# How to anchor toilet flange to porcelain tile?



## Bob Mariani

The tile is cut around the flange. This flange should be screwed securely to the sub floor. Best to do it right? If you insist on a cheap work around and accept poor quality work.... you can drill the holes with a masonry bit with a hammer drill set on hammer/drill. Seems to me this toilet will now rock and roll since the height of the flange is too high.


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## tpolk

i thought the flange sat on finished floor height not flush to ff


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## bobmg

*Toilet flange*

The toilet flange is supposed to sit on top of the finished floor. The toilet rests on the rim that runs around the base, but the area above the flange allows for about 3/4" clearance. The flange is only 7/16" thick, so that leaves about 5/16" for the wax ring. The toilet horn projects down level to the floor, so it will be surrounded by the wax ring.

The only question is whether the flange will stay put without being screwed into place.


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## Bob Mariani

maybe some do it this way, but never saw it done. I always make it flush with the finished floor. and tile is cut around it not placed under it. If so his plumber would not be having any issue since he would have to adjust the flange with every tile job? and he would have to always screw into the tile and not the issue he presented which he never had to do this....


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## Bob Mariani

from another site on this subject:

How high above the floor level is tolerable? There is some space under the bowl. however it varies from manufacture to manufacture.



> Should the flange be flush with the tile floor? in a ideal installation, yes. However, it's not absolutely necessary.





> How much lower is the cast iron flange then the tile floor? If you will look on the under side of the bowl you will see a 3" horn. This horn extends down past the flange and directs the discharge past it. Also they make a wax seal with a built in funnel that does the same thing. Why jack your toilet up so it becomes a rocking chair if you can set the toilet on the tile floor, connect it to cast iron flange and have it steady?
> If you still insist on retaining the oatey flange extender you could shim up bowl and set it that way. Your choice.


 Answer #2 from same site


> After I find out that there are no other style of flange or toilet, then I draw a circle around the flange, remove the twist and set, chip out all the tile and thinset so the twist and set will sit near level with the floor.



so from what I see here and in many hundreds of jobs.... seems you may get away with it, but it is normally and should be perfectly level with finished floor, not above it/ Now many times we do not know what finished floor will be, this is why you see shimming adjustment rings used. And if too low you will find wax seals with a tapered plastic funnel bottom to make up the difference. 
So on top.. it might work it might not. And your plumber is 100% right in not taking responsibility for this installation. The tile can crack and you now blame him for your installation issue. Not fair


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## tpolk

i would drill holes thru tile to fasten straight into subfloor. If we knew before we would shim the flange the approx height of the floor to be installed. many of the plumbers i have worked with who were good at what they do would ask for ff height


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## oh'mike

I've been a bathroom remodeler for 17 years---Bob is right flange screwed to subfloor --tile cut around the flange,

You can probably make a success of screwing the flange to the tile--sure won't give you much room for the wax ring however. Do not use glue or silicone to attach the flange to the tile-Screw,that's the ticket.--Mike--


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## Alan

I would be careful doing that... just for the fact that if your screw pushes back out a bunch of thinset chunks and backerboard pieces up against the bottom of the tile it could pop off.

Not to mention, it should be watertight to the finished floor. If you drill holes through the tile and drive screws down, where do you think any leaks are going to go to?


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## nap

why did the tiler install the tile close to the down pipe anyway. If he has done a couple bathrooms, he should know to cut the tile around the flange.

Unless you had directed him to cut it around the down pipe, I would be calling him up to reset the tiles involved so they are cut around the flange.


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## bobmg

*Toilet flange again*

I searched the web beforehand and found the question of flange height posted dozens of times in various forums. It also is covered in a bunch of DIY how-tos. The concensus is for the flange to sit on the finished floor, although there is a sizable minority that says it should be flush with the finished floor.

This is a house I recently purchased. The toilet flange was flush with the old vinyl floor. When I ripped out the old vinyl flooring and the 1/4" underlayment, I found that water had been leaking out between the underlayment and the subfloor. I had a square yard of mold growing between them and about four square feet of rotten subfloor to replace. 

Personally, I would never ever put a flange flush with the finished floor. Just think about it - the horn of the toilet only projects as far down as the top of the finished floor. If the flange sits on top of the finished floor, the horn will project into the flange. If the flange is flush with the finished floor, the horn does not stick into the flange, and you are relying soley on the wax ring to prevent leaks, which does not seem like a good idea to me. I think there is plenty of room under the toilet for a flange and a wax ring.

