I have a 12'x20' basement that I'd like to make more usable. Nothing fancy, but at least have carpet down there. My first obstacle in doing this project is figuring out what to do with the existing concrete floor. Below are some pictures of it, the floor sounds solid in some spots and hollow / not so thick in others. In an attempt to see what is going in the thinner sounding parts I took a hammer and broke some up. Beneath what looked to be a half inch thick piece of concrete I found lightly compacted sand/dirt. Note: the sand felt a little moist, not dripping and not clumping together but it sure was not dry to the touch.

So... With the moisture in mind I'd really like to avoid installing a french drain. I don't think I'm that low on the water table to require that or any level or serious tanking. Ideally I was thinking of some sort of impermeable roll on solution for the floor. Something to "seal" between the carpet and the concrete. Below is also a picture showing two options A and B of what I was thinking.

So the questions that I think I have are.

1. Given that I'm simply trying to make the space usable, nothing fancy... Can I get away with the not so thick concrete floor.
2. Are one of the two options A or B shown below legitimate methods for preparing a basement floor like mine.
3. (This was not disucssed above) If I were interested in leveling the floor a, can anyone point me in the right direction for that need?

Thanks!

 

Bump. Thanks for the advice.

 

That's unusual!

Typ for basements you just have to be sure to use a pad designated for below grade use.

You have a slab issue.

How many spots are there? If basement has always been dry I'd consider just patching.