Hi all, I'm going to be working on finishing part of my basement to include installing a bathroom. I am wondering since the floor is concrete do I need to install some sort of sub-floor (example: bathroom tile or vinyl-and other room carpet) or will all materials work on the concrete? Thanks for any advise I might get.

Steve

Any material should work over the concrete.

If your tiling, the thinset will get adhered to the concrete. If your floating a floor, there is a manufacture vapor barrier that gets install first. If your carpeting, the pad will go down first, but ask the carpet people if you should install a vapor barrier (plastic or 15 roofing felt). If your installing vinyl flooring, that can get adhered to the concrete. Of course, the surface must be cleaned and dried.

This is all depending how humid and how much moisture is in the concrete. Tape a piece of clear plastic to the floor and seal all sides with the tape. In a day or 2, see if there is any condensation on the slab side of the plastic. If so, a sub floor may need to be installed or vapor barriers installed between the flooring material and the concrete.