View Full Version : 11" rough in??? Do I get 10" toilet or is there another option

12-11-2004, 04:56 PM
I just bought a new house and the rough in is 11". The existing 30 y.o. toilet fits perfectly but I have never heard of an 11" rough in. Should I just get a 10" toilet and deal with the space behind it or is there another option? I went to my local plumbing supply and they told me to have a plumber get an offset flange.



12-12-2004, 11:35 AM
You are close on this.

Most 12" rough toilets have 3/4" behind the toilet, thus they will mount with 11.25" from the wall, measured from the wall to the center of the drain.

Sometimes you can move the bolts out that extra 1/4" and install the standard 12" toilet anyway.

If not, the other option is the 10" toilet.

TOTO now has a 10" dual flush at the factory.
I'm bringing some here for the Seattle area (http://www.easycarts.net/ecarts/terrylove/WaterSense_Toilets.html#CST412MF.10).
CST412MF.10 (http://www.easycarts.net/ecarts/terrylove/WaterSense_Toilets.html#CST412MF.10)

http://www.easycarts.net/ecarts/terrylove/images/cst412mf.10 (http://www.easycarts.net/ecarts/terrylove/WaterSense_Toilets.html#CST412MF.10)

12-13-2004, 04:06 AM
Thanks Terry!!!

I have a 12" toilet to replace also so I will buy that one first and try it to see if it works.

04-07-2008, 06:22 PM

Hi all-

I'm definitely not the plumbing type but ran across this thread and am wondering if things have changed in the last few years.

I'm remodeling the downstairs bath... 11" rough in exactly, in concrete. I cannot adjust the screws forward at all. The old toilet was smack right against the wall.

I was coveting the various ECO Toto's based on the reviews here but all seem to be 12" roughs.So I guess 10" is it? Or does the adapter allow me to readily sit a 12" rough on an 11" rough?

I was going to do this myself but may need to go the plumber route to get this right.

Reader Review
04-07-2008, 06:31 PM
The Eco Drake works at 10-7/8"
So 11-0" shouldn't be a problem.

04-07-2008, 06:40 PM
The Drake and Eco-Drake both show in their specs a 1 1/8" gap behind the tank. In theory it should fit an 11" rough in with a 1/8" gap betwen the wall and the tank. However, There are tolerances in the manufacturing process and we are hoping that it would not be a plus sized toilet. You could give it a try and see if you get it in there... Its a shoehorn fit for sure!


04-07-2008, 06:58 PM
Thanks guys!

Redwood- that's a good point. I looked at the specs online

Looks like they are giving 3/4" from the wall? So in theory I'd be 1/4" short, right? If there was no play...

04-07-2008, 07:06 PM
The Eco Drake works at 10-7/8"
So 11-0" shouldn't be a problem.

Really? Hmmm.

04-07-2008, 10:06 PM
We set the Toto Drake at 11" all the time.

04-08-2008, 04:07 AM
Thanks Terry.

And thanks for the service this forum provides.

04-09-2008, 01:36 PM
We had the same problem last summer (2007) with a 11" rough-in.

********* sells a (Glacier Bay) Niagara 1.6 gpf toilet with the 11" rough-in. Note this is the 1.6 gpf version (not 1.3 gpf). We've had no problems flushing larger "objects".

The Niagara toilets are flapperless. I like this, since it seems to me that I'm replacing flappers every two years or so, even w/out the use of cleaning tablets in there. Also, there's no wasted water running down the drain while you wait for the float to fall back down. Out of interest, does anyone else perceive this as a better design to toilets with the flappers?

04-09-2008, 01:36 PM
****** is the big box outlet with the initials H.D.

04-09-2008, 02:01 PM
Niagara toilet with flapperless tray. does anyone else perceive this as a better design to toilets with the flappers?

Not when we have reports of the tray sticking against the side of the tank and running.
Or how often the handles break.

