Hi,
I'm redoing my roughed-in plumbing and was wondering if I need a separate vent for my shower, or the sink vent will be sufficient to vent the toilet and the shower (wet venting)? Also, does this layout look OK with the fittings? Is there a rule how far can the wye connection be from the back water valve? I apologize if I'm asking too many questions. Thank you very much.

Yes you will need a regular dry vent for the shower AND the WC drain needs to be downstream of the lav drain. Just wye off to catch the WC and then wye off to catch the lav. WOW on the drawing..really impressive.



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yeah, the shower needs a seperate vent and you want a cleanout in the 2 inch lav drain. the shower vent will need to be 2 inch for the portion of it that is below grade. once above grade it can be run 1 1/2 inch
i don't see anything wrong the way the toilet is wet vented thru the lav.
roll up the 'Y's a little if you can, especially the shower vent..

There is absolutely NO REASON why the toilet has to be "downstream" from the lavatory. IF that were true it would compromise at least half of the bathroom designs AND plumbing layouts.Techicallly, the cleanout is supposed to be the same size as the "main drain', i.e., 3".

There should be a cleanout tee above the back to back fixture fitting for the double lavatory.
Depending on the distance you might be able to run the shower drain behind the toilet and tie it into the lavatory drain. That would prevent you from have to pulling another vent for the shower.

Our inspectors would want it BELOW the B2B fitting, and since it is a "main line" cleanout it would be 3" with a bushing on top for the B2B fitting above it. The shower would have to go into the riser, so there is probably not enough elevation below the floor for that and since the shower is already at the max distance from the toilet, the lav is even further away so it would not work anyway.



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Thank you all for your comments I really appreciate it. NC plumber that is how the shower pipe is routed right now, but I wanted to see if I can do something better. I have two choices the one that is shown on the first post or this one. I believe that I have to add 2 cleanouts (one where the shower vent is and another one @b2b fitting) with this configuration since the shower pipe is too long.



I'm already digging the concrete so I wanted to get some more ideas. This is how it looks so far. The red dots show the existing shower drain line and the blue dots the existing WC drain line. The green lines and the red circles show where I'm planning to put the new pipes. This option is best for me because I don't have to do lot more digging.



Thank you for your help.



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You are either making this too complicated, or getting caught up in trying to use a bunch of fittings. ONCE you have the shower vent where you show it, you CAN connect the shower to the 3" and make a shorter run without the turns.

my code says if a fixture can be removed to give access for snaking then that covers the requirement. so no 3 inch cleanout needed as the toilet can be removed. the lav drain will need a 2 inch cleanout tee in the vertical section.

Normally, I would prefer a root canal to removing a toilet to snake a line, but in this case,
1. It is on an elbow into a straight run
2. It would probably never be used, and ,
3. The backwater valve can be used for the cleanout, and should be otherwise the snake will get stuck in it.

hj, do you mean something like this?

Yes. I was trying to figure out what that yellow pipe was until I saw it was a sledge hammer. Its head looked like a T in the line.

i am totally unfamiliar with 'la marteau de forgeron " or as it is affectionalely know in montreal.. la grande masse

I finally got down to the existing pipe, so hopefully this will be my last change of the layout. Will I still need to vent the shower if it's connected like this? I read that the max distance for the went for 2" pipe is 8 ft. If the 2" pipe doesn't work then I can put 3" pipes for the sink toilet and shower. The reason I want to get rid of the shower vent is because I won't have where to put it with this layout (I read that I can't run horizontal dry vents). Again thanks for the help and happy Easter.

you will need to vent the shower. you can vent up thru the wall between the shower and the toilet.
remember, code says minimum size below grade is 2 inch. so you need to use a 2 inch "Y" and street 45 looking up into the shower side wall. once above grade reduce to 1 1/2 inch. seems silly but that is the code.

OK, so I guess I need to do it as I was thinking in the beginning (it will have extra fitting and long pipes but it will work, hopefully ). Does everyone (or most )agree with this layout? thanks for your patience and understanding





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If you're going to pull a vent on the shower trap, you can use a heel inlet 90 under the toilet and tie it in there. Less concrete to remove. There's no need to run it around the toilet and into the sink drain.
You could also use a 3" X 2" wye just downstream of the toilet 90.

NC Plumber that's a good idea for the heel. What's the downside of running the shower drain around the toilet and into the sink drain? That pipe it's already there so I just wanted to tie into it. If I tie the shower drain into the toilet then the shower vent will need to be 6" higher than the toilet flood level in order to do horizontal run right? I'm putting shower seat against the wall so I was thinking to route the vent thru there into the wall or just put AAV on top of the vent below the seat with access panel.



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The shower vent will need to be 6" higher than the lavatory flood level before it turns horizontal.
Here in NC we can go 7' from the trap to vent, most states are 6', judging by the pictures you might get by without a vent on the shower if you are within that distance.

The only thing I would add is, for the Drain line, use long turn sweeps, where you can, it will facilitate using a larger in diameter snake. The idea of using the space under the sink is a good one but I would install a regular vent and forget about the access panel. Access panels are a good thing where you need access at a future date though.