OK, the backstory can be found in this previous questions: Repairing leaking DWV vertical 3" thin wall PVC. Basically, found mold growth behind baseboards of a powder bathroom adjoining the kitchen. Discovered it was due to a slow condensation leak from the joint of a vertical radon vent pipe in the wall. With help from Stack Exchange, I figured out the pipe size, cut out the leaky joint, made the repair with two slip couplers, and everything was great. The area stayed dry for a good (dry) month.
However, we recently had a sizeable snowstorm, and when I checked the pipe today, the new joints were great, but there was water on the base studs next to the pipe. Looking closer, there is water coming up from the slab where the vent pipe exits the slab. From my pictures previous to the repair, I see there was some sort of sealant around the pipe at the base, which looked old and worn so I removed it.
I'm particularly concerned about a source of water underneath our foundation, as awhile ago I discovered in our kitchen a few tiles that cracked (all in a semi-straight line, covering the kitchen, and pointing towards this powder bathroom). I haven't pulled these tiles yet, but I can see the foundation under the kitchen island, and there is a smallish crack (<0.125") in line with the cracks in these tiles.
- Should I seal around the radon vent pipe at the slab foundation, to prevent the water seeping up? If so, what should I use?
- Should I be worried about water underneath our foundation?
- If I should investigate further before sealing the pipe base, what should I look for? Or who would you call to investigate a source of water under the slab foundation, a plumber?
One last thing, that may be important, the hot water to the kitchen sink has always been slow (about half flow speed of cold; faucet has a continual lever). Previous owner said it was a safety feature of the faucet, but I've never had a plumber check it out.