I bought a 1980 condo last year and had to move in quickly, so I wasn't able to remodel beforehand. I finished laying some nice bamboo upstairs about 6 months ago and it is holding up very well. Now that it's warm again I've been wanting to finish downstairs. After ripping up the existing carpet(no mold underneath), I've noticed that the slab underneath weeps a lot, but only where I have something sitting on it, like underneath plastic buckets, or a litter pan. It only take a couple of hours and there will be moisture there. I have purchased 2 calcium chloride tests, but it's painfully obvious that I don't need to use them.

I would like to lay my glue down bamboo downstairs as well, and some tile, however I know both will be ruined in short time. Does anyone know how to go about rectifying the moisture problem? Since I am in a condo, I won't be able to do external drainage systems. I had thought I could paint over it with redguard or something, but I've read that will not help considering the moisture is coming from below the floor. I'd like to DIY this, but who would I call if I decided to have it done professionally? Just looking for a cost effective way to keep the water out.