I got a uncle that lived in the upper peninsula of Michigan. he worked for the county road comish. he built a cabin on a slab no footings nothing. He "got" procured- some limestone gravel and put down about a 10" base and then a plastic sheeting vapor barrier and poured 71/2" of concrete (the width of a 2x8) and built a small house on it. Hear in Michigan your rat walls are suppose to be 48" .This was about 33 years ago but the house still appears to be in good shape, even though he's long gone. how do slabs make it in AK, parking lots and such? I poured cement in my pole barn about 4" and it has cracks and some small shifting of height at the cracks. no big deal its just a barn. just wonerding.