Warped Toilet Flange

[depawl]

I know this is a common problem and I've scoured this and other forums but have yet to find an answer. After removing an old toilet I discovered that the PVC toilet flange was warped, undoubtedly due to the previous owner over tightening the flange bolts. I've now tiled the floor and need to install a flange extender. My concern is that due to the warping of the existing flange there will be a void under the extender. So my question is how best to address this?
I know there are several brands of extenders to address problems of this type, or would filling with silicone (or some other material) under the extender be a possible solution?
The photo doesn't seem to adequately depict the problem, I'd say the flange is warped about 1/4 to 3/8 of an inch at the flange bolt locations.
Thanks.

 

[Reach4]

You could put on a repair ring.

Sioux Chief 886-MR is not split. It wouldgo over the top of the PVC, and you would screw it down .
https://www.siouxchief.com/products/drainage/residential/closet-flanges/spacer-repair/ringer

There are other repair rings available. Some can be held down with screws outside of the existing ring through your new tile. But then you would have to drill the holes through your tile.

 

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[depawl]

I was concerned that by screwing down the repair ring it would also become warped, or if it wasn't screwed down tight then there would be a void between the flange and the repair ring.

 

[Reach4]

The purpose of the repair ring is to supply tension the closet bolts by keeping the bolts from pulling through the PVC or bending up the PVC. The ring is stainless steel, so it will take a fair amount of force to bend that significantly. I don't think gaps under the repair ring would be a problem. Since your PVC is recessed, you will not interfere with the toilet reaching the floor. You could even put the t-head of a closet bolt in a gap if that works better for you.

If you wanted things pretty and flush, you would have to take a belt sander to flatten the PVC. Nobody else is going to see it, so don't let gaps bother you.

Screws hold the repair ring down. You can pull the existing screws from the PVC, and screw the repair ring into the same holes, or you can drill new holes. Just pay attention to make sure you can get the closet bolts where they need to go.

 

[Jadnashua]

Your better choice would have been to replace the flange prior to installing the new tile...too late for that for good effect.

If your drain plugs, you want to ensure you have a good seal. Also, if there are any gaps, they can let sewer gasses into the room constantly. So, you do need to seal the repair ring to the existing flange. That could be wax, or silicon.

 

[Reach4]

Also, if there are any gaps, they can let sewer gasses into the room constantly. So, you do need to seal the repair ring to the existing flange. That could be wax, or silicon.

Not so. The wax seals to the PVC inside of the repair ring ID. The repair ring holds the toilet in place, and does not have a sealing function.

 

[depawl]

I was wondering about grinding down the high spots on the existing flange with a belt sander. I was concerned about weakening it, but maybe I'll give that a try.
Also is it recommended to apply silicone to the existing flange when adding a metal repair ring of this type?