I'm in the process of finishing my 1952 basement. The floor previously had tile, likely asbestos (9x9, and there are some tiles peeking out from under the furnace - according to inspectopedia, it looks like asbestos). The tiles were removed by previous owner, and now the slab is covered by the black cut-back (or is it mastic?), which I'll just assume also has asbestos. The slab doesn't show any signs of cracks, and I assume that after 60+ years it's probably done settling. I don't see any signs of water intrusion, including in a separate area of the basement where carpet was laid directly on the slab. The surface is fairly even, but the cut-back causes it to be a bit bumpy.

I'm putting in a bathroom, which I hope to tile, and a storage/laundry area, which I was hoping to carpet.

My question is: what should I do to the slab to prepare for both surfaces? Should I seal with something like RedGard, or perhaps use Ditra? Or can I just lay the tile and carpet pad directly on the cutback? Would tile directly on cutback cause issues?

Thanks!

This post was edited by robhan on Wed, Aug 6, 14 at 18:38