How To Get Closet Flange To Meet Finished Floor If ...

[Bird Doo Head]

When looking at closet flanges, PVC and stainless ring, for 3" schedule 40 pipe, I noticed that none would be able to meet the finished floor if the riser pipe was cut flush with the finished floor. (Excepting perhaps the inside-the-pipe twist & seal which I didn't look at)

The stainless ring type is flared out. In a 4" hole, it will stop about 3/8" above the floor. One needs a 5-1/8" hole for it to sit flush, but then there is no floor left for screws to anchor the flange.
Actually, that is enough of a rise that my American Standard's short skirt wouldn't allow spacer rings under the flange. It will hold the toilet in the air.

The PVC over-the-pipe one has a ring inside the socket that stops the pipe before the flange can meet the finished floor if the riser pipe is cut flush with the floor. It holds it about 5/16" above the
finished floor. In my case, I can use that and turn the ring off in the machine lathe. But, knowing me, there must be something wrong with that plan...

What's the normal rough-in procedure?
When roughing-in before the finished floor is installed, how do you guys know how high to cut the riser?
When the finished floor is in before you set the flange, and the riser pipe is stubbed up tall, how do you proceed?

Thanks For The Education!
Paul

 

[breplum]

On wood construction we start with the flange mounted and use spacers to match expected build up. Then plumb away from the flange.
In concrete pour we set the flange in place and use brass closet bolts upside down, bend them to make a "L" to act as anchor in concrete.

In a case like you describe but have never done, we'd use an internal pipe cutter to cut below the floor level as needed.

 

[GReynolds929]

They make flush fit flanges for this specific reason. Simple Google search brought up several options. Here is an example.

 

[Bird Doo Head]

Thank You both for helping.
Either the internal pipe cutter or flush fit flange will make this project very simple.

Thanks Again,
Paul

 

[turdchaser2000]

Thank You both for helping.
Either the internal pipe cutter or flush fit flange will make this project very simple.

Thanks Again,
Paul

Most of the pvc flanges that fit inside a 4” pipe will sit flush if the pipe is trimmed flush with the finish floor

 

[Bird Doo Head]

Thanks Again all for helping.
The pipe is 3" PVC & my hope is for an over-the-pipe flange for the largest opening possible.

Is it OK to cut the riser pipe flush with the underlayment?
The Ditra, thin-set and tile will cause the vertical riser pipe to end about 5/8" below the top of the finished floor. The flange will be able to sit flush to the tile if installed after tile is installed.

Will that gap between the top of the pipe and the flange cause paper to hang up?

(A sketch is attached to try to explain where my words won't.)