# Floor mount/wall discharge WC ques.



## leakfree (Apr 3, 2011)

6 story bldg.in Illinois,4" waste stack,4' vent stack,2 side by side baths (only WC and lavs,tubs/shw and kit are on a different stack) per floor on each stack.Job was originally figured with floor dis. WC,now they want to change 2 thru 6 to floor mount rear dis. WC.I've never done a new install with these WC,wall mount carrier WC are always 4" waste piping,any old floor mount/ wall dis. WC I've removed were 4" waste piping.The problem is limited space in the wall and they won't fatten the wall,does it say anywhere that the waste above the floor for the WC can't be 3",Illinois code doesn't specifically address this and 2 local inspectors that I asked didn't have an answer,does it address this in the UPC or IPC codes?


----------



## Redwood (Sep 8, 2008)

Floor mount rear discharge toilets do not use a wall carrier instead the use a closet flange, so yes there could be a 3" line plumbed to it.

Now all you have to do is find out about your code.


----------



## U666A (Dec 11, 2010)

Red is correct yet again. A floor mounted/rear outlet w/c does not require a carrier as the load is being supported on the floor. You simply rough in the w/c flange at the height according to the shop drawing and away you go in 3". But make sure you use a rubber gasket, not a wax one.

Now if the g/c has spec'd carriers for some bizarre reason, you might be in some trouble due to the "no reduction in size" code. Has anyone ever seen a 3" carrier? I certainly have not.

Sent from my iPhone using PlumbingZone


----------



## leakfree (Apr 3, 2011)

No carriers are spec'd,the job was originally floor discharge.The Illinois code doesn't really address this situation.There is a 4" waste stack at the end of one bath and a 4" went stack in the other.The plan is to hang a horizontal waste below the floor w/a combo on it's back at each WC and then up thru the floor to a vert. tee, out to the collar and the WC,pick up one lav on the waste below the floor and get the second lav off the stack above the floor,all ind. vented(no wet went's or crosses allowed),just not sure if 3" will fly.Two local inspectors were of no help with the ques.,might have to call a state guy.


----------



## U666A (Dec 11, 2010)

leakfree said:


> No carriers are spec'd,the job was originally floor discharge.The Illinois code doesn't really address this situation.There is a 4" waste stack at the end of one bath and a 4" went stack in the other.The plan is to hang a horizontal waste below the floor w/a combo on it's back at each WC and then up thru the floor to a vert. tee, out to the collar and the WC,pick up one lav on the waste below the floor and get the second lav off the stack above the floor,all ind. vented(no wet went's or crosses allowed),just not sure if 3" will fly.Two local inspectors were of no help with the ques.,might have to call a state guy.


Sounds fool proof to me. In my jurisdiction you can drain 27 F.U.'s to a 3" horizontal branch. The only exception to that is as soon as you tie in a 3rd w/c to a horiz branch, you must immediately increase to 4".

Sent from my iPhone using PlumbingZone


----------



## U666A (Dec 11, 2010)

And why are wet vents not allowed? You can save alot of money doing it when it's practical. And what do you mean by "out to the collar"? I have never heard this terminology before. Why is it you think 3" might not be big enough? Maybe the picture I've painted in my head is configured wrong, but it dents seem like you're loading too much on a branch...

BTW, did you post an intro already?

Sent from my iPhone using PlumbingZone


----------



## Airgap (Dec 18, 2008)

leakfree said:


> 6 story bldg.in Illinois,4" waste stack,4' vent stack,2 side by side baths (only WC and lavs,tubs/shw and kit are on a different stack) per floor on each stack.Job was originally figured with floor dis. WC,now they want to change 2 thru 6 to floor mount rear dis. WC.I've never done a new install with these WC,wall mount carrier WC are always 4" waste piping,any old floor mount/ wall dis. WC I've removed were 4" waste piping.The problem is limited space in the wall and they won't fatten the wall,does it say anywhere that the waste above the floor for the WC can't be 3",Illinois code doesn't specifically address this and 2 local inspectors that I asked didn't have an answer,does it address this in the UPC or IPC codes?


 
*Hello! Introduction Requested* 
An intro is requested from all new members. In case you missed it, here is the link. http://www.plumbingzone.com/f3/.

The PZ is for Plumbing Professionals ( those engaged in the plumbing profession)

Post an intro and tell our members where you are from, yrs in the trade, and your area(s) of expertise in the plumbing field.

This info helps members who are waiting to welcome you to the best plumbing site there is.

We look forward to your valuable input.

:thumbsup:


----------



## leakfree (Apr 3, 2011)

U.A.til.I.die said:


> And why are wet vents not allowed? You can save alot of money doing it when it's practical. And what do you mean by "out to the collar"? I have never heard this terminology before. Why is it you think 3" might not be big enough? Maybe the picture I've painted in my head is configured wrong, but it dents seem like you're loading too much on a branch...
> 
> BTW, did you post an intro already?
> 
> Sent from my iPhone using PlumbingZone


In Illinois we use the State of Illinois plumbing code but local villages are allowed to have amendments to it,the village where this bldg. is located has an amendment that does not allow wet wents,fixtures back to back on crosses,all hangers and supports are to be of a manufactured type(no copper tacked to copper braces)bla bla bla.By"out to the collar"I'm refering to coming thru the floor with a vert. waste line in the wall,installing a tee on the vert. with the branch going hor.to the closet collar at the wall face and venting the WC off the top of the tee to a hor. vent bar and over to the vent stack.


----------



## U666A (Dec 11, 2010)

Airgap said:


> Hello! Introduction Requested
> An intro is requested from all new members. In case you missed it, here is the link. http://www.plumbingzone.com/f3/.
> 
> The PZ is for Plumbing Professionals ( those engaged in the plumbing profession)
> ...


You're going to have to be quicker on the draw than that AG, I beat you to it! :laughing:

Sent from my iPhone using PlumbingZone


----------



## U666A (Dec 11, 2010)

leakfree said:


> In Illinois we use the State of Illinois plumbing code but local villages are allowed to have amendments to it,the village where this bldg. is located has an amendment that does not allow wet wents,fixtures back to back on crosses,all hangers and supports are to be of a manufactured type(no copper tacked to copper braces)bla bla bla.By"out to the collar"I'm refering to coming thru the floor with a vert. waste line in the wall,installing a tee on the vert. with the branch going hor.to the closet collar at the wall face and venting the WC off the top of the tee to a hor. vent bar and over to the vent stack.


Understood

Sent from my iPhone using PlumbingZone


----------

