Building a Storm-Resistant Home

Combat wind damage by including the following in your next project:  1) Impact-resistant doors;  2) Reinforced garage doors or single-car openings;  3) Hurricane shutters or impact resistant glass;  4) Windows with high-performance glass.

"People do think about safety a little bit more around here," says Mike Romig, president of Tarpon Coast Development in Osprey, Fla., which sits along the hurricane-prone coast of the Gulf of Mexico. (Learn more about about Mike Romig's storm-resistant building techniques on www.pathnet.org,)

Tarpon builds homes designated as Fortified...for safer living, a program operated by the Institute for Business and Home Safety, to increase the company's homes' resistance to natural disasters.

"Our goal is to exceed the most stringent Florida code for barrier islands and the Florida Keys," Romig says. "We are building in a 130 mph wind zone, but our construction goes beyond the requirements of the 150 mph wind zones."

Romig builds with precast concrete walls and several techniques recommended by the Partnership for Advancing Technology in Housing (PATH) to protect his homes from high-wind events.

The 2003 International Residential Code requires houses to meet storm-resistant standards where wind speeds equal or exceed 110 miles-plus per hour. This typically happens along the East Coast and the Gulf of Mexico, but there are plenty of benefits to applying wind-resistant technologies in tornado-prone areas as well.

2006 brought 23 tornadoes with estimated wind speeds of more than 158 mph, according to the National Climatic Data Center. The Midwest, South, and Southeast are the most susceptible. FEMA's Project Impact program recommends builders in high-risk areas follow many of the same guidelines as they do for hurricane-resistant construction.

PATH recommends the following for such construction. Remember to check with code officials to confirm the appropriate design decisions for your area:

1. A low-profile house is inherently less vulnerable, so a one-story home is less likely to experience wind damage than a two-story.
2. A home with a hip roof is less vulnerable than a gable roof home. Very low-sloped roofs increase uplift; steeply sloped roofs create lateral wind loads. The ideal slope is moderately pitched below 6/12 and greater than 4/12.
3. For roof sheathing installation, consider 8d nails spaced at no more than 6 inches on center. Ring shank nails improve wind resistance for a small cost. Sheathing should be a minimum thickness of 19/32 inch for added strength.
4. Use baffled ridge and soffit vents to minimize the number of roof penetrations, which are vulnerable in high winds. Baffled vents slow airflow and prevent wind-driven rain from entering the attic through the ridge vent.
5. Wrap hurricane straps over the top of the roof truss or rafter. Strap each part of the wall assembly together or anchor it from the foundation to the roof to provide a continuous load path, connecting the roof to the foundation for stability.

This detail above shows proper application of cement in the insstallation of typical high-impact, and wind-resistant shingles. This detail shows the proper installation of ridge shingles in high wind areas. This details the proper placement of roofing nails on a shingle installation.

A strong, durable roof is the first line of defense against water infiltration. Water, rather than wind, is the cause of most storm-related damage. PATH's Tech Set on storm-resistant roofing highlights several ways to will keep water out:

1. Improve the overhang design by extending the fascia board to end below the underside of the soffit. Increasing the fascia board size from a 1 by 4 to a 1 by 6 creates a drip edge so that buffeting winds do not drive the rain across the soffit surface and into the eaves. Limit vent perforations to the outer edge of the soffit to reduce the area where moisture can enter.
2. On the roof, even if coverings and underlayment blow off, decking can still act as a barrier if the seams have been taped with a self-adhering asphalt/rubber tape. An alternative is laying a peel-and-stick roof membrane over the roof deck.
3. Install flashing wherever there is a change in surface plane or cladding material. Flashing not only channels water runoff during storms, it also provides a second level of protection from water intrusion.
4. When flashing roof edges, use a shingle starter strip or a self-adhering ice and water barrier membrane. Do not use an upside-down shingle as the starter strip.
5. Top the roof off with wind- and impact-resistant asphalt shingles. Standing-seam metal roofs are also a good choice for storm resistance. A metal roof will raise the price $10,000—15,000, Romig says, but you can't beat the durability. Once it's installed, it will last up to 50 years.

Even properly designed new homes remain susceptible to severe damage if wind and water penetrate the home. PATH's Tech Set for wind-resistant openings offers several solutions:

1. Impact-resistant doors withstand wind-born projectiles. Read the manufacturer's installation instructions because how you attach it is critical. Remember that outward-swinging doors reduce the likelihood of system failure in high wind.
2. Garage doors, especially two-car garage doors, often fail in storms due to their large size and relatively weak materials. Some garage doors are now constructed, tested and rated for impact and wind resistance. They cost about $200 to $300 more than the standard door.
3. Storm-resistant shutters are made of wood sheathing, acrylic or steel panels and are fastened to window frames. To qualify as storm resistant, they must resist a 2 by 4 flying at 35 mph.
4. Impact-resistant windows work well on their own or with shutters. When struck, the glass may crack or shatter, but the fragments stay in place.

Author Information

Scott T. Shepherd writes about better building practices on behalf of the Partnership for Advancing Technology in Housing. PATH is administered by the U.S. Department of Housing and Urban Development. Learn more at www.pathnet.org