@anthonydjones The size and depth on your foundation are going to be determined by where you live, and how large of a structure you are building. Generally, if you live in an area that is a cooler climate, that freezes regularly. Your foundation will need to be below the frost level in your area. 30-36 inches down from surface level will keep your foundation from shifting during the freeze and thaw cycles. A typical "footing" for a foundation is 12 inches by 12 inches. This is actually over kill for an air create dome, but will insure that it has a reliable foundation. Hope this helped.
Posts made by Junior
RE: how many bags of 94lb cement needed approx. to build a 20ft. dia dome?