Toilet Flange Too High

Hi All, First time poster here.

I am remodeling my bathroom and have gutted everything to studs and subfloor. When I initially removed the toilet, there was a thick bed of mortar propping up the toilet. I found it strange, but quickly learned it was because the toilet flange was about 1/2” above the finished floor. Well, now I have removed another inch of floor and the toilet flange is 1.5” higher than the subfloor. The new finished floor with be tile on 1/2” cement board, leaving the current flange about 0.75” too high..

How can I lower this thing? The current flange is a female flange that is glued on the outside of the drain pipe. I considered just cutting the flange off and cutting the main drain pipe down and putting in a new flange on the now lower pipe, but everything I’ve read says not to cut into the main drain pipe (not sure how true that is).

What are my options? Any ideas on how to lower this thing?



Thanks!!

What diameter is the drain line?

It’s pretty easy to neatly saw off the old flange, then install a new flange that slips inside the drain and seals with rubber.
Then it screws down to the new subfloor.
You can also run the new flooring under it first, so it is not too low. It depends on new flooring thickness.

You can find these types of flanges anywhere.

But sometimes that leaves a pretty skinny drain.

Your old tile floor was probably set on a thick mortar bed, maybe in the 60’s or earlier.

For example.

Oatey PVC Twist-n-Set Open Flange

https://www.homedepot.com/p/100062268

Thanks Jeff. Drain line is only 3”. Would I be ok still using a flange that goes inside a 3” line?

This would work.
Glues onto the outside of the abs drain pipe.

You might need to carve a small channel through the subfloor around the drain.

You might have to knock off parts of the old flange socket with a chisel, to fully expose the pipe to cement on a new flange socket.


Oatey ABS Open Flange

https://www.homedepot.com/p/202819707

This will also work, but creates a fairly skinny drain.

A wax ring with a plastic horn will not work on this flange.
Otherwise, it should be fine.

It slips inside three inch ABS, no glue, rubber seal.
Screws down to subfloor, or through tile into subfloor.


Oatey ABS Twist-n-Set Open Flange

https://www.homedepot.com/p/205855426

If you have a rare toilet with a trap way bigger than 2 inches, this might be a skinny drain situation.

You can always contact Oatey customer service for info.

Gluing on the new flange outside the shortened pipe, like you have now, would be slightly more complicated but would allow greater flow, less chance of clogging from massive loads or tons of toilet paper.

Thanks Jeff, I’d like to do this correctly, so I’ll avoid the skinny drain situation. So if I’m understanding correctly, I should cut away the current flange from the drain line, Cut drain line down to desired height, then install new flange over drain line?

Im guessing the hardest part about that will be to cut away the neck of the flange away from the drain line. But if I’m careful, it can be done with no damage to drain line.

Would it make sense to cut the drain line to lower it, or would I just push a new flange further down on the drain line? Not sure if there’s a stop on the newer flanges or not.

Cut right directly parallel at the underside of the flange, to get that out of the way.

Now the old socket is still in the way, and the pipe inside it is still too high.

You can dry fit some new subfloor and tile next to the pipe, to estimate correct exposed length of pipe.
Allow for adhesives, thinset mortar, whatever.
Having the drain pipe sticking up a tiny bit into the flange is common, but it grabs tp and causes log jams.
Better to be exact right height, or an 1/8 inch short, still plenty of socket to hold everything.

I have only cut away old sockets a few times, but slow and steady wins the race.
You crack something, you are screwed.

When you eventually glue on the new flange, use plenty of glue, and rotate while pushing down, that will send some softened abs into the smaller nooks and crannies.

You will probably want to carefully cut almost all the way through the old socket, in many places, close together, leaving maybe 1/2 inch or 3/4 inch strips.
Don’t gouge into the pipe, do fancy shaving.
Let the bevel side ride down the pipe, like a sled.

Buy a cheap 3 inch elbow fitting with same socket depth, to use as a guide to progress, it will be easy to twist on and off.
Don’t go on too far, it might stick.

Taking off big pieces can tear out pipe surface.
A few small missing chunks here and there will probably not leak.

An oscillating multi-tool is great for cutting the sections.
With a rectangular wood cutting blade, you can really see what you are doing, and the front face is straight across.
You can even mount the blade at an angle, so the blade is cutting while parallel to the floor, perpendicular to the pipe.

Harbor Freight has a single speed model for about $18.00, with the coupons they post every week.

DO NOT cut too far, cutting through the socket and into the inside pipe might cause fatal leaks, or maybe cement and good luck will fill them up.

You can clean up small bumps and blobs left on the pipe surface with a smooth flat file.

The drain pipe length (and new flange height) will ultimately be lower than now, so you will probably have to widen the subfloor gap to finish chiseling, or to apply primer and cement.

Members who have more experience with this than me will hopefully add their tips and advice!

Jeff, thanks for all your advice.. I ended up just building up the floor, 1/2 plywood on top of subfloor, than 1/2 cement board, then tile. Ended up at basically the right height.

That works too!