[mmcporter]

Actually budnate, you are correct. We put several mil polly on the ground between the crushed stone/sand and the slab. We also put fiberboard around the perimeter of the foundation before pouring the slab so that expansion and contraction can happen in a controlled way. We also took the masonry saw and cut some lines into the slab so that there is less likely to be cracking later. Finally, we used 3,500 PSI cement and put a ton of rebar along the front end where the garage meets the driveway so that the beginning of the slab won't crack if a car sits there.

Fun stuff!!