How To: Make Your Home Storm-Resistant
The right materials and proper installation can strengthen your home against the most severe weather.
No matter where you live, chances are there is some kind of weather or geologic condition, such as hurricanes and high winds, wildfires and floods, that requires extra attention in your home’s construction. The two areas that can make the biggest difference in making your home storm-resistant are the roof and the windows. That’s great news for homeowners because they can be addressed during both new construction and renovation.
“We usually start at the roof [to make a home storm-resistant],” says Tim Reinhold, director of engineering and vice president of the Institute for Business & Home Safety (IBHS), a Tampa, FL-based nonprofit organization sponsored by insurance companies to promote hazard-resistant construction. “When you have enough damage to have a claim, 90 percent of homes have roof damage.”
Whether you’re in a high-wind or earthquake-prone area, the Institute recommends attaching roof sheathing to the trusses with ring-shank nails, which have a spiral feature in the shank and can increase the holding power of the nail by 50 to 100 percent. As with any construction materials, they only work if they’re installed correctly. Space the nails six inches apart, Reinhold says. Over the roof decking, you need a strong underlayment so that if the top layer of roofing material (typically shingles or tiles) comes off, you still have a layer of protection. Whether you use shingles, tile, or metal for the top layer, pay careful attention to installation. Otherwise, tiles and metal sheets can become dangerous missiles. Shingles can tear off, leaving the roof exposed to further damage.
“We use individual concrete tile that is foamed in, mortared in, and screwed in,” says Marieanne Khoury-Vogt, town architect for Alys Beach, a coastal town in the Florida Panhandle that has constructed every building to IBHS’s “Fortified for Safer Living” standards, which exceed Florida’s rigorous code for building in coastal areas. “Then we have another very thin layer of grout that fills in between the tiles, a cementitious film, and paint on top of that.”
With an architectural style inspired by the island homes in Bermuda, the buildings in Alys Beach are masonry, which offers significant strength against wind and water. The roofs of the Alys Beach buildings all have very shallow eaves, which gives hurricane winds little to pull against. Finished floors are two feet above grade to reduce the risk of flooding.
The decision to build an all-masonry community happened before the devastating 2004 hurricane season, she says, but it “made a difference in people wanting to invest here. It’s a huge relief to people. We do feel very, very good about the ‘Fortified’ standards.”
Windows and Doors
The use of impact-rated windows and doors—designed to meet weather conditions in high-velocity hurricane zones—relieves owners from having to board up windows and doors, “and you get the same insurance breaks” as owners who have hurricane shutters, Khoury-Vogt says.
If impact-rated windows and doors are beyond your budget, Reinhold says, a less expensive alternative is to combine windows and doors that meet the local design pressure rating with a protective system, such as hurricane shutters.
“Old standard windows are rated at 30 to 35 pounds per square foot,” he says. “That’s good for the middle of the country, but not hurricane zones. Closer to the coast, the rating will be 40 to 45 pounds per square foot. In a taller building sitting on the coast, it could be pushing 80 pounds per square foot.”
Fires and Floods
Cement tile, clay tile, and slate roofs, along with stucco and brick exteriors, are not only great for protecting a house from wind-driven rain and storm debris; they’re also excellent fire-retardant materials. In California, the annual Santa Ana winds can gust to hurricane force and contribute to the area’s other major risk: wildfires. While no house is fireproof, those fire-retardant materials play a key role in reducing the risk, says builder-remodeler Gordon Gibson, president of Gordon Gibson Construction in Santa Monica, CA.
For fire protection, homeowners must also pay close attention to the types of plants used in landscaping and how far they’re situated from the houses. Landscaping and site grading are also important for preventing damage during floods that can race through the canyons in southern California, Gibson says. The grade should slope away from the house, and the finished floor of the house should be six inches higher than any adjacent grade. When landscaping is planted too close to the house, growth over time can bring the grade above the level of the house. To help prevent water intrusion, Gibson also uses a waterproof membrane that extends from the foundation to the wood frame.
“Keep trees planted away from the house; keep the tree canopy two feet from the house; and don’t let any vegetation touch the house,” Gibson says. “That’s the best way to prevent a lot of damage that happens.”
For more tips on making your home as safe as possible before a storm disaster hits, visit the IBHS Web site, DisasterSafety.org. For an interactive guide to protecting your home from wildfires, visit www.firewise.org.
Some products are designed to be used only when danger is threatening. Here are a few to check out:
Shutters can run the gamut from sheets of plywood to sophisticated, motorized systems. The Disaster Safety web site has instructions on how to make and install your own.
Sandbags are the traditional method of keeping floodwater out of a house. The DoorDam, made by Presray Corp., is an expanding mechanism inside a neoprene sheath that extends across doorways to block flood waters as high as 32 inches. It weighs about the same as one sand bag, and you can reuse it year after year. Visit the DoorDam web site for details.
Garage door bracing systems
Many garage doors can buckle during high-wind conditions. Check with your garage door manufacturer to see it if offers a vertical bracing system, or ask your home builder to recommend one. Generic kits also are available at many home improvement stores. Or, you can make your own wood columns. Instructions are on the DisasterSafety.org web site.
Portable water pumps
These pumps are designed to draw water from a swimming pool to spray on your roof and exterior walls, which gives a fire less fuel to burn.
Helpful for all types of severe weather situations, generators are widely available. They should always be used outdoors to avoid the risk of carbon monoxide poisoning in the home.