Tornado force winds place a tremendous strain on a home, especially to the roof. Dangerous pressure is created by severe winds pressing on outer walls and pushing upward against the roof overhang. The combination of these forces can break already weak connections and cause the roof to lift clear of the structure.
Wind forces against a roof are uplift forces, which is why almost every weather.com tornado video features roofs blowing up and off homes.
“The roof lifts off and the walls are left without any lateral stability or bracing. They tend to collapse outwards, and the house looks as if it’s exploding,” said Ernst Kiesling, professor of civil engineering at Texas Tech University, “So if you can keep that roof on, you have more resistance against the wind.”
An inexpensive, but effective way to help protect your home during a tornado, is through ‘hurricane clips’.
Hurricane clips are galvanized-steel clips that connect trusses or rafters to the top plate of the roof. This greatly increases the connection strength, giving greater stability to the entire home. Hurricane clips provide extra security ranging from 400 to 1500 pounds or more of high pressure protection. The type of clip your home needs depends on your tornado risk, and potential ferocity of wind strength.
It is vital that extra precautions are taken to protect the integrity of your home during high wind events. If you are replacing or repairing your roof, be sure to ask your contractor about the addition of hurricane clips to better prepare your home for severe weather.