spigot-style flange that fits into 3" hub: waxless seal options or toilet options
Because of some structural issues in the floor joists due to long-term moisture damage, we had to sister the waste-pipe bay joists with LVL, reducing the cross-section space between them; a 4" waste elbow wouldn't fit inside, and we had to transition the 4" waste pipe to a 3-inch elbow. Maybe there were other options but that's the way it is now.
I have a spigot style toilet flange which would get solvent welded into the hub of the 3" elbow. Dry-fitted and screwed securely to the plywood subflooring, the rim of the flange is a little shy of being perfectly flush with the tile.
I should be good-to-go, but the 3" spigot flange isn't perfectly compatible with the Fernco flexible black rubber waxless seal. The seal sits a smidgen, maybe just 1/8" inch too high, and the toilet rocks slightly. A Fluidmaster hard plastic waxless sits even higher in the spigot flange.
I cannot lower the waste pipe. Wish I could, but the supports on which it's resting are inside the patched foyer ceiling.
Before I resort to a wax seal, or install a thermoplastic gasket to raise the toilet up a tad, I'd like to know if there are other waxless seals that might have a slightly lower profile. Is there one that's made to be more compatible with the spigot-style flanges?
If not, are there toilets whose horn is higher off the floor? The horn of our Kohler toilet is pretty much flush with its base. I was unable to get drawings that contained any detail about a toilet's horn. Are they all the same?