I was working in a duplex today and I was ready to install the toilet after putting in a new linoleum floor. I had pulled a layer of "luan" underlayment up and decided to float the floor out this time instead of using another sub floor. The problem is, the toilet flange is to high now and the toilet rocks on the flange. I never thought lowering the floor by such a minimal amount would cause problems with the toilet flange height. I have two questions: What is the correct installation height of the toilet flange relative to the finished floor? Is "shimming" the toilet my best option to get a good seal and keep the weight of the toilet off the flange? I have a feeling the builder installed the flange too high to begin with and me lowering the floor by the height of the luan just made it worse. Lowering the flange wouldn't be easy, as the access below the floor isn't great. Any ideas???????????

 

I'm not a plumber, but had the same problem. I called a plumber and had him check the problem. He gave me two options. Either he can cut the flange out and install a new one. but of course there was no guarantee that something wouldn't crack, leak, or have another problem. These second option was to shim it. I had him shim it.

Good luck.

 

Make a spacer(s) to raise the commode. Remove the commode, sit in on a piece of 1/4 in. luan plywood , scribe a mark on the luan around the commode base, mark your flange bolt cutouts and drain, jig saw them out. Lay your first piece on the floor at a 90 degree to back wall, scribe around it, silicone around flange bolt openings / drain and outside perimeter of spacer, This is to keep any sweating of fixture /floor mopping from rotting the plywood prematurely. You may have to make two spacers, if required height to raise fixture is 1/2 inch or more. Silicone around the outside to hide and protect the luan edges . If you dont like the cheaper luan method, you can build a mold to match the commode base and pour self leveling epoxy. Either way is not really the "right" way of doing it , but it will work . If you need to raise it a 1/2 to 3/4 in, it will probaly never be noticed. The right way. as you said, is to either bring the floor level up to make it flush with the flange as it is supposed to be, or worse, lower the drain pipe and flange ( not easy)

 

At this point of no return shim it... Toilets are shimmed all the time, no big deal. But a rocky toilet is a real bad thing that I see to often..

 

What was the thickness of the luan? The bottom of the flange should sit flush on the floor. While shims would work, it would be best to go below, cut and replace the trap, then the flange. Sounds harder than it is. However, you did say you have an access issue below. It isn't just the toilet on the flange but the water and moisture that the space allows, not good on a wood based floor. What is the current setup, Solderd lead and brass, or PVC?

 

exactly what greg said i do t his kind of work for a living and thats what i do when im stuck with that kind of situation

 

You can get (or make) a spacer out of plastic or micarda that should lift the toiled enough to let it seat proprely. Some toilets also have a deeper bottom rim just to fix such screw ups.

 

The luan was pulled out by someone else, but I looked at it briefly and from memory I'd say it was 3/16" to 1/4" (???). The toilet flange had one side cracked already so I'm guessing this may have been due to the improper flange assembly, or over tightening the toilet bolts. My opinion is the flange was set high by the builder, I've mounted a lot of toilets and never had this much trouble getting one to "seat". Furthermore, this toilet, is not original, it is a water saver and the building was built before they were used. Like daddymouse said, I think some of the older toilets had deeper bottoms so that would have compensated for the issue. Access below the floor is questionable, but time is the real issue. It's PVC drain work so lowering would not be to difficult, just set me back awhile and I have 3 other units to work on. I think I'll get a piece of 5/16 - 3/8" UHMV (ultra high molecular vinyl), scribe the base of the toilet on it and cut it to use as a shim under the toilet. UHMV is a fancy name for "non brittle" plastic that cuts easily and wouldn't rot over time. You can bet the next time I re-due a bathroom floor I'll pay close attention to the flange height before putting the floor in. The funny thing is we had the opposite scenario at my brother's house. After installing "durarock" and ceramic tile, the flange was to low. This problem is a little easier to fix, they make "spacer rings" to build up the height of the flange.