Where does the P-trap go?

[blackm3sedan]

It may seem like a simple question, but how do I put a p-trap in here without making it into an s-trap?


It's a room addition which required a new slab and footing to be poured. I think the rough-in drain line should have been installed in the wall cavity and not in front of it. In this picture, the sink is on the left, which will have the vent, with the toilet in the middle and the problem bathtub drain on the right.


Any suggestions?

[jimbo]

You will need to do some digging. You need a tee on the white vertical pipe. The min. distance from the trap to the vertical pipe is about one pipe diameter, so as long as you can fit the tee in and connect the trap waste arm to it, you will meet minimum length almost just by definition.

[mtcummins]

so there's no vent on the tub? is this why you're concerned about an S-trap, that you'll be cutting the rough in line down to the trap level with no vent on it? I'm not sure you can do that w/o creating an S-trap. If you can't connect that vent line over into the other vent, you may have to put in an AAV or something, but I'm not sure... hopefully jimbo or someone else with more experience than me will chime back in.

In looking at it a second time... is there a trap buried in the rough-in? I didn't see that at first... if so, then i think you just need to offset the pvc drain line with a couple 45s and drop the tub drain straight into a 1 1/2" trap adapter, but again, maybe a plumber can verify that this is a legal setup...

[dlarrivee]

You're going to have to pull the tub back out and you might even need to chip some of the concrete away to allow yourself room enough to put a T in that pvc.

[mtcummins]

Can someone explain to me why we're putting a Tee into the vertical PVC? Or a P-trap at all? Am I seeing the picture wrong, or is that PVC drain not vented and there's already a trap below grade?

If its possible to extend that PVC up and tie it into the vent, its probably a good idea, if not code required (someone else can chime in on that, I never do shared vents... don't know the code for them). Then you'd need a Tee to tie in the drain and get a vent.

[dlarrivee]

He asked how to connect a p-trap without creating an s-trap...

[cacher_chick]

Can someone explain to me why we're putting a Tee into the vertical PVC? Or a P-trap at all? Am I seeing the picture wrong, or is that PVC drain not vented and there's already a trap below grade?

If its possible to extend that PVC up and tie it into the vent, its probably a good idea, if not code required (someone else can chime in on that, I never do shared vents... don't know the code for them). Then you'd need a Tee to tie in the drain and get a vent.

We cannot see if there is a trap on the bottom of that riser. If there is, then the installer failed to install a proper vent for the tub.

If there is not, then a sanitary tee will need to be cut into the vertical pipe so that the trap can be installed and the vent can continue upwards.