The follow-up letter from Mosby and the addition from JWR both list some of the reasons I specifically excluded geodesic domes (twice) in my Dome Homes as Survival Retreats article. They are usually of conventional materials (wood, plywood) in non-conventional (non-square) angles and shapes; thus things like using regular shingles on the roof (more of the structure) which is full of angles is going to be difficult and likely cause problems (leaks). Also, a geodesic dome, which is made up of many flat geometric shapes coming together to approximate a dome, does not really offer the strength of a pure dome, and creates a tremendous number of seams to seal and leak (water and air). JWR’s citation of Bernoulli’s principle was a good addition. Many laymen when considering the effects of high winds upon a conventional structure believe the windward side (side facing into the oncoming wind) is going to collapse inward (like in the 1950s nuclear blast film clips). With hurricanes though, it is in fact usually the leeward side (the far side) which instead gets sucked out by the low pressure created by a vortex of winds coming over the structure where the structure ends. Everyone realizes that round shapes are aerodynamic, thus resistance to wind and creation of low pressure are both minimized with a dome. People also like to mention how concrete homes can withstand high winds. Last year in Stoughton, Wisconsin, around the time of Katrina, a tornado went through and wrecked over 60 homes. There was a concrete poured wall home there, and as I recall, several people enjoyed mentioning to me how it was still standing. The problem was that it’s conventional roof was torn off. The inside of the house was water damaged, so what is the point of having impregnable walls when you roof is going to fail? I don’t think they saved much on the insurance there considering internal water damage requires a lot of replacement with all the mold worries now, but more importantly, in a TEOTWAWKI situation, there isn’t going to be insurance money nor contractors nor supplies to fix it. IMHO you have four above-ground choices as I see it with a concrete house. 1. Get an industrial heavy gauge galvanized steel roof (and listen to the rain). 2. Put span-crete on your roof (and make your walls thick enough to handle the weight). 3. Spend a tremendous amount of money for extra conventional materials and labor to wrap, brace, and tie twice as many trusses as normal deeply into the reinforcing rods of the concrete walls with steel cables (lots of hand work), such as the codes in Dade County (Miami), Florida require 4. Consider a Dome Home.- Rourke http://groups.yahoo.com/group/survivalretreat
Letter from Rourke Re: Dome Homes as Survival Retreats
