Well...the downstairs bathroom of this house I bought 18 months ago is very small and outdated and always smelled musty, so, wanting to expand it a few feet anyway, I gutted it with the idea of modernizing it and redoing the tile, etc. Pretty normal stuff. House is on a slab, btw.
Upon taking apart the builtin cabinet thing, I found a hole in the slab [about 1 ft x 1 ft] had been cut for the bathtub plumbing and drain to run through. [Not sure why a hole is needed, maybe that's normal ?] The toilet and sink are on the opposite wall, a distance of 6 feet. The waste stack is right by the toilet of course. So on one wall I have a tub with water supply and 2" drain. On the other wall, a sink and toilet with another water supply for them, and the drain for them is the main stack.
Looking in the hole in the slab I noticed that the drain coming from the tub does not meet up with the pipe it's supposed to connect to. There's a gap of a few inches. This means of course that the tub drains into the ground under the slab. No telling how long that's been going on, but the tail of the pipe coming from the tub drain is heavily rusted.
What are my options ? The only one I see is to [have a plumber] cut a path into the slab from the bathtub over to the stack and connect the bathtub into the main stack. This would surely cost a bit. I could move the tub over to the other wall but of course, unlike the sink, the tub drain is below grade.