I'm enclosing an integral garage for more living space and had a question about putting pressure treated sleepers down to straighten the wavy concrete floor. I'm pretty sure the was no vapor barrier laid down prior to the floor being poured. Should I put a layer of 6 mil plastic down and then the sleepers? If not, should I put sil sealing foam down underneath the sleepers (so wood does not contact concrete) or Liquid Nail the sleepers or just plain old tapcon them down? I read the other threads concerning the rigid insulation. I'm just concerned with moisture causing mold problems in the future. (Not that I have ever noticed moisture wicking up from the floor in the last 11 years).

Thanks in advance.