toilet flange height

[Bartj]

I will be gaining about 3/8" with my underlayment and tile compared to the old floor. This will bring the tile just about flush even with the toilet flange. Will this be OK? Seems like it will if I use one of the larger wax rings and longer bolts if needed. I did see some flange extensions advertised and wondered if I would need them.

[John Bridge]

Hi Bart,

At most all you'll need is two wax rings instead of one. They sell a fat one at Home Depot that will probably do the trick.

[Bartj]

Thanks John. Sounds simple enough.

[Tom]

It will work and work well, although it will be contrary to Code, which puts the closet flange above the finished floor.

[John Bridge]

You are right, Tom, but there's always a possibility of seepage either way.

Bart,

When you caulk around the base of the toilet, leave out a couple inches in the back. The idea is that if a leak develops, the water will run out the back onto the floor where you can see it (maybe). If you seal completely around the base, it could be years before a leak is detected.

[Bartj]

Great idea. Always better to know you have a leak right away. I see where it makes sense to get the subfloor and tile under the flange and tight. This way if the wax seal leaks the water should run out on top of the tile. Using this theory the flange extensions would not help. Wouldn't it make more sense to manufactur the toilet with a longer waste neck that would extend further into the waste drain?

[John Bridge]

No, I don't think so. I've had problems with toilets leaking where the flange and toilet waste were too close together, thus squeezing most of the wax off to the side. I think a certain amount of wax may be better, but my thoughts have no science behind them whatever.

Bart

The part you are thinking about is the "horn", and it would be good if it went a little farther down the pipe. Practically speaking, though, I think they would get broken a lot of the time once the toilets are out of the box and before they are set. With the horn sticking down farther than the base of the bowl, it's inevitable that the things would get knocked off.

[Bartj]

Thanks guys. John, your experience is worth tons more than any theory I may have. That's why this is a great site and my project will turn out well. Thanks.