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| The Basics | Would your home survive a natural disaster?
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Don't count on building codes. The fate of your home -- and your family -- may depend on a few simple methods of strengthening its structure against winds, fire, quakes and other ravages of Mother Nature.
By Liz Pulliam Weston
If youve lived through a natural disaster, or even watched the aftermath on television, then youve probably seen the lone soldiers -- houses that stand intact when everything else in the neighborhood has been blown, shaken or burned to the ground.
Sometimes its just random chance that saves these homes. Often, though, these survivors are built differently -- and better -- than the ones around them.
I saw this firsthand when I lived in Laguna Beach, Calif., where a 1993 wildfire destroyed more than 400 homes. The heat was so intense that refrigerators melted into puddles of steel and stark chimneys were all that remained of many hillside homes. Yet a few houses with fire-resistant roofs, siding and construction techniques survived without so much as a cracked window.
Codes can fall short
Disasters such as fires, earthquakes and windstorms often prompt upgrades in building codes as people become more aware of the dangers posed by Mother Nature. But the reality is that even the most up-to-date building codes can still fall short of protecting your home against major catastrophes. The situation is even worse for older homes, which were often built before engineers and builders paid much attention to strengthening homes against disasters.
We refer to building codes as the minimum acceptable standard, said Wendy Fontaine, spokeswoman for the insurer-supported Institute for Business and Home Safety which promotes better building techniques. Building codes are designed to be an average that can apply to all types of construction -- not a reflection of the cutting edge in home design.
Most building codes in tornado-prone states, for example, require homes to withstand winds up to 70 miles an hour, Fontaine said. But the average tornado blows through with wind speeds of 200 mph and up.
Invest a few dollars in the right places
Likewise, many homes in earthquake-prone areas arent anchored to their foundations, said earthquake researcher Mary Comerio, although such tethering is one of the most effective ways to prevent major structural damage or collapse. Comerio is a professor at the University of California, Berkeleys Department of Architecture and author of Disaster Hits Home, a book on earthquake damage.
You dont have to accept the risk that your castle could be reduced to kindling or ashes. For a few dollars more in construction costs, say Fontaine and building experts, you can fortify your house to withstand all but the worst catastrophes. For example:
- If youre building a 2,000-square-foot home, the extra materials and labor needed to fortify it against most natural disasters typically would cost less than $4,000, Fontaine said. At most, the techniques would add about 10% to the cost of building an average home.
- Retrofitting an existing house can be more expensive. Anchoring an existing house to its foundation can cost $3,000 or more, for instance. But if youre planning a remodeling project or need to replace your roof, you can incorporate many fortification techniques without substantially increasing your building costs.
- Speaking of remodeling, you also should be sure that your plans dont wind up making matters worse. Remodels that remove interior walls, add upper stories or insert windows or doors to once-solid walls can significantly weaken a home and make it more vulnerable to disaster damage.
Something for everyone
And lest you think fortification is something only Californians and Floridians need to think about, think again:
- Earthquakes: Everybody who lives west or just east of the Rockies is in earthquake country. Other major seismic zones include Alaska, New England and the New Madrid fault area along the Mississippi River.
- Hurricanes: Coastal states from Texas up through Maine are most at risk, as is Hawaii.
- Tornadoes: Kansas, Oklahoma and Texas are prime tornado targets, but tornadoes have shown up in most states at one time or another. Tornado Alley describes an area of the country that runs north from Texas to eastern Nebraska and northeast to Indiana.
- Wildfires: Once again, just about every state has experienced significant wildfires in the past century. Youre more at risk the closer you live to wilderness areas or open land.
So what should you do if you want to protect your home? Engineering studies of homes after Hurricane Andrew, the Northridge and Loma Prieta earthquakes and various wildfires show that the many of the same techniques can help in a variety of disasters:
Build simply. The safest shape is a one-story box thats anchored to its foundation. The more stories, angles and overhangs you add, the more opportunities you give Mother Nature to tear your home apart.
Oversize windows, sliding glass doors, large skylights and garage doors that are more than eight feet wide are particular liabilities. Big openings tend to weaken walls, making them more likely to fall apart in a shaker. Wildfires can shatter windows, glass doors and skylights, allowing firebrands to enter the home and ignite the interior. Hurricanes and tornadoes can blow through windows and doors and then blast the roof off from inside.
Windstorms also can use decks, bumped-out windows and other overhangs as a kind of pull-tab to rip off a homes walls or roof. These protuberances are vulnerable in a firestorm as well, since the flames collect below and send super-heated gases upward, drying out the structures above and making them more likely to catch on fire.
That doesnt mean you have to give up on interesting features, but you should take precautions:
- Enclose the area beneath decks and overhangs.
- Use impact-resistant glass and doors, along with shutters, in windstorm areas. Tempered glass is a good idea where wildfires are a concern.
- Strengthen garage doors, especially if theres a living area above it.
- Consider a series of smaller windows instead of one large one, or replace a sliding glass door with a French door made with impact-resistant glass.
Tie it together. Most fortification simply involves anchoring one part of the home to another with extra fasteners, straps or bolts. Strengthening the connections between the roof and the walls, and between the walls and the foundation, will help your home survive both windstorms and earthquakes.
Your roof should be anchored to the walls with metal clips and straps, not just nails. Likewise, the walls should be properly tethered to the foundation. If your home has more than one story, each storys framing should be securely connected to the level below.
And when it comes to using nails, the more, the merrier. The institute recommends using more nails in more concentrated patterns than is common in most construction, and using nails with ringed rather than smooth shanks to increase their holding power.
Secure the perimeter. The type of landscaping you choose and the materials you use can have a big impact on how well your home survives a disaster:
- Remove dead and damaged trees to reduce potential fire and wind damage.
- Dont plant trees next to your house, and keep limbs of existing trees trimmed away from your roof.
- Use soft mulch materials like shredded bark, which does much less damage in a windstorm than loose stone or gravel.
- In wildfire areas, clear brush and undergrowth from around your home and choose fire-resistant plants. Remove plants that catch fire easily, such as oil-laden eucalyptus trees.
You may reap some economic benefit from strengthening your home. Homes with obvious mitigation measures, such as storm shutters in hurricane-prone areas, tend to sell at a slight premium, according to a study by Texas Tech University and Oklahoma City University. Your insurer also may give you a discount for certain measures.
The real benefit, however, may be peace of mind. The stronger your home, the safer your family is inside of it. As Fontaine says, If theres even a one in a million chance of my home being destroyed, and the technology is there to build my home more strongly, Id want to do that.
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