PVC toilet flange setting height on subfloor

[Branimal]

I'm trying to figure out the ideal height to set the flange. I'm using 1/4" cement board, 1/4" mosaic tile., 3/16 mortar. No mortar under the cement board - I'm just going to fasten them with screws.

The flange is 1/2" thick. Would sliding some 1/4" cement board under the flange suffice? That would leave the finish tile flush with the flange.

BTW - I know there is some argument about flange to finish tile height. I've never had a problem with flush flanges with modern kohler, AS elongated toilets. I have had some wobble issue with proud flanges.

Nothing is glued up yet.

 

[Reach4]

I would go with a closet flange with a stainless steel ring if gluing in. The ring, metal or plastic, should set against the top of the flooring.

Can you put off attaching the flange until the finished floor is in? That is best.

Depending on what you have going on with your piping, you may be able to use a compression flange (no glue). Those have the advantage that you can re-do. In your case, you would probably consider an inside-compression flange. How much vertical piping do you have below the floor?

Even better would be an outside compression flange, but that would probably require you to trim your subfloor.