I'm soon to start my latest winter project - finishing a portion of the basement. I pretty fortunate that there is only a small hair crack on the floor, after 16 years. With days on end of rain we have only shown dampness on either side of the crack.
I am not going the route of a subflooring. I intend to first apply a cement stain for some protection. Thought about putting down tar paper or a 6 mil plastic, but thought that maybe overkill. Opinions?
The floor will be partially tiled and the remainder will be carpet. For the carpet, I intend to first put down a 1/2 mat. I'll be gluing all surfaces.
For the tile, not quite sure what to do here. Since I want the carpet and tile to be pretty even, I know I have to compensate for the mat and maybe even some of the carpet pile.
One thought I had was to apply plywood (1/2), then Schluter®-DITRA Membrane (1/8). But this kid is on a budget.
My second thought was some combination of widths of plywood with cement backboard on top.
Open to suggestions.
I have a feeling over the next couple of month, I'll be visiting these forums alot (LOL)
I am no expert on basement floors, but I know a little, as I am an electric guru for Watts Radiant Suntouch (tech support, etc.)
Generally speaking, I rely on others for some specialized information, and when it comes to moisture in basements: Do not use wood!
Wood will soak up the water and rot, will not release it quickly, and the consensus is to not use it. Ditra might be a good base, as it is synthetic, and would allow space for the water to leach to, and there are synthetic products like Ditra specifically designed to create an air space between a damp or wet slab and finished flooring. The specific product names escape me at the moment, but some googling might yield the result you need.
As long as it is just a damp spot, hopefully that is all it will be, and french drains and sump pumps will not be in your future. This kind of thing surfaces from time to time in my business, and can be a real headache if not done correctly.