I got wind of this site from TSPpodcast, which I thought was great. I was hoping to get some help getting information on specifically what to do with expansive clay in re-guard to the foundation phase. I have been studying up on building an eco dome , but with all the reading and the videos they only mention that building on expansive clay is different and they dont go into what to do about it. I have not been able to google anything that has really detailed information on what to do to prep the site before building the structure. I understand what expansive clay does to normal construction over time, but I'm not so sure as to how it will effect the eco dome. I live in s. central texas, I have done my field tests to find out what percent cement I will need ( 20%)and I'm just about ready to order some bags and get started but I need to fully understand the foundation phase before I get started ya know. I hope someone can help me out!
Well I got word back from the Cal-Earth people, and this is what they suggested..
How do local builders address this. Some places in California require > that the ground under the foundation be completely saturated to achieve > full expansion. Then sustain the water in the ground through irrigation. > > My suggestion is to find the condition which is the easier to sustain. If > the ground is usually wet then build when the ground is wet. Remember to > keep it wet during drought. If dry, then keep the ground surrounding and > under dry with french drains, steep grading, paving the surface with > bricks, plastic sheeting with ground cover, and or stabilized earth. > > The impact of expanding or heaving soil on these buildings will be less > damaging than to rectangular building, therefore, look to local successes. > > To maintain the longevity of the barbed wire in the foundation wrap the > bottom layer with plastic in order to damp proof it and then damp proof > the exterior with more plastic or below grade waterproofing. > > Frank Lloyd Wright had used an idea call a floating footing with some > success look at this link: > > http://cobstudio.blogspot.com/2006/06/rubble-trench-footing_12.html
Now that I have better information I can finish my final design and maybe get the darn thing built this year!