It certainly is an option though. They work from 10" to 12"

04-09-2008, 02:55 PM
Hmm, it still seems like a good design to me. It's the execution that seems flawed.

Or how often the handles break.
That's the manufacturer using a cheap quality part.

Not when we have reports of the tray sticking against the side of the tank and running.
This I have seen when my 4-year old (or myself) gives the handle a half-harded push and only half the water empties out of the tray. A simple fix is to push a little harder and pull up on the handle afterwards. The whole step takes less than a second. I list this one in the same category as slapping the handle on a regular toilet and having the chain kink, which also causes the water to continuously run.

04-09-2008, 03:06 PM
Except there are lots of people with hearing problems, and some with faked hearing problems.
They hear the water running and running, but just walk out.

Some of my older customers can't hear when they have a leaking toilet.
They give me this funny look when I ask them how high their water bill is sometimes.
And when they look at their next water bill, Well then it's imperative that I get right out there and fix their old leaker.

You don't have to jiggle the Toto handle.

04-10-2008, 07:22 PM
I still remember well the first Niagra Flapperless Toilet I ever saw. It was in the home of an HD employee and it was clogged! They were paying me to auger the toilet...

I told him that he should stop buying toilets there because they don't sell the Toto line.:D

I'm less than impressed with the Niagra Flapperless design and have now augered quite a few of them. I do wonder though... When Niagra goes belly up where are the parts going to be?:confused:

04-13-2008, 11:23 PM
Can't an offset closet collar (flange) be used if you are able to remove the old one?

04-14-2008, 10:33 AM
I was considering using an offset flange to move my toilet over a couple of inches - purely cosmetic reasons. However, I found that the offset flanges I could find (and it of course makes sense) are quite a bit deeper than a standard flange, meaning you need to lower the drain in the floor, which then of course impacts your slope to the stack.

Maybe there are offset flanges out there that you can retrofit into an existing system, but it seems to me the very nature of an offset flange would require some additional height.

While I'm typing, I have a silly question. It seems 'rough-in' for toilets actually means from the center of the drain to the drywall, not the framing of the wall. When I read 'rough' I have always assumed it meant to the framing, i.e. the rough carpentry. Thankfully I've not been installing toilets all over the place ;)

So is this really the definition of 'rough-in' - i.e. to the finished wall surface?

04-14-2008, 11:30 AM
Yes, the rough-in on a toilet flange is from its center to the FINSHED wall (note, this does not need to deal with baseboard unless it is huge, but wainscoating can be a problem - it is the new thicker wall!). that may be one reason my most toilets have a planned gap behind them, but it varies...if you install the flange properly, any 12" toilet should fit on a 12" rough-in.

11-16-2010, 11:37 AM
I also have an 11" rough in, and would like to use the Drake. But I notice the current model shows only 13/16" behind the tank (as opposed to the 1 1/8" shown in the drawing above).


Will that still work with 11"? Sounds tight...

If not, is there another 11" option? I'd rather not go to 10" and have that space behind :-(


11-16-2010, 11:41 AM
The Drake II, CST454 needs 11-1/2" for the rough-in
The Drake CST743, CST744 can get by with 10-7/8"

04-09-2011, 11:53 AM

I'm new here and no a plumber. After tiling one bathroom (and in the middle of tiling another, I decided to look into getting a Toto. I want to buy 2 Totos (Aquia II and Guinevere) and know that the RI is ideally supposed to be 12" away from the finished wall. I want to put them in a historical house that has toilets in no particular place and the RI in one toilet measures 11.5 and in the other 13.5. What is done is these cases?

How critical is this 12" dimension?


04-09-2011, 12:03 PM
The Aquia II needs 11.5" on the rough and the Guinevere needs 11.25" on the rough.

On the 13.5" rough, the toilet sets out a bit farther from the wall. With the Guinevere, you could install with the 10" Unift and pull it back 2" closer to the wall.