ist thing is not to panic. Just keep drying it out and see if the buckling settles down. If its prefinished it pretty easy to get some boards replaced. If its site finished you'll most likely have to resand the entire area. It can sometimes take several weeks for all the moisture to leave. I don't think the mold issue is of big concern. The main thing is to let area dry out and see what hsppens.

Floating a floor over a concrete slab is very common. The things to be aware of: flatness...but this is required no matter how you install a rigid floor. Flatness doesn't matter under carpet (which is why builders LOVE to use carpet over concrete)...which is why it can take $$$$ to get a slab (that used to have carpet) ready for a rigid floor. The next thing you need to be prepared for: the cost to get the slab ready for a rigid floor (floating or otherwise). A 'nice slab' can have a price tag of $2/sf. A nasty slab can have a price of $4/sf for preparation costs (includes labout and materials). Once your slab is ready, you can lay your floor. The next thing to be aware of: underpad. Laminates and engineered hardwoods do very will with an underpad/underlayment (like cork). Vinyl does NOT like underpad. So it depends on what type of floating floor you have. And the next thing to be aware of: moisture barrier. This is required no matter how you install your floor. Floating, glue down or the questionable practice of laying plywood first and then nailing a floor to it...you will ALWAYS need a vapour barrier over concrete that is at or below 'grade' (the ground). These are all 'basic' flooring stuff. They aren't directed to a floating floor. They are required for all floors. A floating floor can have a few limits on length of run...but it depends on WHAT it is you are floating and the manufacturer's limitations. Without knowing the type of product you are installing, it is impossible to tell you what to 'look out for'.

I know of no way to run the drain to an existing stack except under the concrete which means the concrete must be sawn (use a walk-behind wet saw with a diamond blade to cut through concrete and steel reinforcement), broken up, removed and replaced once the job is done. This is a project best left to the pros. Even if another way existed, I doubt you could get code approval. Supply pipes, however, can usually be run through the walls.

Thanks...I try. Too many people *think* a concrete floor is a money SAVING project. It is not. A SLAB floor is money saving. It is ugly, unfinished and can be very rough on the feet. A properly finished concrete floor is beautiful but very expensive. Most people think slab concrete is the FINISHED floor and therefore cheap. What they do NOT appreciate is how UGLY it is and how much it stains and etches and degrades over time (chalky dust on the surface all the time). They are very disappointed in a SLAB floor. When they are told the cost to fix a concrete slab floor they look at the refinisher like they have 2 heads and say, "Well if it's going to cost me $10/sf why don't I get hardwood and be done with it?"