The tiler has been tiling for 12 years and says he has always seen the flange on top of the tile when he does new construction.

Back to my original question, my choices are to drill holes through the tile and take the risk that the tile may crack or fail at a later time, or just use a silicon caulk and take the risk that the toilet will move around and crack the PVC at a later time. Any more thoughts?


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## oh'mike

BOBMG--You have heard from three professionals that the flange must be securely screwed to the subfloor
-----However---If you wait long enough---someone will tell you to glue it down some way--

That's what you want to hear,right? so wait a bit --surely someone will tell you what you want to hear.


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## bobmg

No, I'm not waiting for a particular answer. I've got two people telling me to drill through the tile and one telling me it's a bad idea, so I don't know what to do.


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## jlhaslip

remove the offending tiles, screw the flange to the subfloor, replace the tiles to just outside the flange, re-install toilet after grouting, and use a wax ring with the plastic drip thingie.


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## Bob Mariani

bobmg said:


> No, I'm not waiting for a particular answer. I've got two people telling me to drill through the tile and one telling me it's a bad idea, so I don't know what to do.



the flange is flush with the finished floor. This is what is correct. please give me the links to those that insist on telling others the wrong way to do it. And as mentioned in these posts.... doing it on the finished surface may work if your are lucky. But it may not work. With the correct installation (screwed to the subfloor) it will ALWAYS WORK! This is why this method is correct!


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## nap

bob mariani. take a look at this. It does show the flange on top of the overfloor so it is actually not flush:

http://www.thisoldhouse.com/toh/how-to/overview/0,,250406,00.html

http://www.thisoldhouse.com/toh/how-to/step/0,,250406_184647,00.html

as well as this one:

http://www.finehomebuilding.com/PDF/Free/021121078.pdf

and this Q and A site for plumbing says to mount the flange on top of the tile as well.

http://www.plbg.com/forum/read.php?1,427470


to drill floor tiles, I would not use a hammer drill. I would use a drill bit like this:










I do use water to keep it cooled and not run it fast..


Before mounting this thing, I would turn the bowl upside down and using a straight edge across the botton, measure how much clearance there is where the flange and the was ring go to be sure you have adequate space for the flange and will have some wax left to actually seal the toilet to the flange.


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## Bob Mariani

all sites have many opinions and many if not most have incorrect answers. What my opinion supports is that in 90% of the cases it is done this way. To the floor.

what is better about it? 
... will work all the time not only with certain toilets
... you do not need to remove the flange to redo the tile
... you have a flat secure surface to attach the flange
... you will not be taking the chance of cracking a tile already in place

The other way.... not one advantage


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## COLDIRON

Why not just use PVC Glue to glue the flange to the floor pipe and leave it level with the floor once that's done you can install your toilet without cutting anything. JUST KIDDING.

Set the flange in place draw a line around it and use a ceramic high speed bit to remove the tile around the flange then screw the flange to the floor like the others have already stated.


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## AllanJ

Does the toilet fit over the flange and touch the floor all the way around its footprint without having to force it down?

If so then you don't have to redo the flange to be flush with the floor.

Now you do need to drill a few holes through the tile so the flange can be secured to the floor.


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## COLDIRON

Sounds like drilling through the tile is a NO NO.


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## RegeSullivan

Toilet flange installation calls for logical thinking. So... 

1. The flange "should NOT set above the finished floor". Why = the toilet may not set properly or seal properly and may crack from the stress.

2. Flange can, but should not set on top of tile. Why = Tile may crack when screwing flange to sub floor, tile will be difficult to replace in the future, however, the toilet will set properly and seal properly.

3. Flange sets on sub floor. Why = Floor can be tiled and re-tiled if necessary, finished floor can be up to 1 1/2" thick and still get a good seal with the proper wax ring.

Since there is no advantage to having the flange on top of the finished floor why would you do that??? So # 2 works but LOGICALLY #3 is the way to do it.

Rege


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## Alan

SULTINI said:


> Why not just use PVC Glue to glue the flange to the floor pipe and leave it level with the floor once that's done you can install your toilet without cutting anything. JUST KIDDING.
> 
> Set the flange in place draw a line around it and use a ceramic high speed bit to remove the tile around the flange then screw the flange to the floor like the others have already stated.


