framing- LynnEngineering must inspect all framing members used to resist the gravity, lateral, and uplift loads experienced by the structure. This includes but is no limited to, floor joist, ceiling joists, rafters, studs, headers, wall sheathing, roof decking, and beams.
  • Clips, Straps, Hold-downs – LynnEngineering must inspect all clips, straps, and hold-downs are installed in accordance with manufacturer’s installation requirements and are consistent with LynnEngineering Windstorm Compliant Plan.
  • Components and Cladding – LynnEngineering must inspect the installation of all windows, doors, siding, roofing, and any other products that will be attached to the structure and verify installation is consistent with TDI product evaluations.
  • Exterior Mechanical Equipment – LynnEngineering must inspect that all AC condensing units, generators, and any other mechanical equipment that may be connected to the structure are anchored to with stand 100lb of uplift
  • Wind Borne Debris Protection – LynnEngineering must verify that all glazed openings are protected from wind borne debris.