Center Drain Tub to Glued Sch 40 PVC - Ideas for Best Connection?

[Zane Bridgers]

Hello -

I want to use Sch 40 PVC for my tub drain connection rather than the cheapo corrugated flex tubing they provide from streamline. I finally got the P trap lined up for the drain hole (slab on grade construction) and now need to figure out the most watertight connection from the tub drain assembly to the rigid pvc.

1. The 1st picture is the not yet glued drain layout

2. The 2nd shows gluing everything up and then installing the threaded drain connection through the tub (the challenge would be keeping the lower gasket in place and hoping it can suck up the glued fittings enough for a good seal)

3. The 3rd photo shows having the drain already threaded to the PVC FIPxSlip fitting so both gaskets are good and tight, then gluing up the slip fitting and dropping the tub onto the P trap with wet glue. This final move would be challenging but if tolerances were precise, would offer a good connection at the brass tub drain.

4. Have another idea? (I cannot reach the drain with any tools once the tub is set so a regular slip joint wont work)
The bottom photo shows the tub, where it will be installed, and cheap corrugated tub and fittings that came with it.

Should I put some silicone or putty on those gaskets for redundancy or are they good dry...?

P.S. I ran separate plumbing for the overflow...

Thank you so much for any suggestions!

 

[Master Plumber Mark]

Well good luck with that.... if you get that perfect I would like you to come to work for me...

Just a thought
you might be wiser to make the hole in the concrete a lot larger and set it up with a
1 1/2 x 3 or 4 inch pvc fitting sitting flush with the concrete...

set up the tub with some kind of basket drain with an 1 1/2 tail peice in it that would just drop into the cup drain indirectly.......
This would give you a lot of wiggle room and as long as the drain is flowing good it should
never give you an issue... something like they do in a kitchen with an indirect drain to the floor..

You want to install a cleanout on that overflow if they are both tied together...
as long as the drain is running good it will never be an issue

If it were to stop up some day it would have to be cleaned out through
the basket itself with a small cable machine... so you would want to find a basket
that will allow a small cable to pass down through into that trap

good luck

 

[Sponsor]

 

[Zane Bridgers]

I was out of time to go shop for new plumbing parts so I very carefully mocked everything up a few times, dry fitted the tub with everything glued up except that last slip fitting in 2. and then finally glued it and went for it. It actually went pretty smooth, the tub ended up about 1/4" off the wall because the glued pvc wouldn't flex more than that, so I just bumped out the cement board a bit.

Not saying I would take that approach again, but I guess I'm hired