Bathtub waste tee mystery

[danowar]

hiya folks. a while ago the tub in my house started draining into the bathroom floor, and a bit of investigation revealed a collapsed pipe segment going from the drain shoe to the waste tee. i live in texas, the land of slab foundations and no basements, so access to those components is tricky (at least without demolishing half of the bathroom). i finally got back in there and found that, after removing the hardware attaching the drain pipes to the tee, the tee itself was... surprisingly easy to remove. after extracting those components, i'm left with kind of a puzzler. in the attached diagram, it looks like there should be a tailpiece going from the drain fitting to the outflow pipe in the foundation -- there doesn't appear to actually be one here, though. as near as i can tell, it looks like the drain fitting was literally just sitting on top of the outflow pipe. it wasn't threaded into anything, nor did there appear to be anything going up into it. in looking at the pipe coming out of the foundation, i can't see how it would have positively attached to anything. i've attached several pictures, one of which is the drain fitting simply placed back where it had been, as it was prior to removal (though with the other pipe segments going from it to the tub removed, because the access area is pretty tight). am i going crazy here?

could the tailpiece have fallen out of the drain fitting and into the outflow pipe, and that's what that bit of pipe coming out of the foundation actually is? if so -- what do you _do_ about that?

(house was built in the early 70s, and i suspect that none of these components have been touched since initial installation)

thanks very much for y'alls time. cheers!

 

[Reach4]

could the tailpiece have fallen out of the drain fitting and into the outflow pipe, and that's what that bit of pipe coming out of the foundation actually is? if so -- what do you _do_ about that?

What is the OD of that piece? If 1.5, it could be tailpiece. If smaller, it could be the piston/lift bucket from another kind of drain.

 

[Sponsor]

 

[Grahampoo]

The casting tee outlet sometimes has both external threads (for a slip joint connection) and internal fine threads. Based on your photos, specifically the one with the waste shoe tube being partially gone from corrosion, I would suspect that yours had an internal threaded tailpiece attached to it and it corroded. That's what you are probably seeing in the floor still.

 

[hj]

If you look at your "fourth" photo, you can see what appears to be the remains of the tailpiece inside the drain riser, (it is NOT an "overflow" pipe).