Hello and thank you in advance for your help,

I started a remodel of a bathroom and just finished lifting up the old floor (1" of mortar + thin ceramic tile over 5/8th plywood). The wood around the back part of the bowl was wet (not yet rotten, but wet about 1/2 way through) so I removed it.

I started doing the math on how much more subfloor and cement board I would need (replacing the 1" mortar) and put a level on the flange to measure. It was not level. To make it level, I needed to lift it by almost 1/2 inch. (Also, still not sure if the flange should sit on the finished tile or even to it. Did not pay attention to the way it was before the demo. Would appreciate any help on that as well.)

It did take some strength (mainly on my fingers) to get it to level. I looked at the hole in the joist (lucky I removed the wet wood to have access) and the PVC pipe was not hitting the top of the hole.

It looks like the much of the stress (after it was leveled) would be on where the flange is attached to the PCV pipe. Actually, I can only see the flange and the pipe running through one joist, so I am not sure what is going on furter down the line.

My question is how strong is the bond between the flange and the PVC pipe after they are glued together? Would I be safer to leave it unlevel (maybe just lift it 1/4" and shim the high side) and let the wax ring make up the difference? Pulling it half way up was less stress.

Appreciate any advice.