When building a sub-floor, should I put the vapor barrier under the sleepers? Should I put insulation in it? Will there any drainage problem?
Answer:
I would never install a sub-floor in a basement unless it was absolutely necessary. Now, yes there will be a drainage problem no matter where the VB goes and no, I would not put in a VB. The only insulation I would use is white (cheap) beadboard between the sleepers and that would be for sound insulation. You are not going have much success insulating for heat retention. Money would be better spent on installing peel & stick tiles right on the concrete and putting in scatter mats or area rugs where you need them.