I was just about to type this out after I was done reading. 

Agreed. :thumbup:

IF YOU INSIST on having the flange sitting flush or on top of floor level, then make a spacer to sit underneath it before you mount the flange.


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## bobmg

Just wrapping up this thread in case a DIYer finds it in a search.

When I installed the flange, I put a lot of silicon caulk under it so water on the floor could not run back under the flange and under the floor.

I drilled through the porcelain tile with a diamond drill bit, not the spear bit pictured above. A diamond drill is essentially a tiny hole saw that grinds through the tile and presents less risk of cracking the tile. I used the lowest RPM possible and kept it wet; the bit never got hot, but it took about 40 minutes per hole. I fastened the toilet flange with stainless steel screws and made sure the threads did not touch the tile.

After installing the flange bolts, I caulked all the holes in the flange with silicon and caulked around the outside edge of the flange. I test-fit the toilet and marked its position with blue painters tape. I put a bead of caulk under where the front half of the toilet would sit (forward of the flange bolts).

I put a 3/4" wax ring on the flange and set the toilet on top of it, then slowly pushed the toilet down (and sat on it) to compress the ring until the toilet was solid. By my calculation, the wax ring was squished from 3/4" to 3/8". I caulked around the front half of the toilet only (if it ever leaks, I want to see the water). I let the toilet sit for three days before hooking up the water and using it, to give the caulk time to set up.

That was several weeks ago. The toilet is still rock solid, does not leak, and there is no sewer smell.

Regarding the toilet flange placement:

In this 22-year-old house, the toilet had previously been installed with the flange flush to the floor. Water had seeped out and rotted part of the subfloor. The flooring was removed, the rotten subfloor was replaced, a new vinyl floor was installed, and the toilet was reinstalled. It leaked again over time and rotted out the subfloor again. Repeat: the toilet was installed twice by professionals using a flange flush to the floor, and both times it leaked. The seepage was concealed between the subfloor and the underlayment and went unnoticed until substantial damage had been done. My neighbor had the same problem with his house of the same age.

When I redid the bathroom, I decided that I wanted to avoid another leak at all costs. I deliberately cut out the old toilet flange and replaced it and the PVC so that the new flange could sit on top of the finished floor. There is one BIG advantage to putting the flange on top of the floor. IT WON'T LEAK!!! The horn of the toilet (the toilet's own built-in flange) projects downward into the PVC flange by at least 1/4". In order for this setup to leak, the water would have to run uphill for at least 1/4" up the side of the flange, and then make it through the wax ring. And even if it did manage this feat, the water would be on top of the finished floor, where I would see it and would know to take action.

When you install the flange flush to the floor, the water runs out of the toilet and down the sides of the wax ring before entering the flange. If there is the tiniest gap anywhere between the wax ring and the flange, the water will seep into it by means of capillary action and it will end up between your subfloor and underlayment where you can't see it. It takes years for it to rot out the subfloor, and you won't know it until the damage is severe.

All authoritative web sites I found (like those quoted by nap above) recommend putting the flange on top of the floor. Here are a few more:
http://www.johnbridge.com/vbulletin/showthread.php?t=25754
http://www.johnbridge.com/vbulletin/showthread.php?t=7250
http://www.terrylove.com/forums/showthread.php?17971-Toilet-Flange-Height
http://www.terrylove.com/forums/archive/index.php/t-3630.html
http://www.terrylove.com/forums/archive/index.php/t-22332.html
http://www.askmehelpdesk.com/plumbing/proper-height-toilet-flange-348076.html
http://www.askmehelpdesk.com/plumbing/toilet-flange-height-364948.html
http://www.bobvila.com/wwwboard/messages/258382.html
http://advice.thisoldhouse.com/showthread.php?t=32
http://www.doityourself.com/stry/bathinstallatoilet
http://www.ehow.com/how_5664787_install-toilet-flange-tiled-floor.html
http://www.youtube.com/watch?v=2jl3P7sjxCk
http://wiki.answers.com/Q/What_is_t..._used_between_a_stool_and_flange_on_the_floor
http://www.plumbingstore.com/toilet-flanges.html (scroll to the bottom)

I also checked four plumbing books - all showed the flange on top of the floor in their photos. I contacted the maker of the flange, Sioux Chief, and they said it was perfectly OK to put the flange on top of the finished floor and that most modern toilets were designed for it. I checked the installation instructions for Kohler toilets (www.us.kohler.com/onlinecatalog/pdf/1117173_2.pdf) and their diagram shows the flange on top of the finished floor.

