Extending PVC Toilet waste pipe

Hi all...First time poster here. I'm remodeling a half bath on the first floor. my toilet flange was resting on 1/2 plywood. I ripped out that plywood and will replace it with 3/4" ply. Now, obviously, i cannot put the new ply underneath the flange because there is 1/4" difference from the previous floor. I do have access to the drain pipe in the basement. Everything in question is PVC.

My question is this; Can I cut the drain pipe below the floor and then install a Fernco Flexible coupler to it so i can extend it the 1/4" that it needs to rest on the new subfoor? Does it matter if the two ends, where the pipe was cut, do not meet each other inside the Fernco? There will be a 1/4" gap between them.

Any help or advice would be greatly appreicated!

Thank you in advance!

-Scott

What is the finished floor going to be? The proper place for the flange is to sit on top of it, which may be even higher!

You aren't supposed to use that connector above ground...use a no-hub connector instead. I'd probably cut off what you have and install new and glue it all. You should not have any gap in the connector. On the no-hub, there is a slight ridge to tell you when it is bottomed out, and each side should be up against that ridge. Now, will you have a big problem? A gap would give things a place to catch. May not be an issue, but it's not right.

It would probably take longer to try to remove the old flange, and that can be messy, since it is solvent welded in place. Can usually be done, though, and may leave the pipe less than perfect. Best to replace.

the tile i am putting down is 3/8. If the flange is supposed to sit right on top of the finished floor, which would be the tile, how do you screw the flange down? You don't screw it through the tile, do you?

The easiest thing to do is to notch the tile before you lay it so you don't have to drill through it, but yes, the flange is supposed to be on top of the finished floor. Most pros prefer a flange with a ss ring rather than an all plastic one.