Hurricanes are one of nature's most destructive forces, as witnessed in 2005 when Hurricane Katrina pummeled the Gulf Coast. FEMA estimates that Katrina killed over 1,300 people, displaced 450,000 people, and wrecked over 300,000 single-family homes throughout Louisiana and Mississippi. Most of the havoc caused by Katrina was flood-related, due to levee failures in New Orleans.
Wind and water are the ingredients for disaster during any hurricane. Wind puts external forces on the walls of a home, causing a range of cosmetic and performance problems. Wind can lift the roof off a home, break the connections between levels of a home, and cause walls to slide off the foundation. All of these problems open the home up to air, moisture, and water infiltration. In the case of Katrina, the most common type of structural damage occurred when roof sheathing panels weren’t properly attached to the supporting framing. Without sufficient attachment, the roof lifts off a home and allows water to enter.
Hurricane Katrina demonstrated the need for better disaster preparedness. Many of the communities that were heavily impacted by Hurricane Katrina had not adopted up-to-date building codes that incorporate flood and wind protection or had no building codes at all. Builders are now working to improve the performance of homes, so that they can withstand hurricanes and protect buyers from the devastation that Hurricane Katrina brought to the people of Alabama, Louisiana, and Mississippi.
Hurricane-resistant design
Most structural failures during a hurricane are a result of inadequate design and construction practices. Conventionally, homes have several weak points, such as windows, doors, corners, connections between floors, and connections between the roof and walls, all of which make homes vulnerable to wind damage. Builders need to keep these weak points in mind, applying design and construction methods that enable homes to resist hurricane winds. These general guidelines help ensure a home is built to withstand hurricanes:
Build the home low. The lower the home is, the better, because the wind has less area on which to blow and exert pressure on the home.
Build a hip roof. Hip roofs reduce winds better than gable roofs.
Build a roof with a 5:12 slope. A shallower slope reduces the wind forces against the roof.
Build a wind-resistant roof. If you install shingles, use wind-resistant shingles. If you install tiles, attach them with mortar or foam, and secure them with four to six fasteners per tile. They won't be blown off the roof as easily.
Reduce the sizes of overhangs. Smaller overhangs are harder for wind to lift up.
Don't locate windows near corners. Any opening you put in the corners will weaken the home. Windows built at corners make the home more susceptible to being racked out of shape when the wind blows.
For more information on protecting your homes and homeowners from hurricanes, visit FEMA's website or read our related articles:
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