Summary:
Authoritative web sites - on top of the finished floor
Plumbing books - on top of the finished floor
Toilet manufacturer - on top of the finished floor
Flange manufacturer - on top of the finished floor
Personal experience - flush with the floor leaks 2 out of 2 times
Logical analysis - on top of the finished floor can't leak
Risk analysis - if flange is on top of the floor, I'll see leaks right away; but if flush with the floor, not until years later

I can't say that flanges should be always be installed on top of the finished floor; maybe there are situations where the flange is best installed flush with the floor. I'm not a plumber. But I can say this: anyone who thinks that it's always wrong, shoddy workmanship, etc. to put the flange on top of the finished floor, or thinks there is no advantage to it, is mistaken and really ought to think it through again before giving advice.


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## Alan

Just FYI, we installed a toilet the other day that was set on a flange installed ON TOP of the finished floor. It did not work properly. We had to put wedges all around the toilet to get it up high enough so that there was still wax between the porcelain and the flange. Otherwise all the wax would have squished out and the base of the toilet would have been floating 1/4" in the air. 

It does not ALWAYS work.:whistling2:

Also in regards to the wax ring leaking, if the toilet is set properly and the bowl CANNOT MOVE, the wax ring will stay intact for thousands of years. (exaggeration I know). When there is movement for the bowl, the wax ring works itself loose over time and it leaks. You will have the same situation whether the flange is on top of the subfloor or on top of the finished floor. Worse on top of finished floor IMO because you are not secured to the material directly BELOW your flange, but through that material and two others before you get a solid bite into the subfloor.

I'm not saying its wrong, but I definitely wouldn't do it that way, nor have I encountered any scenarios where it would be better that way. Good luck to you.


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## Skoorb

bobmg said:


> I searched the web beforehand and found the question of flange height posted dozens of times in various forums.


I know this post is almost two years old, but me, too. I found pictures of some flush with finished and some over top. This is the first thread I've seen where most seem to say have it sit flush. Just yesterday reading at Lowes in a Black & Decker book on plumbing it showed a flange beautifully placed above a white tile floor  But later in another picture it was flush.

That said, I am tiling a bathroom now and the new toilet I bought from Lowes (Jacuzzi Maxima) *will not fit with the flange over top of finished floor*. I was about to do it like that and with the toilet upside down I confirmed that my flange, if it's on top of finished tile will not let my toilet seat properly--and that's before even any wax is there. So having it on top of finished tile would be completely wrong. I'm using an inside-3" flange (since I failed when pouring the concrete drains to leave space to put an around-3" and I have no interest in chipping away--, but the toilet outlet is smaller than the inside-3" anyway so no loss) but I don't think it is much or at all higher than a regular flange. In my case, I could fit the toilet if the flange protrudes a bit above finish-flush, but resting on top it just won't fit unless I have the entire toilet lifted at all edges.

I redid a bathroom in my house last year and the flange was flush with the plywood subfloor! So, it sat below finished floor, and the previous guy had (successfully) simply used a jumbo wax ring. There are flange extenders, though.

Again, old thread, but the pipe I ran is totally surrounded by concrete and is not moving anywhere, ever. I have no intention of securing the flange to anything except with the primed + glued PVC cement. It would be completely redundant to then screw into the concrete.

In post #23 OP has certainly proven that many people do recommend above finished floor and I'd never argue with this old house. I do know that in my case it wouldn't have worked, though; even with no wax the toilet just would not have sat on the floor. Evidently Alan found the same case in post #24.

I wonder if toilets are being designed differently. I find it hard to believe, but not all even work with the flange over finished, so putting it flush is safer, though as OP mentions it could invite higher change of failure in very certain scenarios, but generally unlikely ones or else we'd not still be using wax rings for this, or relying on them to keep sewer gas out of the house.


