That "code check" book was written by someone using his opinions, it is NOT a plumbing code. There are "milllions" of flanges installed ON TOP of the flooring. The only ones even with the flooring are those in remodels or when the flange was preinstalled. It is NOT against code to put it on top of the floor, although it might go against the writer of the code check book, but I have never consulted him and do not know what his qualifications, if any, are.
I just made some nice money because the installing mope plumber installed the flanges level with the finished floor. One leaked, causing the subfloor to get wet and mushy. I ended up using spacers to get the flanges where they belong, on top of the finished floor. I have never seen a flange on top of the finished floor leak yet, or cause the toilet not to set flush.
Funny this thread should pop up. I have upgraded two of my toilets in my home. The 1st floor install went as normal. The wax flange with funnel locked the toilet in place where it would not budge. The upstairs install, (with the flange flush with the tile floor) went down fine however did not compress the wax nearly as well and the toilet could easily slide back and forth. Flash forward a month or two now, and I am have residual water coming out the side of the toilet. What I can only assume, is that the wax did not pinch down and over time the force of the water being funneled by the ring made it fall off the toilet and that superior Toto flush has so much water go thru it, it causes the excess water to go around the wax thru the 1/8th gap or whatever it is and end up next to the toilet.
I am off to HD to see if there are any thicker wax rings, or just to grab one without the funnel to stack with the one i have.
I have never had any problems with the flange being installed on top of the floor but to double check, I dry fit the toilet without a gasket. This way, you can check if the toilet is rocking because the flange is hitting the toilet horn.
If it is, the toilet flange HAS to be lowered because the addition of any gasket will make it worse and forcing the toilet down will essentially squeeze all the wax out.
I find a bad tile job a much more common problem for toilets rocking than a flange installed on top of the tile. If you keep tightening the bolts trying to eliminate the rocking without using shims, you will either destroy the flange or crack the toilet.
Another problem I have come across in the past is the plastic funnel that comes with some wax rings. If it doesn't sit properly into the flange or around the toilet horn, it can actually prop the toilet up causing it to rock.
I am new DIY here so please go easy. I just redid my second floor bathroom and installed tiles on the floor. I did install 1/4 inch hardibacker cement board over the original wood subfloor and then proceeded to install the tiles (1/4 inch thick) over it. My question now is this: When I removed the toilet, the flange is sitting above the original wood floor. It is still in good condition but now with the hardibacker, the tile and thin set , it now is below the finished tile by about 3/4 inches. What ar my options here before I install a new toilet? If I have to raise the flange, that means I have to cut it because it was glued to the pipe. I might have to call a plumber here as I am worried that I might mess this up. Your suggestions are appreciated. Thanks
A plumber has the tools that will cut the old flange out without messing up the floor. Then he can install a new flange properly. I would urge you not to try this yourself. You might find the cutter, but you might screw the whole thing up and have to call the plumber anyway. If you only a 1/4" or so, extension rings would probably work OK, but I think 3/4" is way too mucho. Also, don't use a wax ring with the plastic funnel. That's a gimmick that causes more problems than it could possible solve.
If there ever is a next time, the toilet flange lip is supposed to sit on top of the finished floor. Now that your new floor is in, that may be impossible without a lot of extra work. To raise it, it may be easy enough to do yourself if you have access from below. If cut from above, you have to have enough depth to either install a coupler, or a tool to bore out the old pipe from the fitting below (a RamBit is one brand). Depends on your exact configuration. Whether you feel up to it or not, only you know for sure.
Now, a waxless seal, Fernco and Fluidmaster both make some that might work for you...not the best, but should work.
If you ever had a leak, having it that low, it could leak into the floor for a long time before you knew it. On top of the floor, you'd likely notice the dampness. Now, a toilet shouldn't leak! But, then again, people buy insurance all the time just in case.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014
Thanks for all your replies. I will check the Closet Flange Spacer and the waxless seal. If there are anymore suggestions, please keep them coming. I will not install the toilet for another week as I am still finishing the rest of the bathroom.
Before I installed the tiles, I did try to see if I could remove the old flange. I found out that it was glued to the pipe. I knew then that I would have to call a plumber then or after I installed the tiles. If I had called the plumber before I installed the tiles, would he have done anything different than if I had called him now with the tiles installed. Of course I am assuming that he will cut the pipe and extend the flange to the finished floor.
BTW, are all original flange installations always flued to the pipe? I was just wondering because when a "professional tiler" installed tiles ( after removing the old linoleum) on my first floor bathroom I am pretty sure that it raised the finished floor. I am almost sure he did not replace the original flange when he installed the new toilet. I am just wondering now if there is a leak below the ff that I might not be noticing here.