Freestanding toilet flange

[watertight]

I installed a new toilet a month ago. The subfloor underneath the toilet was rotted due to a leak, so the floor was replaced. The old floor had a circle cut out of it that was slightly bigger than the flange, allowing approximately 1/4" gap between the outer edge of the flange and the subfloor. When the subfloor was replaced, we cut the same size circle.

Now the toilet has a small leak when flushed. I have been doing research that is telling me the flange has to be bolted into the floor. If this is necessary, is there an easy way to get new subflooring under the flange or does everything have to be ripped out?

It looks like the flange is at the right height and that if I could just slip subflooring under it I would be able to bolt it down, but I realize things are rarely as easy as they sound. I have full access to the plumbing and subfloor from the basement if that helps.

Any advice will be appreciated!

[jimbo]

We can't tell if this is the cause of your leak. But , the flange really should be supported. It is supposed to sit on top of the FINISH floor, so it may still be a little low, but that can be dealt with.

SInce you have access from below, you could sister in some joists as necessary to support some plywood which could be cut to fit in around the flange for support.