Venting Wall-hung WCs. Unusual Question.

[geniescience]

Have installed two Geberit carriers (110.816, not Tessera) for two Euro-Style bowls, back to back.

Instead of drilling two holes in my concrete slab and connecting the two toilets straight down to the branch separately, I drilled one hole only. Am planning to connect the two closet drains into one pipe.

1. Which connector do I use ?? Two options, shown below. Either using Wye's or San-T's and 1/8th bends.
2. And venting. Can I vent them as shown below?

David

[hj]

"Legally" you can't do them either way. The opening has to go directly into the "vent" without turning down first. I am not sure what kind of carriers you were given, but most carriers are a combination of the toilet holder and the drain pipe in one piece.

[geniescience]

Good remark. And I do believe you. And, I think the Code has not yet thought of this unusual situation.


If I had placed these two rear-discharge toilets at a 90 degree angle to each other, their discharges could have gone straight into a secondary stack with dry venting above them. Now these two discharges can't go straight out, they have to turn down, to avoid hitting each other. AND... I still want the venting !

I'm not a plumber. This is my first major DIY project. Your comment helps me understand that I do have a little dilemma here.

Can someone tell me that either one will work, but that this or that problem could occur if implemented as shown ?

[hj]

How are the toilets arranged? Offset sideways from each other or back to back? Being that they are toilets, funcionally they would work, but you would never get an inspector to approve either setup.

[dubldare]

Not sure if you're doing a true back to back setup.

If you are, and your waste is dead center, you're looking at adding another hole.

[geniescience]

These two Geberit carriers have to be connected to a new drain. The hole has to be drilled.

[Winslow]

If I were doing that I would make two floor penetrations, 1 directly below one of the toilet outlets (vent underground as a standard toilet) the second off to the side (vent with a heel outlet 1/4 bend above slab). The drains on them carriers can drain either straight down or to the side. the drains connect under ground, but the toilet that is vented underground would have to be at the end of the line. Either that or come through the floor separatly then tie in the two vents 24" above finished floor (tie in has to be 6 inches above the height of the bowls off the floor. Doing it the second way requires having a bigger plumbing wall as the drain pipes will sit side by side.

http://www.terrylove.com/forums/attachment.php?attachmentid=6020&stc=1&d=1230323207

[FloridaOrange]

Maybe I'm missing something, which would be good because I like to be educated, but why are you using two separate carriers? There are several different beack to back setups that work well (J.R. Smith). I would have done it with a single stack to a single carrier with a single vent.

[Winslow]

the gerberit has the tank in the wall. Using JR Smith would require using a flush valve, which requirea a 1 inch water service to feed 2 toilets, for 1 thing.

[FloridaOrange]

That would be what I was missing. Thanks :) .

[hj]

Not necessarily. The JR Smith carriers can be used with any wall mount toilet; tank type, flush valve or tank in the wall. There is nothing between or above the top bolts to prevent the use of your tank.

[Winslow]

you need the carrier to hold the tank, it comes as a unit.