I know this is not a natural material but I can't help but think how cheaply you could build a super insulated building by filling icf concrete forms with aircrete. Not sure of the strength level if you buried it in the ground or if it would be strong enough for a foundation or starter wall for a cob building. I certainly wouldn't want to go to the trouble to build a cob building just to have the foundation fail. I think it would be great for a wofati or a greenhouse because you would probably have a R-80 or more insulation and then put a cob wall against that on the inside for thermal mass.
They say aircrete has the strength of a conventional 2x4 wall at 16 inches, but that would depend on the mix and there is a lot of room there but you may be able to add additives such as paper fibers and such or maybe a fortifier.
I always try to find ICF's on craiglist left over for cheap. You end up with different manufactures and they do not fit together but can be reinforced with plywood and 2x lumber and they can work out great, maybe a little dab of Great Stuff here and there.
I know its not natural building material but it may keep the leftovers from ending up in the landfill. Also here in Missouri the state has made everyone remove all the Styrofoam floats so there is a lot of that laying around, I think a guy could cut that up into blocks, build a house and put chicken wire and stucco over it. Would be very cheap and fast but not sure about it gassing off toxic fumes.
I would love to hear anybodies input, even if to say I'm crazy, if I am I want to be the first to know.
Always! Wait. Never. Shut up. Look at this tiny ad.