Can you make your home withstand a tornado?

house with torn shingles from a storm
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Seeing the tragic consequences of the December tornado outbreak in the Midwest, I’m sure many folks are wondering if there are ways to make homes more resistant to wind damage, whether it’s straight-line winds or tornadoes. The answer is yes.

How winds interact with buildings

Homes affected by strong winds may be overturned, slide off its foundation, or completely lifted off of the foundation. Winds will be slowed or sped up when coming into contact with buildings, depending on the direction of wind and angles of the roof. Air approaching a vertical wall directly will apply pushing pressure to that wall, while the wall on the opposite side will experience a suction or pulling pressure. Roofs will also undergo pushing and pulling pressures. Side walls to a wind always have a pulling or suction force as the air speeds up to catch up with the air going over the roof.

Since winds can come from any direction, these pushing and pulling forces will be different depending on its direction of approach. Internal pressures on walls and roof will also be occurring at the same time.

The larger the opening, the greater these forces will be. A good example is a garage, especially since most garage doors don’t do a good job of stopping air infiltration. A strong wind hitting the garage door is almost like blowing up a balloon. If the wind is hitting the side, it will cause air to be sucked out of the garage. In many cases, garages are the first and most damaged part of the house when significant wind damage occurs.

Wind-resistant Construction

While it is cost-prohibitive to make a home or other buildings completely resistant to wind damage, wind-resistant construction can make a home or building able to withstand stronger winds with much less damage and potential life-threatening conditions. In some cases, this may require the expertise of a structural engineer, especially for larger buildings. However, there are resources available for contractors and others to learn more about wind-resistant construction.

The Windstorm Mitigation Manual for Light Frame Construction authored by Dr. David Wickersheimer provides information on the basics of wind loads on buildings, nailing, and framing. In addition, information is provided to mitigate structural damage from moderate to high winds. The manual can be downloaded as a PDF from the Illinois Digital Environment for Access to Learning and Scholarship.

 

MEET THE AUTHOR
Duane Friend is an energy and environmental stewardship educator with University of Illinois Extension, serving the organization in many roles since 1993. Duane provides information and educational programs to adult and youth audiences in the areas of soil quality, weather and climate, energy conservation, and disaster preparedness. These programs provide practical solutions for families, farms, and communities.  He assists families in creating a household emergency plan, farmers with the implementation of soil management and conservation practices, and local government officials and business owners with energy conservation techniques.

ABOUT THE BLOG
All About Weather is a blog that explores the environment, climate, and weather topics for Illinois. Get in-depth information about things your weather app doesn't cover from summer droughts to shifting weather patterns.