View Full Version : What size toilet should I shop for 11 - 11.5"? Also flange anchoring question

12-06-2011, 10:04 PM
The distance between my newly tiled wall and the center of the flange is going to be 11 - to 11.5" What size toilet should I shop for?

I also have a flange screw/anchoring question. I screwed up and installed my radiant heat wires a bit too close to my flange for comfort. I will be able to sink at least three of the 6 screws all the way to the subfloor - at least one on each side. The other three, I would like to predrill and sink some plastic anchors into my tile. I could then screw the flange to the plastic anchors. I can go 1/2" for the tile, about 1/8" for grout and another 5/8" for Ditra XL - so a total of just over one inch. do you think this will suffice? Is there a different flange I could use?


12-07-2011, 06:50 AM
You will want to use a 10" toilet. Most 12" toilets are spec'd to work at about 11, but various tolerances MIGHT make one fit 11, and another one of the same model might need 11 3/4". I just think you don't want to play it too cute and find the lid just won't quite sit down!

If you get two screws into the subfloor, frankly that will hold the flange. A couple more screws is gravy. You don't need 6 or 8 screws on a flange.

Gary Swart
12-07-2011, 10:52 AM
Toto makes several model of toilets that use their Unifit adapter. With adapters in 10", 12", and 14" sizes, you can fit these toilets on any of these rough-ins. These models come standard with the 12", the other two are about $50 each. The installation is different than other toilets, but they work very well and enable the toilet to be installed and look right on any of those rough-in sizes. Not only look right, they are all very attractive toilets and perform well as all Toto toilets do. One problem with a regular 10" toilet is there are few choices in style. You can peruse these on this web site by following the links at the top of the page. Just Shop for Toto to see all of the Toto toilets as well as the Unifit models.

12-07-2011, 11:17 AM
The CST744 Toto Drake works at 10-7/8"
The CST454 Drake II works at 11-1/2"

Other brands, if you check their spec sheets will show the space between the tank and the wall when installed on a 12" rough. Just tank the "space" measurement and subtract from the rough measurement.

12-07-2011, 11:36 AM
Thanks on the toilet advice. I will see if the wife wants to spring for a toto. Do any of the big boxes carry Toto?

Regarding the flange, I was thinking that two screws would be fine. I am going to get a live wire detector as well and see if I can sneak in a couple more screws. I have already repaired the heat wire once - clipped it with a trowel, so I would rather not go that route again.

12-07-2011, 05:41 PM
If the heat mat is that close, then the extra holes needed for a Toto Unifit aren't likely a great idea. The Drake mounts just like any conventional toilet...i.e., only to the flange and wouldn't be an issue. Toto chooses not to sell through big box stores as they tend to demand price points and concessions they are unwilling to make. But, many local plumbing supply and showrooms do carry them, so there's a good chance you may find one locally, and usually at much less than the suggested retail on their website. I like to see at least 4-screws on a flange, one either side of each toilet bolt location. You can get by with fewer.

12-07-2011, 05:52 PM
IF the heat cables are that close to the toilet, they may melt the wax ring under the toilet.

Gary Swart
12-07-2011, 06:10 PM
If melting the wax ring is a possibility, you can use a wax-less ring such as the Fluidmaster. These work just fine. Toto toilets are not sold in discount stores. If there no stores carry Toto toilets, they can order one for you. They are also available on-line, but use care if you order on-line as damage in shipping is often a problem. Inspect everything carefully before accepting delivery. Toto is not the cheapest toilet on the market, there are plenty of cheap builder grade toilets available in the discount stores, and if you don't mind plunging frequently and really want to go cheap, they would be an option. Toto Drakes will compete with AS price wise and out perform them in use. Remember, a toilet is usually a once in 30 to 40 year purchase, so spending a little more and getting a superior product might be worth considering.

12-07-2011, 08:35 PM

In the last few months I replaced two toilets at my home with Eco Drakes. One with a 10" rough and one with a 12" rough model.

Instead of Wax rings I used http://sanisealgasket.com (http://sanisealgasket.com/) I was very impressed with the Gaskets and ease of installation. They are reusable and they are not affected with floor heating elements.

Here are the measurments i just took.

12” Rough-In model, Toto Drake Elongated 2 Piece Toilet CST744EL#01 Cotton White:

Flange is 11 ” from finished wall. Space behind tank is 3/8”. It therefore requires at least 10 7/8” space from flange to finished wall as Terry stated above.


10” Rough-In model, Toto Eco Drake Close Coupled Toilet CST744EF.10#01 Cotton White:

Flange is 10 3/4" from finished wall. Space behind tank is 1 ”. It therefore requires at least 9.5” space from flange to finished wall.

Hope this helps.


12-07-2011, 09:55 PM
This will almost certainly melt a wax ring... so definitely use an alternative. My hydronic heating system has to be held back a minimum of a foot from the flange, they prefer 2 feet. Electric runs at lower temperature than hydronic, but at that distance, you will no doubt melt your wax.

12-08-2011, 07:29 PM
Thanks for the help, advice, experience and understanding. I knew I was too close to the toilet when I took the picture - would have taken me 10 minutes to move prior to my slc pour. Oh well - live an learn. Gonna use a waxless ring and try and convince the wife we need to upgrade the throne.

12-09-2011, 01:07 PM
Licensed plumber just told me to install it flush?! I know you guys told me to install it on TOP of the tile.

What gives?

12-09-2011, 01:49 PM
With a waxless seal, having the flange flush to the floor will not be a problem.

12-09-2011, 04:58 PM
A plumber wants to be in and out, not do the rough-in then wait maybe weeks to come back to install the flange after the finished floor is on. They are designed to be installed on top of the finished floor. A waxless seal uses a funnel to direct the waste into the drain and doesn not use the top surface of the flange (with wax) to create the seal; it uses a different means, depending on the brand, to seal to the inside of the pipe, not the top of the flange. That's another reason shower liners sometimes end up being installed flat on the floor...he wants to get the drain installed and a flood test done, not wait for the tiler to build the preslope so the drain and liner can be installed.

12-09-2011, 08:02 PM
Gonna use a waxless ring and try and convince the wife we need to upgrade the throne.

I found that if you use the SaniSeal Waxless Ring a single SaniSeal can be used even if the TOP of the Flange is 3/8" BELOW the finished floor. If it is more than 3/8" you can stack two of them. Stacking them does not cause deformation as it would with 2 WAX rings.

Check out this YouTube video http://www.youtube.com/watch?v=c3xuNYnnlfM