How To Engineer Your Next Home to be Tornado-Proof

Tornadoes produce the most destructive forces a house can experience. Around four times as great as a big earthquake or hurricane.

Damage from the 1964 Alaska earthquake.
Alaska Earthquake 1964

Tornado-proof houses have been constructed in typhoon alley in the Marianas Islands for 50 years — since 1963. They have stood up without structural damage to sustained winds of over 240 mph — equivalent to an EF5 tornado. They have survived a number of earthquakes, one equivalent to the Mexico City event — without structural damage. In order to resist the tremendous forces from a big tornado, both walls and roofs must be engineered reinforced concrete, structurally designed and connected together to act as a single box-shell. They can be easily insulated for energy conservation.

These houses are engineered and constructed according to the "box-rigid-frame" concept, developed in Japan to accommodate the forces imposed on housing units by a significant earthquake. Structurally, a box-rigid-frame house performs like an aircraft fuselage which experiences huge wind speeds.

San Bruno fire of 2010.
San Bruno Fire 2010

As a result of designing with box-rigid-frame techniques for big tornado winds, the house is also earthquake-proof and hurricane-proof. By nature of the concrete construction materials used throughout, they are fireproof. (Note to Texas and southern California.)

Wood frame walls and roofs, as currently designed and built in North America, cannot survive high intensity wind-related disasters. This has historically been amply demonstrated, and particularly so with the recent tornadoes in the southeast USA. A search of the Internet will not likely show the intact survival of a single wood-framed house after a direct hit by an EF4 or EF5 tornado, or even a category 5 hurricane. Recent explosives tests by the government on box-rigid-frame construction also show superior disaster resistance. Concrete box-rigid-frame walls are essentially bullet-proof.

Every house designed according to box-rigid-frame methods must be analyzed by and utilize the design services of a licensed structural engineer. This is the best and lowest cost insurance policy against future failure and only needs to be done once — at the time of construction. Such houses cannot be designed by prescriptive specifications.

Hurricane Andrew in Florida.
Hurricane Andrew 1992

Now that the state of the art of box-rigid-frame technology for single family houses has been proven over 40 years, there is no excuse for building homes that will self-destruct and kill or injure those who live in them.

Guidance and Planning Advice for Disaster-proof Homes

For more information, email info@tornadoproofhouses.com.

Where Do I Go for Help?

For local information about this kind of construction, contact your local ready-mixed concrete supplier/s. Not all of them will have the details you seek, but many can tell you where to look for help. For building material information, go to the Internet and search on "ICF house construction." There are a number of excellent insulating concrete wall form producers. Most of them provide thorough technical service during design and are usually willing to provide helpful guidance during construction. Reinforced concrete roof systems are essential for tornado security. Insulating concrete roof forms are available from most but not all ICF manufacturers.

Who We Are

CPM Associates