Dual back-to-back tank-in-wall wall hung toilets in 6" wall

[DOD]

Hello all,
I have a mid-70's slab house with two small bathrooms separated by a 6" stud wall. I'm in Texas, and during Hurricane Harvey my home morphed into a U-Boat. I was looking at bathroom fixtures, and liked the residential wall-hung toilets because of the clean lines and the huge space savings from the tank being located in the wall. I liked the Toto line, but could easily be convinced otherwise.

My problem is getting 2 tanks into the wall. Unless I'm missing the idea, no product seems to directly address this.

Any good U-Boat needs 2 ballast tanks, right?.....

Thank you!
Dave

 

[FullySprinklered]

The wall-hung guts take up the space in a 2x4 wall completely. Back to back, you'll need to fir out one side to get two units inside the wall, back to back.

 

[Sponsor]

 

[DOD]

Thanks very much for your suggestion. I could fir out one wall by 2" to make room for the tanks, as you said. However, I wouldn't know how to plumb the pair of separate 4" waste lines with the tanks and toilets being so close together. Is there a special fixture that would handle this situation, and also route the vent so it wasn't bumping into the two tanks?

Thank you!
Dave

 

[Terry]

The vent goes to the side of the tank. These have a 3" drain, and many fittings are available depending on what your existing plumbing looks like. Is this on a concrete slab, over a crawlspace, or on a second story?

 

[WJcandee]

We have a number of wall-hungs in our beach house. To my mind, the Toto Aquia wall-hung bowl is the best. Performs most "normally", cleans the bowl well, looks good. The Toto tank system is flexible and works well.

 

[DOD]

The bathrooms are on the ground floor of a concrete-slab home. I've pulled the two toilets, but have not jacked any concrete. There's a 3" vent line coming out the concrete a few inches to the side of where the two waste lines intersect, so I suspect that a double 90 bend was used as the connection. There is no 2nd floor continuation of the waste line, it services only the ground floor (i.e. there's no stack upwards).
Thank you!
Dave

 

[Terry]

Toilets back to back without the proper fitting will push water out of the opposing bowl during a flush.
Newer toilets flush much quicker and need better ways of plumbing them in to prevent the water in the bowl from disappearing.

 

[DOD]

Terry,
Sorry, I included the picture of the double 90 bend because I think that's what's under the concrete now. It's got to come out, along with the short runs up to both toilet flanges.
If I pack 2 Toto in-wall tanks into the same 8" wall space, then there's going to be a pair 3" waste lines coming down vertically side-by-side. To mate up with the existing 4"waste line, I need a fitting that might look something like this:
Thanks!
Dave
P.S. Thanks for the great installation video of the Toto unit. Very helpful!!!

 

[SH2]

I know this is an old thread but I have the exact same issue but over a crawl space. Is there a purpose made fitting available for this situation?

 

[nodoze]

I could not find any good guidance on my needs and searching brought me to this really good thread (& a couple of other good ones on this forum) so I am sharing what I found in my research in case it helps others. Another thread had a really neat double back-to-back system "all in one" carrier from England but I could not find a way to order here in the US.

I have similar situation and doing 2 in wall back to back to a single drain above my slab/foundation which looks to be accomplished by Geberit via:

https://catalog.geberit-global.com/en-XD/product/PRO_101639

or

https://catalog.geberit-global.com/en-XD/product/PRO_101637


The Gerberit system is available at least via both Amazon & Home Depot (those 2 above parts are not at Home Depot but I found them elsewhere). The downside of the Geberit system is you have to buy 2 separate assemblies and have a wide enough wall. From page 22 of this document you need 8-5/8" for 2x4 carriers and you need 11" for 2x6 carriers:

https://www.geberitnorthamerica.com/_assets/local-media/brochures/gna7189.pdf