Plumbing: adding onto a horizontal toilet drain

[fordperson]

Hi everyone,

Currently I am redoing a small shower which had a bathtub and toilet. The tub was the standard 1 1/2 drain and now I would like to convert it to a full 2" if possible.

Running a new 2" pipe all the way to the vertical stack is quite impractical so I am looking on advice on running the 2" drain into the existing 3" toilet pipe.

Here is the mock up picture for reference. I would wye the 3" using a 3-3-2 and use the 2" leg for the shower drain. From my understanding the 2" pipe needs to be vented separately so I would use the previous 1 1/2 vent for that purpose.

PS Location is naperville,il


Hope I made it clear, thanks a ton again.
Tom

 

[fordperson]

Just to add to this a bit, is the 2" drain required by code? I found this in the pluming code, but I am not sure if it indicates the whole run needs to be 2" or just the drain flange.

---
Section 890.690 Shower Receptors and Compartments
a) Shower Installation. All shower compartments, except those built directly on a
slab floor or having receptors constructed of precast stone, terrazzo, concrete,
molded stone, molded fiberglass, or an equally durable material such as cultured
stone or synthetic stone, shall have a lead, copper, ABS, PVC or fiberglass
shower pan. (See Section 890.230 entitled Safe Pans.) All sides of the shower
pan shall turn up at least 2 inches above the finished shower floor level. Precast
molded receptors shall have a minimum ¼ inch thick flange. Traps shall be
constructed so that the pan is fastened to the trap at the seepage entrance, making
a water-tight joint between the pan and the trap. Shower receptacle waste outlets
shall be at least 2 inches in diameter and have a removable strainer.
----

Tom

 

[Sponsor]

 

[hj]

WHERE is the "Y". They probably would NOT allow that low inlet 1/4bend for the toilet, for several reasons. But, if they did the shower WOULD need its own "proper" vent.