What to expect when I pull up this toilet?

[Bill_C]

I found an intermittent leak and determined that it is coming from the toilet, either the seal or a leak from the underside of the toilet. I cannot rock the toilet but can rotate it. The leak has probably been going on about a month now. It rarely drips down the drainpipe but it appears that the subfloor has been soaked....there is a spot drilled from the bottom through the floorboards into the subfloor about a foot away from the toilet and the subfloor is wet there. There are at least two layers of tiles over the plywood? subfloor. I have changed out a wax ring before but this may be a little bigger of a job than that. I wonder if the toilet is rotating because the floor is rotted at the flange? Are there any plumbing items that I should have at hand (besides a wax or wax free ring) before I pull this up? Specialty flange that repairs rotted floors on contact or such? What should I be looking for under the toilet itself to rule that out as a source? I'll have to be prepared to replace some of the subfloor and would like to have needed plumbing parts at hand before starting.

[jadnashua]

The flange must be well anchored to the floor, then the flange bolts must be held into the ring on the flange to hold the toilet. Either the flange is broken or the bolts came out of the slots or the bolts just rusted out (use brass or SS next time), or you would not be able to rotate the toilet. In either case, movement of a toilet after you set it will break the wax seal and allow a leak.

You may need a repair ring for the flange, or it just may not have been screwed down in the first place. Or, you may need to replace the riser and put a new flange on. Hard to tell without seeing it.

Ideally, the flange is installed on TOP of the finished floor, and anchored down through the it into the subflooring. This provides the toilet with a well supported, and anchored flange that will hold the toilet and allow a seal to be robust.

You may find the floor rotten, and may be in for a major repair. If the floor is intact, it will eventually dry out if you can fix the toilet flange and get a good seal to stop adding moisture to the subflooring.

[Probedude]

Question on the whole idea that the flange rigidly locates the toilet in place.

This is a myth correct? Other than the cast iron flanges (and even then not very well) I can't see how the stamped stainless rings do much to keep the toilet in one place but instead try and keep the sewer pipe attached to the toilet.

Am I wrong?

Now if the toilet were bolted to the floor itself then I could see that it would be better secured, but still with the clearance between the porcelain and the bolt holes the toilet the toilet can be rotated if you tried hard enough.

[gardner]

Question on the whole idea that the flange rigidly locates the toilet in place.

If the flange and flange bolts do not keep the toilet from moving around, then there is not much else but caulking (on most toilets) that will do this job. The flange must be securely attached to the floor and then the flange bolts snugged up to hold the toilet in place.

the toilet the toilet can be rotated if you tried hard enough

The toilet is supposed to be caulked around the base, and this will help keep it in position. Until caulked, if you really try, you can move the toilet a little, and thereby break the wax ring seal.

[jadnashua]

On most flanges there are 4-6 #10 or larger screw holes...if you properly fill them with the designated screw, the ring isn't going anywhere. That holds the bolts, and the bolts hold the toilet. Except on a smooth, hard floor, there is then usually enough friction and tension to hold the toilet to the floor - caulking adds sanitary and additional sealing/adhesion properties.

[Gary Swart]

Actually the caulk around the base of the toilet is only to prevent spilled water from an overflow from getting under the toilet. The ring on the flange is supposed to be oriented so the flange bolts are in the correct position then screwed through the finished floor and into the sub floor. I use #12 stainless steel screws for these anchors. Depending on the drain pipe material, the flange is either solvent welded or leaded to the drain pipe. This seals the connection and also helps hold the flange in place.