I went to replace an old toilet out in the garage and the flange cracked. It and the pipe are black plastic (PVC?) and the flange appears to be glued on. Whoever did this the first time did not mount the flange to the concrete floor, but the pipe does feel very sturdy with no wiggling. I'm guessing the right approach is to cut this flange out/off and glue another one on, or perhaps use some sort of a compression fit one? Not sure how to deal with the lack of usable floor to firmly mount to. Perhaps ignore it since it has worked this way for over 10 years...

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  • 1
    You can ignore the crack if there is no leak. The reason is that the plastic part is the spacer to provide a stable seat for the toilet as sometimes the actual flange(cast iron) was set too low that creates a gap in between. The crack will be sealed by the wax ring. Note, the plastic spacer shouldn't be glued to the pipe or cast iron flange, just let it sit freely.
    – r13
    Commented Aug 28, 2021 at 17:42
  • There's nothing under that plastic part, it is the flange. You can see the mounting bolt on the left with no counterpart om the right because is came up with the toilet, ripping apart the flange in the process.
    – Mastiff
    Commented Aug 28, 2021 at 17:49
  • Yes, exactly as I said, it is sitting on the flange to increase the height of the base. The sequence is - top of flange + plastic spacer = bottom of the toilet. Without the spacer, there will be a gap between the bottom of the toilet and the top of the flange (which was set below the finished floor).
    – r13
    Commented Aug 28, 2021 at 17:55
  • There is no other flange. The flange must have a mounting provision for the bolts, right? There is nothing else for the right side bolt to mount into besides the thing that cracked away.
    – Mastiff
    Commented Aug 28, 2021 at 18:12
  • Is there a cast iron flange below the plastic thing? If not, then it can be a screw-in type flange, and you shall twist it off and replace it with the same. zoro.com/oatey-toilet-flange-black-cast-iron-4-43653/i/G3787491/…
    – r13
    Commented Aug 28, 2021 at 19:02

1 Answer 1


You need to find yourself a "Repair Flange" or "Flange Repair Ring".:
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Images from Lowes

It fits over your existing broken flange and is fixed to the floor by using as many of the mounting holes as you can - preferably at least 4 IMO.

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