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## ben's plumbing

30 yrs in the plumbing field...we always secure to sub floor...tile around it...now you can set your flange hammer drill through tile so screws hit sub floor..you will be ok...ben:yes:


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## oh'mike

What he said!!!!:thumbsup::laughing:


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## TheEplumber

I guess I'm just a lucky guy.. Twenty something years ago I was taught to put put flanges on top of the floor for 2 reasons- my journeyman and code said so. Since I was a good little apprentice, I did it. We even installed spacers to accommodate for underlayment. I can only remember a few times the toilet didn't sit well. Odd, these instances have only been in the last few years. Maybe the toilet designs are changing... :huh:


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## Alan

TheEplumber said:


> Maybe the toilet designs are changing... :huh:


I'm pretty sure they are. I'm noticing it more and more.


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## Dave Holland

*Johnny Shims for toilet*

Perhaps the tile guy shouldn't have laid the tile so close to the flange so that you're stuck with this problem. A hammer drill with fresh masonry bit should do the trick at this point.

Try and get your hands on some Johnny Shims. They lock in place and do a great job protecting tile floors. I wouldn't use those little soft square shims. I've had those squish down and work their way out.

Here's a link http://ezshim.com/products/johnnyshim/how-to/how-to-install-a-toilet.html

Hope this helps.




bobmg said:


> I just had porcelain tile installed on my bathroom floor. that plumbers just use silicon caulk to "glue" the flange to the floor tile.
> 
> Does that sound right? I don't want the toilet moving around and cracking the PVC pipe over time. But I'm also not too excited about drilling through the tile.


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## bellycelli

*over the pipe and floor*

I'm in the same boat. A _contractor_ had a two man team do a shoddy job of pulling our toilet and replacing a patch of sub-floor and ceramic tile flooring in our bathroom--without noticing that the original, 50+ years old cast iron flange was broken. The toilet leaked the day after they left, and they were not willing rectify the situation without additional cost. 

We're going with a different _*plumber*_, who has been tolerant of our questions at every step of the way. *Plumbing* treatises, not contractor treatises, that I have read cite, "The pipe coming through the floor should be of sufficient length above the floor to be flanged over." (Standard Practical Plumbing, 1910)

The videos that I have watched about installation of old school lead caulked joints remove lead and oakum from between the soil pipe and the flange that sits over the soil pipe and tiled floor. Plumbers in those videos installed new oakum, poured new molten lead, and caulked the new joint such that the cast iron flange rested over the soil pipe and over the tiled floor too.

I suspect this laying the flange flush with the floor has to do with the introduction of plastic flanges prone to breakage in recent decades. I agree that if you bolt a flange to the subfloor and it fails, you may not see the damage until your joists are shot, because leakage cannot occur on the tile. Such a leak seeks an outlet below surface floor level to occur on tile backing or subfloor. What is worse is that such a leak may not be seen until the joists are damaged. Joist replacement is a far more expensive contractor call than enduring a plumber's grimaces and insisting on having the flange mounted over a soil pipe and tile.

Since we cannot find someone willing to pour a new, reliable, lead caulked joint--heat compression welding that does not necessitate bolting the flange to the floor--we are going with a cast iron twist and set flange. I do confess worry about the small diameter of the flange end that inserts into the soil pipe. Yet, the toilet's curved ceramic trapway diameter is smaller. So, it will probably work. 

We took our twist and set replacement flange to the hardware store for outfitting with appropriate stainless steel toilet bolts, floor bolts, and to buy a bit that matches the latter's diamond bit size. For precise floor bolt length, we realize the floor bolts will have to go through the tile, grout, adhesive, cement board, and partially through the subfloor.

When we asked, our plumber said he will bolt the flange down atop the tile for us. (I am learning to ask politely and look past grimaces to avoid making my own in paying to redo a bad job.) 

For our 125+ years old house, there is an added plaster of paris set for leveling the commode issue. Though the floor is not level, the commode must be. We also recently had our line snaked out to the sewer with imaging, because you can blow out your wax ring by plunging a clogged line. When this is done, we will limit the toilet for specific business only--no standing on it to change the 11 foot high light fixture, because that can blow out the wax ring too--given our uneven floor.


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## Ghostmaker

Use silicon caulk I guarantee your ceiling below will become very wet soon.


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## Peppe1019

Im a veteran plumber have done endless commercial and residential rough ins and the flange is always secured to the subfloor and should be flush with finished floor..whatever the sources are that say on top are totally incorrect and any REAL liscensed or journeyman oplumber will tell you that..


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