I am planning on putting in an aircrete sub floor because I think it would be at least 1/2 the cost of blue foam. I'm a believer in insulating floors, cold feet, no good. Then I want to put about 2 inches of earthen floor on that. It is a large room 20 ft. x 40 ft. and will be a sort of sun room 2 sliding doors and 6 windows so when the sun hits in the floor it should store a lot of heat. I'm doing 10 ft. squares at a time.
I think this is a fairly economical way to build a floor, carpet may be cheap but they also off gas things as well as the plastic underneath that you do not want in your body. Even though Portland cement may not be the best for our environment, I think is a lot better than Styrofoam.
Here is a video I made of my aircrete foam generator. It's a new toy so I'll be make a lot of things with it I hope.
Thanks for watching and God bless.