We were just talking about strawbale roundhouses the other day. (See: Straw Bale Roundhouses Built in One Day.) This one is in New Mexico. I highly encourage people to try gravel bag foundations. (Polypropylene bags or tubes filled with gravel.) They could have saved a great deal of time, money and effort. A small, simple foundation like this one can be built in one day with two workers. Our free websites and articles explain the details.
– Double bag gravel bag foundations (one bag inside the other) for added strength.
– Fill bags with scoria/lava rock if you want insulated foundations.
– Use baling twine or poly or nylon strapping to stabilize bags of lightweight fill material (prevent shifting) and to secure the first course of bales to the bags.
– Use 18”x30” poly bags. They will align perfectly with most straw bales.