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How to Handle Copper Toilet Flange Being too low to Tile Under

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Aug 11, 2013, 07:31 PM
How to Handle Copper Toilet Flange Being too low to Tile Under

I am remodeling an old bathroom and have ran into a situation I wanted to bounce off the experts in the forum.

Please refer to the attached photo...

The build up is taking place on top of a 1.25" wood sub-floor. I have laid down the backer board on top of the wood. Then, put the tile on top of the backer board. As you can readily see, there is a perfect fit! That's exactly the problem, since there is no space for the two layers of needed thinset. Per my calculation I will need 2 layers of 1/8" thinset, for a total of 1/4" space!

The flange is vintage circa 1960s. It is connected to cast iron piping, with access from below in the basement.

Is it OK, if I tile flush or slightly below the flange, but not have the flange rest on top of the tile? If I do so, do I need to build up below the flange somehow, so the flange is resting on something?

By the way, how would you go about cleaning the old wax off the flange?


Aug 11, 2013, 10:46 PM
Well, the good news: this as about as perfect as you can get. There is nothing wrong here.

The tile does not go under the flange, instead, cut the tile so that it butts up close to the flange edge. Fill any voids with thinset. the tile to flange joint does not have to be pretty as it will all be covered by the toilet after installation.

BTW, your backerboard doesn't have to go under the flange either, although it doesn't hurt if it does.

As for the old wax, an old scraper will do a good job. You don't have to remove all the wax, just most of it. Use gloves, it's nasty stuff. Yup, that's why.

Aug 12, 2013, 05:49 PM
Thank you, Jaybee. I suppose it is OK, if the flange ends up being about 1/8" higher than the tile butted up next to it. It will get covered by the toilet, anyhow. How secure do I need to make the flange to the floor? Currently, there is about 1/2" space between the subfloor and the bottom of the the flange (taken by the 1/4" durock and 1/4" tile). Should I
1. take the Backer board off and fill the 1/2" void with 1/2" plywood of some sort?

2. Put the thinset under backer board and keep them under the flange? Do I need to worry about the 1/8" void I will have under the flange, since tile is not in there any more?

Aug 12, 2013, 05:56 PM
having the flange 1/8" above the level of the tile is OK. 1/4" would be OK too. The flange does need to be secure though as the flange is the only thing holding the toilet. I would just make sure that the flange is supported either by the backer or a combination of the backer and thinset.

Aug 13, 2013, 11:29 PM
The flange needs to be supported and also screwed down. Typically 3 blocks of wood are used, but use whatever is the right thickness. You said 1/2", so use 1/2" spacer and screw the flange into the subfloor.

Ideally the bottom of the flange should be at the level of the top of the finished floor as you first stated. But a flush or even low flange will work with the use of corresponding wax seal ring or spacers and wax ring.


Tile 4 You llc - Troy, MI
Kerdi shower specialist - Ditra installs - Product-Method suitability consultation. I have NEVER made a mistake, I thought I did once...........but I was wrong!
Aug 14, 2013, 04:26 PM
if your tile goes OVER the level of the flange, not to worry.. there are plastic flange rings that you can screw down through the other flange holes. I recommend you use some mineral spirits and rags to clean the flange shiny clean in that case, and run a bead of silicone between the flange and the spacer ring to insure water tightness. use a wax ring with the little plastic funnel when you reset the toilet, and that should be good.

be way careful and be sure the tile is level across the flange area. we somehow got something under one corner of one tile in our main bathroom, and had a little leakage problem for a while, until we shimmed the toilet. if I'd had a 4-foot level when setting the tile, it would have saved a lot of fooling around.

sig: if this is a new economy, how come they still want my old-fashioned money?
Aug 22, 2013, 01:22 AM
when screwing a flange to the floor you MUST use brass screws. not steel screws not galvinized screws but BRASS screws
the acid in pee pee eats up screws and rusts them out PDQ. brass will last a lonnnnnnnnng time
after you set your toilet... grout the base of it to the floor. or use caulk... i prefer grout.*****?v=vn7bkncf1_E