abs closet flange is 1 and half inch lower than floor. the flange inlet is ID 4 inches. I am thinking of use some abs cement to glue a new abs flange into the existing one. (I assume 4x3 flange can go fit snugly into a 4 inch inlet?) I did some google search but have not found anyone recommending doing this. Would it work?

  • Doubt it would last even it you could get a good bond.
    – keshlam
    Commented May 8, 2015 at 12:33
  • You can buy spacers and longer closet bolts to overcome the difference. You wouldn't want to add another flange over it. Commented May 8, 2015 at 20:18
  • so the spacers actually extends the existing flange to the floor level? How is that different from cementing a new flange? It appears that cementing a new flange provides a water-tight air-tight connection. However I am not sure how the spacer can create a water-tight connection with the old flange. Maybe put some wax or rubber gasket between the old flange and spacer? Commented May 8, 2015 at 20:36

2 Answers 2


Usually if the flange is not high enough, a larger wax ring is used or stack two wax rings together. Yours sounds like it is lower than any I have ever encountered. A good plumber with an internal pipe cutter could cut it with out damaging the floor, add a coupler, and with some proper material to hold the flange at the right height, reset a new flange. Seal that to the surrounding finished floor, so if the wax ring DOES leak, it will show on the floor, not go down around the pipe.

  • ok if cutting off the old flange then the new flange can be cemented to the pipe. what would be the difference between cementing to the old flange vs cementing to the pipe? Commented May 8, 2015 at 18:20
  • Cementing it to an unclean inside diameter of the pipe, unless you can get it clean. A smaller diameter pipe for the actual drain, but that should still work, since 3" drains are the norm too. The real trick will be to get the inside diameter of the old pipe to fit around the outside diameter of the new pipe. I have done that with some success by using a 3" pipe with a coupler to act as a filler. The Joint MUST be tight fitting before gluing up or it will leak. DO NOT let the lettering on the sides of the coupler fool you into thinking you have a tight fit, If it even get you close....
    – Jack
    Commented May 8, 2015 at 21:23
  • I just realized there are flanges that fit into the interior diameter of the waste pipe. Pray that it will be tall enough to get your height you need.
    – Jack
    Commented May 8, 2015 at 21:24

You probably wanted something like what's pictured below. It's made for cast iron pipe. You drop it into the old pipe and tighten the internal screws to expand a rubber gasket. This would guarantee a proper seal:

Retrofit closet flange slips into interior of pipe

How you get the required mounting screws to work is up to you. A plumber will have an internal pipe cutter, and she could cut the pipe, remove the old flange and drop one of these bad boys in its place.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.