Odd size toilet drain

I paid a plumber a few months ago to add a drain for a shower and also to add a toilet flange to my rough in drain. I was getting ready to set my toilet and happened to look more closely at the toilet flange (I had it covered up while I'm doing construction) and noticed it looked small. As it turns out, the flange opening is only about 2.5" wide. Most of the wax rings I see in the stores are designed to fit 3-4" flanges.

My question is: is a 2.5" flange common? The flange itself is a Sioux Chief, and it is definitely a toilet flange (he didn't get something different and install it incorrectly). If this sort of flange size is ok, who makes a wax seal (or other type of seal) for it? I mainly shop the Home Depots and the Lowes and they don't carry anything less than 3".

It sounds like he used an inside mount flange on a 3" pipe. He did you NO favors at all. Was this install inspected? The better way to do that would have been to use an exterior flange, which would have given you the full diameter of the pipe (3" is the minimum drain line diameter for a toilet). If the pipe came up through a concrete slab with no space outside it, it was the easier path, but cracking some concrete to get an outside mounted flange isn't all that difficult.

Note, though, that on most toilets, the interior pathways are usually less than that (a little over 2" is fairly common). There are only a few that have bigger trapways (the Caroma has a 3" trap, and if used would be a problem).

Your description sounds like exactly what happened. When I moved into the house, there was pipe coming up out of the concrete floor about 6 inches with wax (or some sort of plug seal to keep it from being smelly) in it.

I did measure the interior of the toilet and can tell you with 100% certainty, that is is much less than my flange opening (I think it is right at 2", or slightly large, but less than my flange opening).

At this point, I've already laid tile. Is it possible to use this? Or do I need to go back and rework it (break concrete, tile, etc). I was hoping I can find a seal that will work. I also may be able to use just a plain jane wax ring (without the built in gasket...the gasket is what won't fit in the flange).

The thing that ticks me off about this is that I paid this guy to install a shower drain, precisely because i did not want to break up concrete for the shower drain. I paid him to do the toilet and the pex because he was already working on the other stuff. He broke up concrete for the other stuff the same day!!! How lazy!

flange

The wax ring seals to the flange, not the opening so it will give a proper seal. BUT, the undersized outlet can give problems. It is probably a little worse than the wax rings with funnels that most plumbers avoid like the plague.

hi, thanks for your response. I am a little bit unclear on what you mean:

If I understand what you are saying:
- most plumbers avoid the rings with the funnel/gasket
- i am better of using just the wax ring?

Note: to my knowledge, the ring with funnel/gasket is not even an option to me because I've not seen one that will fit into my little 2.5" opening. They fit into 3" openings only.

My hypothesis is that since my flange is larger than the outlet from the toilet itself, any waste that goes down there is going to have to first pass through the toilet pathway.....so in theory, i shouldn't have a problem right?

I'm just trying to figure out how to seal the flange and what product to use.

It is never wise to use an inside fitting flange on a 3" pipe, but since that was done, there are some options to consider. The flange can be replaced by a professional plumber without damaging the floor tile, but it would be an added expense. Because it is not absolutely certain that this will cause a problem, you could wait until there was a problem. "If it ain't broke, don't fix it" would apply here. The expense of changing the flange would be the same either way, so I'd give it a chance. Some genius who probably never set a toilet in his live dreamed up the idea of putting a plastic funnel or cone on a wax ring. Unfortunately, it really looks like a good idea at first glance, so the uninformed homeowner will pay more for this feature. In reality, these horned rings cause far more problems than they fix. There are two options with sealing a toilet. What I call a "Plain Jane" wax ring, meaning just a ring, or the waxless ring. Either works well.

thanks for the feedback. It is really excellent. I'm going to try the "plain jane wax ring" and watch it real closely. As you stated, there really is no big risk other than a potential backup. Since I expect this to be a lightly used bathroom (it IS in the basement) we should be ok.

Your only choice of seal is plain wax...a waxless won't fit into a 2.5" opening of an inside fit flange, just like the wax with the funnel won't.