I am just beginning to do some renos to my basement. I am installing a shower in a bathroom that currently only has just a sink and a toilet. I am trashing the toilet and sink and putting in new ones. This is a concrete basement. How do I connect the shower drain to the toilet drain? Is there a special abs fitting?

J

Hey there: No.. no special fitting required, just a 3x2 wye (or 4x2 wye if 4" pipe). I am going to assume that the existing plumbing is set up in a wet vent manner in that the sink vent also vents the toilet (should be a 2 inch pipe/vent from lavatory for this to be true). Whether that is the case or not..I would connect the new wye fitting behind the fittings that exist for the sink and toilet and go from there (2" waste to shower, including 2" trap, and 1.5" vent required. (I actually run all 2" ...even for vent..underground, then add a dandy cleanout or test tee above floor and then reduce to 1.5" pipe for vent... but that is in Massachusetts.. so... up to you).

So long story short... I would probably repipe all.. so easy cause plastic.. you know. So I would wet vent the toilet (i.e. roll 3x2 wye above centerline and pickup lavatory with that... vent must continue 2" to vent stack for it to be a legal wet vent... also can pipe the shower vent into this), then the other 3x2 wye can pick up the shower (don't have to roll above centerline of pipe... but never a bad thing if you can). And, no... you cannot use a double 3x2 wye because you can not roll the fitting above center line for the wet vent. *smirk*.

Underground plumbing can be challenging... so you may want to consult your local plumbing inspector for requirements/tests in your area. Good luck! If my answer was helpful, please RATE MY ANSWER by clicking on button below!! Thank you