Here is my dilemma. Customer bought a house back in December. Has one bath that needs to be remodeled badly. Plan is to get a second bath up and running before tearing apart the existing bath. House was built in 1968, so all cast iron drain piping. At the time of construction, a basement bathroom had the drain piping roughed in. Basically a 4 inch toilet rough in at floor level, a tapped TY for the sink, and a 2" pipe sticking out roughly where a shower or tub drain would go. Its in a less that ideal spot so it had to be moved. Floor is flat smooth concrete. I busted open the floor and smashed a line open to roughly where I needed the shower drain to go. The underside of the concrete had a plastic vapor barrier, and the bottom of the concrete was very smooth. Felt like porcelain, it was so smooth. As I was digging down the foot or so to the shower drain P trap, I hit water. I was digging down through 1" round stone. Turns out there is a sump pump in the far corner of the basement, and when I looked the water level in the pit was the same as the water level where I busted up the floor. Part of the basement is finished and looks like its been finished for several years, so I assume no ground water issues in the past. No cracks anywhere in the concrete floor, no disclosure at the selling of water issues. Between the pump, the gravel, the plastic barrier, and whatever they used for concrete, the water level has managed to stay at bay. Now that the floor is compromised, whats the best way to put this back together to keep a water tight floor? What do I use to seal around my shower floor drain so water does not come up? I plan on doing a tile custom shower floor and walls. Home owner wanted vinyl plank flooring, but I am going to insist on tile now that I know whats going on. My main concern is that this isn't the wet season here. In a few weeks we get the spring rains and ground water levels rise. A big storm can knock out the pump. Is there an epoxy type waterproof slurry I can pour around the shower drain and under the toilet flange once I lead that into the 4" cast? Is basic hydraulic cement my best option on the cement floor I have to fix now?
