Closet flange/Waste pipe overlap

[DallasDIY]

I'm posting this so I only have to do this once.

I have another thread running about my subfloor replacement. I've done all the subfloor and laid the new vinyl. The top of the 3" waste pipe is 3/4" below the finished floor level.

I have a stainless steel 4x3 Sioux Chief closet flange that will go around the outside of the waste pipe. The flange downpipe will extend 2-3/8" below the finished floor and this seems to be a bit longer than some other flanges I've seen.

This means the maximum potential overlap of the flange pipe with the waste pipe is 1-5/8"

Naturally, the dry fit is snug and things will slide much easier with everything primed and basted in cement.

My question is: Just how far will the closet flange go when I goop things up and push it down over the waste pipe? Should I expect the flange to easily end up flush with the floor? Do I need to trim a bit off the bottom of the flange downpipe? I simply don't want to press this on and end up with a gap between the flange and the floor.

Thanks up front for the input!

[hj]

It will slide as far onto the pipe as necessary to end up on top of the floor, UNLESS there is something on the pipe, or a fitting, that will impede its movement.

[jadnashua]

Put another way, once you prime and apply the PVC cement, you can install the fitting all the way to the stop. So, measure the distance that the pipe would have to insert into the fitting to have it sit flush with the floor. If it is sticking up less than that, you will be able to get it to sit flush. Keep in mind that this is an interference fit...unless you hold things in place while the cement solvent dispurses, it is possible that it will slowly creep up. Best to have the screw holes ready and hold it down while you get a couple in, or set something quite heavy on it for a bit.

[DallasDIY]

The pipe and the flange are extremely clean with no burrs or extraneous items. There is no "stop" (except for the flange hitting flush on the floor) and all the measurements are fine and the fit will be okay--not too long and not too short. Once I reach floor level, I'll hold the flange firmly flush against the floor for several minutes to avoid creep while the cement sets up.

Thanks for the confirmation.

[DallasDIY]

Well, I guess there ARE some stops on the inside of the flange--three small ones around the edge to stop the waste pipe. Fortunately, I was well below those stops with the top of the waste pipe.

The flange slipped on like butter and I held the flange as close as I could to flat/flush on top of the finished floor since the waste pipe was a little bit off plumb. (I knew this going in.) Left and right, it's precisely level. Front to back, it's just about 1/8" high on the front of the PVC part of the flange even though the ring is screwed down flush and tight all around.

I expect the slight out-of-level situation will not be a factor in leaking since the wax ring should/will adjust for a good seal. I'll dry test the toilet to make sure it doesn't rock and will shim, if needed.

Thanks once more for the help.

[Gary Swart]

Set the toilet over the flange without the wax ring and check that it sets firmly on the floor and that there is no rocking. If there is rocking, then determine where the low place is and how much shim will be needed. If the floor is level and the flange is set on top of it, there should be no movement at all. Once all of this is determined, go ahead and set the toilet on the wax ring.