Toilet flange not flat against the floor

[Nelsonba]

I'm installing a new toilet flange and it doesn't sit totally flat with the floor. Part of it does, but the other side is raised about 1/4". Is this going to be a problem? If so, how can I correct it? If not, do I need to support the other side with something? A shim perhaps?

Thanks

 

[Gary Swart]

I will be a problem. If you just shim it, then the toilet will not set level on the floor and will have to be shimmed a whole lot more than 1/4"! What you should do is redo the drain plumbing so that the flange will be level. If you don't, and just try to do cosmetic repairs, you will be plagued with problems.

 

[Sponsor]

 

[Nelsonba]

I did set the toilet over the flange to see if it was a problem. It wobbled a little, but not much. Will this work?

 

[Mikey]

Probably not. Sounds like the flange sits too high off the floor. With no wax ring in place, the toilet should sit flat and firmly on the floor when positioned over the flange; no wobbling allowed.

If you tip the toilet bowl and place a straightedge across the trapway to the edges of the bowl casting, you will see how much room there will be for the flange and wax ring; do the same trick with a straightedge across the flange and measure the distance to the floor. Do the math.

If either the place-and-try method or the measurement method indicate there isn't enough room for the wax ring to smush out (around 1/8" or greater, I'm told), you've got to either a) lower the flange, or b) raise the toilet.

 

[Jadnashua]

Wax isn't a spring, so if the toilet doesn't sit flat on the floor, the wobble will break the seal. Toilets are designed to have the flange sit flat on top of the finished floor, and be anchored through it into the subflooring. Anything else is just asking for problems, both short and long-term.

 

[Nelsonba]

The toilet doesn't wobble because the flange is supporting it. It wobbles because the floor isn't completely level. Can't I just shim the toilet?

Would it make sense to take out some of the tile on the high side so that the flange sits on the morter bed below it? This way it would sit on top of the finished floor on one side and the morter bed on the other. It still wouldn't be level with the floor obviously, but I would think the wax seal would bridge any gaps.

 

[Jadnashua]

It doesn't matter what the reason for the wobble...when the toilet moves after installing the wax seal, you will end up with a leak.

 

[Nelsonba]

I don't plan to let it wobble after I install the wax seal. I will shim it so it doesn't move. I can't imagine that every time a toilet has ever been installed, especially over tile, that it hasn't needed a few shims here and there.

 

[Mikey]

As long as you're sure there's room between the toilet and the flange for the wax, you can shim the toilet. They make plastic shims that work well -- HD carries them for a couple bucks a pack. I'd place the toilet, shim to level it, and tape the shims to the floor so they don't move. Then remove and replace the toilet, with the wax ring in place, back down on the shims. Snap off the portion of the shims protruding from under the toilet. (You can also cut the shims before placing the toilet if you'd rather, but the plastic shims snap pretty clean.) Caulk around the toilet, leaving a gap in the back (or not -- depends on local codes and your taste).

 

[Nelsonba]

I was able to level the toilet by shimming it. Did what you said and dry fit it first and then taped the shims in place. No wobbling and no leaks. Thanks!