A thin shell concrete dome home can withstand winds of 400 mph according to Dr. Arnold Wilson retired professor of civil engineering at Brigham Young University. This wind velocity is greater than that produced by a F-5 tornado. Domes have survived without damage in the path of an F-4 tornado that demolished traditional square wood frame homes.
Domes Provide Organic Tornado Damage Resistance
The dome shape is by nature aerodynamically resistant to wind damage or lifting from its foundation in a tornado. It also provides substantial protection from tornado driven debris. At Monolithic Dome Institute (MDI), Gary Clark test-fired a 30-06 rifle into the side of a Monolithic Dome and the high-powered rifle slug did not penetrate the structure. A 30-06 slug travels at 2800 fps or 1,900 mph and exceeds the velocity of tornado driven debris. If the concrete dome shell will withstand a bullet, it will withstand wind driven hard objects as well. According to the Fujita scale of measuring tornadoes, an F-5 tornado will have winds of 261-318 mph.
According to a report to the Monolithic Dome Institute; on April 27, 2011, an F3 tornado, with winds between 158-206 mph, hit the town of Durant, Mississippi, including the dome home and garage of Mr. and Mrs. Lee Avery. The winds blew over 100 year old Beech and Hickory trees that were not able to withstand the winds, but the home was undamaged.
In Birmingham, Alabama, an F-4 tornado passed over the Faith Chapel Christian Center’s seven large domes with winds between 165 and 200 mph on April 28, 2011. The damage to the domes was just cosmetic, but “Made scrap metal from one of their large metal buildings and seriously damaged several other non-dome structures.”
David Holmes of Light Weight Concrete Domes explains that the insulated concrete dome home is, “Designed to withstand natural disasters.” The evidence points out that these domes are accomplishing what they are designed to do.
Dome Strength Protects Against Tornado Driven Debris
What about larger tornado driven items? To test the structural strength of a dome, the Brigham Young University engineering department placed a fork lift on top of a small thin shell concrete dome. The dome sustained the weight without any damage. At the Monolithic Dome Institute, researchers put an airform weighing 8,622 pounds for a load of 400 per square inch. The dome was undamaged. David South, President of MDI estimates that a car propelled by a tornado “Would not have enough mass or tornado-produced energy to be a serious factor when and if it landed on a Monolithic Dome.”
Primarily the only parts of a dome likely to be damaged from a tornado are the windows and doors. Storm window-coverings affixed to the outside of the glass could reduce the likelihood that any damage will occur. Metal security doors are available of sufficient strength that they are marketed to provide high-wind protection.
Sound Deadening Properties Shield Occupants from Outside Noise
One dome resident was unaware of a forty-mile an hour windstorm going on outside until he looked out the window and saw the debris. The dome insulated the occupants from the noise and damage from the storm. It makes sense to construct a family’s primary residence with a structure likely to withstand the winds and lifting force of tornadoes in hazard areas, than to rebuild structures more susceptible to deconstruction during such catastrophic events.
Dome Home Comparable in Cost to Traditional Structure
The cost of constructing a thin shell concrete dome home using modern available methods is comparable to the cost of traditional buildings. But the dome is more sustainable.
When the energy costs of two similar sized structures are considered, the cost of a concrete dome is much less over time. When the life span and maintenance costs of a concrete dome are compared to a wood frame home, the cost of the dome goes down further. When one calculates the exceptional protection from natural and human engineered disasters provided, a dome home becomes inexpensive in comparison.
Change in Thinking Could Save Lives and Reduce Damage
The damage left in the wake of the tornadoes in Oklahoma, Kansas, Arkansas, and Missouri, and the earthquakes in Arkansas, Indonesia, Japan during 2011 demonstrates that it may be time to change how people think about building a home. It could substantially reduce the loss of life and the cost of damage. A tornado will likely wipe any traditional wood frame home off the surface leaving only a foundation and debris behind.
Domes For The World, a non-profit group that provides the training, tools, and methods for constructing superior shelters for the world's most needy. replaced village homes destroyed by an earthquake in 2006 in Ngelepen, Indonesia with thin shell concrete dome homes. The domes withstood the shaking of subsequent earthquakes and continue to provide safe homes in the village.
The United States Federal Emergency Management Agency (FEMA) is helping to fund the construction of thin shell concrete domes as tornado shelters for the residents in two mobile home parks in Licking County, Ohio. Recognizing the effective protection of the dome shape, FEMA reported that the dome shape does not provide an overhang for a tornado to "Get its teeth into" and remove the roof, in its news release dated May 21, 2011, from Clinton, Missouri.
David South, President of Monolithic Dome Institute wrote, “A few more tornados and everyone will want a dome. The reality is we follow the leader. So far in America the leader loves old house designs. We may yet see the world go round.”
Jon Thompson - Jon Thompson - freelance article and commercial writer with background in education, business, advertising, sales and emergency ...
Join the Conversation