Texas Department of Insurance Windstorm Inspection Program

Are you involved with a building project along the Gulf Coast of Texas in which metal roofing or siding is involved? If so, obtaining a building permit may be subject to compliance with the Texas Department of Insurance (TDI) Windstorm Inspection Program. Here is some information that can help.

What is the TDI Windstorm Inspection Program?

In 1987, the Texas Legislature enacted HB 2012 with a requirement to mitigate losses to structures due to hurricanes along the Texas Gulf Coast. On January 1, 1988, the Texas Department of Insurance (TDI) began administrating the Windstorm Inspection Program in support of this legislation. The program is centered in Austin, with four other field offices also located along the Gulf Coast.

Where does the TDI Windstorm Inspection Program apply?

The Windstorm Inspection Program applies to all commercial and residential structures located primarily along the Gulf Coast of Texas. TDI has designated specific areas as catastrophe areas, also known as Texas’ First Tier Countries. The affected countries include Aransas, Brazoria, Calhoun, Cameron, Chambers, Galveston, Jefferson, Kenedy, Kleberg, Matagorda, Nueces, Refugio, San Patricio, Willacy and certain cities east of State Highway 146 in Harris County (La Porte, Morgan’s Point, Pasadena, Seabrook, Shoreacres).

Designated Catastrophe Areas
Designated Catastrophe Areas

What is the Texas Windstorm Insurance Association?

The designated catastrophe areas often use Texas Windstorm Insurance Association (TWIA) as the insurer of last resort for the wind and hail portion of their building insurance. To qualify for wind and hail insurance through TWIA, all new structures plus any alterations, additions, or repairs to existing structures (including re-roofs or roof repairs) located in the designated catastrophe areas must be constructed and inspected according to the building specifications adopted by TDI.

How are Building Permits Affected?

All building work needs to meet the requirements of the adopted building codes in Texas (currently the 2006 version of the International Building Code and the International Residential Code). However, in addition to the codes, the TDI requirements must also be complied with in the designated countries. This is similar to other parts of the country that experience severe weather events (e.g., Dade County, Florida) where additional requirements above the code have been instituted for safety reasons. At the time of building permit application, evidence will need to be shown of TDI compliance in design documents; therefore, many times the local TDI office is contracted first and an application is submitted (Form WPI-1). Then, during construction, a TDI certified inspector (usually an engineer) will inspect the work, as will the regular building inspectors. Compliance will need to be shown with the TDI requirements (Form WPI-8) in order to obtain final sign off and a Certificate of Occupancy.

What Building Products are Approved for Use?

In order to be compliant with TDI standards, building products must be independently tested and shown to be able to withstand different levels of severe weather. For products like metal roofing and siding, the testing needs to include the method of attachment and the substrate type (metal, wood, etc.). Product evaluations are available by product type (such as “Exterior Coverings” for metal siding or “Roof Coverings” for metal roofing) and then by manufacturer all by either contacting a local TDI field office or on TDI’s website: www.texas.gov/wind/prod/index

For more information on this program visit http://www.tdi.texas.gov/wind/index.html or email [email protected]. To find out more about metal roofing and siding products that meet the severe weather requirements, contact your local MBCI representative.

 

Choosing the Right Type of Standing Seam Roof (SSR)

When it comes to specifying standing seam roofs, one type doesn’t fit all. While a standing seam metal roof system can be one of the most durable and weather-tight roof systems available in the industry, its benefits can be negated if you fail to understand the details in application parameters of the specific system. Do your research, though, and for your next design that requires an aesthetically pleasing and structurally sound metal roofing system, you can choose with confidence the standing seam metal roof system that suits your project to a tee.

How to identify a good standing seam roof system

A good standing seam roof system is one that can satisfy both the project’s specific design criteria and adhere to building code standards. Standing seam profiles can include those that are utilitarian or architectural in nature, are of numerous widths and profiles and have varying seam joinery (e.g., snap or field seamed).

