You can try chipping concrete under the flange and replacing the bolts with longer ones, or use a red repair ring, rotohammered into the concrete to hold new bolts.
It will take two wax rings to seal.
Greetings Plumbing Fans,
See below for pix, I've got a closet flange that now sits about 1/4 to 1/3 in below the tile. The flange itself is embedded in the concrete of the basement on a slab. When I went to set the new toilet down, the wax ring didn't make significant contact and the bolts don't extend up high enough to be grabbed by the bowl to floor knobs.
Should I be planning to chip that flange out and install a riser of some sort and a new flange? Can I install a second flange on top of this one to hold new, longer T-Bolts, then cut down the too-short bolts? Maybe just an xl wax ring?
Diameter of the pipe at the top looks to be 3.5" but widens to probably 4" a couple inches down. Slab (and probably the pipe) were laid in 1959.
Thanks for the help! Here's the way I ended up fixing it. Used a brass ring + lead Dutchman. Toilet install thereafter went normally and smoothly. No sign of any issues after 48 hrs. See any red flags?
They sell those parts in Seattle.
It isn't really a gas tight seal from the pipe to the lead. My preference is to use the red ring, which sets farther out, and allows the wax to totally seal from the floor to the casting on the bowl.
I bought on of those brass ring and lead sleeve kits, but couldn't see a way to seal it. It just sets over the drain.
But if you're happy, then I'm happy.
I hope you used a silicone sealant between the new and old flanges. And I would have put the new bolts UNDER the cast iron flange and then used them to clamp the two flanges together.
Thanks for looking out for me... and oh, yes, silicone sealant is my friend. Used it between the flanges and all over the contacting surfaces of the dutchman, too. With regard to the old flange I wasn't able to do anything other than grind off the old bolts - the old flange ring was set flush into the concrete of the slab. As I saw it, my options were to leave it in place or chip it out. I appreciate the expertise from y'all!
It would not really have been too difficult to cut the concrete needed to remove the old bolts. We do it all the time when the original flange and bolts were poured into the concrete by "incompetent" plumbers.
Aparently you need a new flange. I saw a lot flanges on this site. Hope you can find a suitable one. Cheers!