I have slab envy. I made mine 12' x 24' and caught heat over it. I also plan on putting up a building over it for wood storage somewhere down the road. I had not put on the last form board in this photo or placed the rebar. Notice the stone wall I built on the right. Some of those stones at the very bottom were 2'x3'x3'. Concrete is now done. OWB is supposed to be in next week.