Moving Toilet, Adding Shower To Toilet Drain Line - Please Check Diagram

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Hi,

I'm adding a shower to one of the bathrooms on the main level of our house. We have two bathrooms back to back, and both toilets are connected to the 3" copper stack via a double san tee just below the floor. All DWV plumbing is in basement.

I'm planning to cut the toilet horizontal drain and move the toilet to provide room for the shower. The toilet will still be 3ft horizontally from the stack when done.

The shower drain and P trap will be plumbed into the 3" horizontal drain pipe that I'll cut the toilet from via a Fernco coupler. Distance from drain to stack is about 2 ft.

I'll install a 3" ABS wye below the san tee and connect the moved toilet to it via 3" ABS pipe with Fernco couplers , and the distance to the vertical stack will be about 3ft.

All fixtures will be sharing the 3" copper stack that goes to the roof for venting.

I have included two drawings, one before and one after.

Does my plan look correct? Could someone please check my diagrams for proper use of fittings and for proper venting and make recommendations or let me know that all is well?

Thanks very much for your help.

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Existing.jpg
New Shower Add.jpg
 
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hj

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depending on WHICH fitting was used for the two toilets, it might NOT be a good idea to connect the shower to it, and if you did do it the way you indicate, then the new toilet connection would have to be vented. If you connect the shower to the vertical line, it will also have to be vented properly.
 
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depending on WHICH fitting was used for the two toilets, it might NOT be a good idea to connect the shower to it, and if you did do it the way you indicate, then the new toilet connection would have to be vented. If you connect the shower to the vertical line, it will also have to be vented properly.
Thanks so very much for your reply. I sincerely appreciate your help with this.

Regarding the shower, I can extend the 2" pipe from the P trap on the shower to 2 feet and cut the 3" old toilet pipe closer to the 3" vertical stack and then use the Fernco 3" to 2" adapter which would place it much closer to the vertical stack. Would using the 3" vertical stack that close to the P trap and trap arm suffice for a shower vent? If not could I use an AAV vent for the shower midway after the P trap?

Regarding the toilet, if the 3" stack cannot suffice for a vent for the toilet, would it be acceptable to try to run a 2" pipe up the wall into the attic and then 90 degrees over to the 3" stack and tie in with a saddle T for the toilet vent? That scenario would also require adding a 3"x2" wye below the toilet outlet before the 3" toilet drain pipe goes into the 45 fitting that will be connected to the vertical stack. Or in the worst case scenario if I can't get a 2" pipe up the wall into the attic, could I use an AAV device?

This is a small bathroom that I'm working on, and each nook and cranny in the wall has pipes since there are two bathrooms back to back, and the spaces between the joists below all have pipes and HVAC ducts occupying them.

Or should I scrap the entire idea and forget about adding the shower? This 3 bedroom house only has one bathtub and it would be nice to have another shower.

Thanks again, all help and advice is absolutely appreciated.

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Jadnashua

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The existing santee is possibly problematic...when it flushes, it could shoot across the T and into the new shower. If it were a Y, not an issue.

Also, above ground, you must use banded couplings (Fernco makes some), and not an all rubber, non-reinforced one to make the connections. I think you're planning on using the all rubber ones with just a hose clamp at each end...not allowed in your proposed configuration. Considering Fernco makes many lines of different things, calling something a Fernco can be quite misleading.

One additional thing to keep in mind...code requires a minimum of 15" either side of a toilet's centerline with no obstructions...make sure you move the toilet far enough to provide that required space. An older install might not have had it, but the codes need to be followed on a remodel.
 
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The existing santee is possibly problematic...when it flushes, it could shoot across the T and into the new shower. If it were a Y, not an issue.

Also, above ground, you must use banded couplings (Fernco makes some), and not an all rubber, non-reinforced one to make the connections. I think you're planning on using the all rubber ones with just a hose clamp at each end...not allowed in your proposed configuration. Considering Fernco makes many lines of different things, calling something a Fernco can be quite misleading.

One additional thing to keep in mind...code requires a minimum of 15" either side of a toilet's centerline with no obstructions...make sure you move the toilet far enough to provide that required space. An older install might not have had it, but the codes need to be followed on a remodel.
Thank you very sincerely for your helpful reply.

If I cap off the half of the santee where the toilet *was* and put a Y below the santee and run the shower drain to the Y, that should solve the problem shouldn't it?

If so, how about if I use a double Y below that capped off santee and feed the shower to it on one side and then the new toilet drain into the other side?

That would mean that one toilet (existing) would drain above the Y and the new toilet and the shower would drain farther below.

Also, would there be the venting issues to consider or would the 3" stack provide vents for all of these fixtures with the Y configurations described, or would AAV's be needed or actual vent piping?

Regarding the banded couplings, thank you for that very good information. I can see that I'm going to have a problem with that since the 3" stack is copper and I'll be using ABS for the new configuration. The diameters are very different......

We are working real hard to get the 15" clearance on the toilet as near as possible to code. We'll be using a pedestal sink next to the toilet which should help somewhat. The existing vanity to wall spacing was 26" so we're moving the sink over a bit to try to get the few extra inches....

Thanks again for your help, the wife and I both sincerely appreciate it very much.

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Jadnashua

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You can combine them all into the same drain, but you do need to provide vents for each fixture. Well, the top one would be vented by the pipe going up, but anything below it would need a vent line. Code says you should have your vent line go up at least 42" or 6" above the flood plane of the highest device. IOW, you don't need to go all the way to the attic or the roof to connect into the vent, but you do need one to prevent the traps from being siphoned dry by the waste passing by. Once a line becomes a drain, it is always a drain and cannot be used as a vent.
 

Jadnashua

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You can combine them all into the same drain, but you do need to provide vents for each fixture. Well, the top one would be vented by the pipe going up, but anything below it would need a vent line. Code says you should have your vent line go up at least 42" or 6" above the flood plane of the highest device. IOW, you don't need to go all the way to the attic or the roof to connect into the vent, but you do need one to prevent the traps from being siphoned dry by the waste passing by. Once a line becomes a drain, it is always a drain and cannot be used as a vent.
 
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You can combine them all into the same drain, but you do need to provide vents for each fixture. Well, the top one would be vented by the pipe going up, but anything below it would need a vent line. Code says you should have your vent line go up at least 42" or 6" above the flood plane of the highest device. IOW, you don't need to go all the way to the attic or the roof to connect into the vent, but you do need one to prevent the traps from being siphoned dry by the waste passing by. Once a line becomes a drain, it is always a drain and cannot be used as a vent.
Thank you very much. We appreciate your help.

All the best,

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Bluebinky

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edit: I'm not a pro, so listen to the others, like Terry first...

This may be too late, but...

Assuming there are no joists in the way, I would extend the same pipe to the moved toilet. Then tie the shower drain below the toilets, run up next to the new stack and tie the vent in above 42". Worst case you might have to put a slight jog in the new toilet drain.

If joists are in the way, then reconnect both toilets into a double Y and tie in the shower drain+vent below that.
 
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Terry

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glynn_5.jpg


I would get rid of the cross fitting first.
You can put a wye in, and wet vent the shower over the new toilet location.
Or put in two wyes, and vent both and tie in the vents at 42".
You can go six feet on the toilet arm.
They make a shielded Mission coupling that is copper x plastic sizing.
 
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