Why specify a standing seam metal roof system

When properly installed, standing seam metal roof systems are an extremely effective and long-lasting material choice. Key advantages include:

  • Weather-tight roofing system
  • Can be engineered to withstand high winds (150 mph and higher)
  • Class A Fire-resistance rating from UL
  • Class 4 Impact-resistance rating from UL
  • Long service life—up to 60 years
  • Lightweight
  • Special clips designed to accommodate thermal roof expansion and contraction and various thicknesses of fiberglass insulation

Matching the roof system to the project

In basic terms, there are four unique styles of metal standing seam panels: Double lock seam, symmetrical seam, one-piece snap-lock interlock and two-piece snap-lock interlock. These styles can be further delineated by seam shape or profile, i.e. trapezoidal rib, vertical rib, square rib and tee rib. The choice of the rib profile, as well as the rib spacing is generally an aesthetic preference of the designer. Knowing which style will best suit a given situation will help ensure a successful installation.

Popular Standing Seam Metal Panels

Double Lock Standing Seam
Shown: MBCI Double-Lok®

One-Piece Snap Lock Interlock Standing Seam
Shown: MBCI LokSeam®

Two-piece Snap Lock Interlock Standing Seam
Shown: MBCI Craftsman™

Some criteria to consider are roof slope, roof run (distance from eave to ridge), weather conditions (such as ice or snow) and architectural features, i.e. hips, valleys, dormers, parapet walls, etc.

For instance, if your project has a roof slope of 1/2:12 you will need to ensure the product being installed is approved for this low pitch. In this case, you would likely use a “double lock” or mechanically “field-seamed” panel. You also want to ensure that all details are able to provide for a weather-tight seal even if temporarily submerged during a heavy rain. Field-seamed panels are also the best choice in areas that experience heavy ice and snow.

Additionally, it is imperative to recognize complicated design details that should be carefully specified and reviewed regardless of the roof slope. Design conditions that require special attention include: roof transitions, dead valleys, dormers, eave offsets, ridge offsets and offsets in parapet walls.

It cannot be overstated that you should always consult a metal roofing manufacturer about the capabilities of the standing seam metal roof system, including what warranties are available, prior to specifying it.

Browse the standing seam product manual for more information.

Design and testing

Familiarize yourself with wind uplift testing as prescribed by Underwriters Laboratories (UL-90 – 580 Test) and ASTM E-1592.

For more information on standing seam metal roofing, visit MBCI’s CE course on the topic: http://www.bdcuniversity.com/standing-seam-metal-roofing

Sustainability Begets Resiliency…In Practice

McMahaon Centennial Complex, Cameron University

Sustainability is the buzzword started by USGBC that is pushing us to design and build environmentally friendly buildings.  And that’s a good thing.  However, from a practical—and roofing—standpoint, what we can most readily do with roofs is design them to be resilient.  Roof system resiliency is the tangible aspect of sustainability that the “regular” population can get their heads around.  Resiliency—the ability to bounce back—is understandable.

Loosely speaking, a resilient building can withstand an extreme weather event and remain habitable and useful.  It follows that a resilient roof system is one that can withstand an extreme weather event and continue to perform and provide shelter.

What makes a metal roof system resilient?  It needs to be tough and durable, wind and impact resistant, highly insulated and appropriately reflective, and perhaps be a location for energy production.

An extreme weather event typically means high winds.  A resilient metal roof system needs to withstand above-code wind events.  Remember, codes are minimum design requirements; there is nothing stopping us from designing metal panel roofs above code requirements!  If a building is located in a 120 mph wind zone, increase the design/increase the attachment as if it were in a 140 mph wind zone.  And, very importantly, increasing the wind resistance of the edge details is critical to the wind resistance of a roof system.

Toughness is important.  Increasing the thickness of a metal panel roof system increases resistance to impacts and very likely increases service life (of the metal panel, at least).  Tough and durable seams are important, too.  A double-lock standing seam is one of the best seam types for metal roofs.  A little bit of extra effort at the seam can go a long way for durability, weatherproofing, and longevity.

Highly insulated and appropriately reflective are also traits of resiliency.  High R-value means less thermal transfer across the roof assembly.  Two layers, staggered or crisscrossed, provide a thermally efficient insulation layer.  Using thermal breaks between the metal panels and the metal substructure adds to the thermal efficiency.  Reflective roofs help reduce heat transfer through the roof assembly.  The effectiveness of a roof’s color and reflectivity to save energy depends on many items, such as location, stories, and building type.

Enhanced wind resistance, improved impact resistance and toughness, high R-value, and reflectivity and color are passive design elements that increase the resiliency of a building’s rooftop.  And let’s not forget that rooftop energy production can provide electricity to critical components of a building, such as a freezer section of a grocery store.  Hurricane Sandy put resiliency on the public radar; resilient buildings are here to stay.

Find a sales representative