@Missionaries Well. I agree about the toxicity , but it is already in your car, and basically everywhere if you live in a normal wood house or if you have an air conditioning system. You could spray the urethane and then put another shotcrete layer over the urethane and it will be encapsulated between the 2 walls. If the urethane is not constantly being rubbed upon and aspirated , then I dont think it would affect you. Concrete also have to be covered, and breathing concrete powder is not any better. Just my 2 cents.
@hajjargibran can you use the little dragon to make insulation for quonset hut? and if so do you have any additional info on doing so? I spoke with the airKrete company who insulates and they said their products is different than yours. your aircrete is not a foam type for insulating. They use MgO cement. Do you think I could use that type of cement with the little dragon to make a lighter aircrete??
I also love earthships, I know that in the earth berm, there is suppose to be a thermal break a few feet past the tire wall. I think this would be a great place to put aircrete instead of the double layer of foam insulation. Also, there has been some debate as to weather to build the floor into the earth, or insulate it. The Brighton earthship has had many temperature issues http://thingsthatwindmeup.blogspot.com/2010/06/some-thoughts-on-earthships.html. If you feel your ground is warm enough to regulate the temperature in your home, then no insulation is needed. However, if you feel the earth does not meet your temperature need, then you could put a layer of aircrete under your floor and pour a regular concrete floor over it to use as thermal mass, or just use the AC itself as a floor and use only walls for thermal mass.
Thanks for your comments. You can certainly build 40' d x 20' h domes with our technique. The largest we've built, pictured in our videos is a cluster dome 32' wide x 21' high.
I don't know anyone who has tried using urethane foam for foamed cement. It has enough strength without adding cement.