The shower drain in my first-floor bathroom leaks. Based on looking from the basement below, it seems the leak is at the point where the drain assembly should clamp to the shower base (which is pre-formed fiberglass/plastic). This is confirmed by the ability to wiggle the drain assembly a bit relative to the shower base, and by the fact that the pieces of putty that remain seem to be coming loose from on top.

So to fix this I'd like to loosen the drain from the shower base, insert new putty, and re-tighten.

Here are the views from above and below:

Looking down from shower

View up from basement

I think that what I need to do is loosen the large hex nut visible from the bottom. If I understand correctly, this should loosen the drain from the shower base, and possibly also loosen the compression fitting of the drain around the PVC drain pipe.

Unfortunately, I don't seem to be able to get the nut to budge! Because it is only reachable through the hole in the subfloor, I can't really get a normal wrench around it. Trying to move it with my hands or with screwdrivers inserted into the slots in the nut doesn't seem to work either. Maybe the nut was made harder to move by use of PVC cement, or the spray foam that used to fill this area.

So, how can I move this nut so I can reseal the drain?

  • Is there anything in the drain you can grab on to and twist? The nut may be fixed and the drain could be screwed into it instead. You've got the right idea though!
    – Steven
    Commented Jul 1, 2012 at 15:46
  • I was hoping there would be something I could grab onto and twist from above, but it looks perfectly 360-degree symmetrical. Commented Jul 1, 2012 at 16:16
  • If you can't budge it at all it may have gotten glued shut. On the plus side it's PVC, so reinstalling a new one may not be a huge pain. Commented Jul 2, 2012 at 18:02
  • So if I just have to reinstall, would that mean cutting the PVC drain pipe below, prying this drain assembly apart in order to free it, and then installing a new drain plus a new length of PVC (coupled to the existing PVC drain)? Commented Jul 2, 2012 at 20:39
  • 1
    Basically, yeah. Commented Jul 3, 2012 at 18:17

3 Answers 3


Don't bother trying remove the drain. Don't try to renew the putty, you'll just have the same problem again.

Remove all the old putty you can. Roughen the surfaces that contacted the putty with coarse sandpaper. Clean the shower base and drain surfaces where the putty was a well as you can. Fill the resulting gap with self-leveling polyurethane sealant. Do so in a way to not trap air and to fully fill the void. Once that stuff cures, it'll never leak again!

If you do have to remove the drain in the future, simply cut thru the sealant with a sharp knife.

  • This sounds like a good approach. Will the polyurethane sealant hold even with some motion of the shower based (as people stand on it)? Commented Jul 7, 2012 at 16:57
  • Also, is this the same type of polyurethane sealant used for filling cracks in concrete? I have some leftover Sikaflex SL sealant (homedepot.com/h_d1/N-5yc1v/R-202527281/h_d2/…), could I reuse that? Commented Jul 7, 2012 at 17:00
  • Yes, it handles motion much better than putty. Yep, same stuff, if the leftover hasn't set up, it should still be usable. While it's meant for concrete, you may have noticed it adheres to anything, and once cured, it's there forever.
    – bcworkz
    Commented Jul 7, 2012 at 21:50
  • 3
    Update: success! The self-leveling sealant went in pretty easily after I cleared out the putty with a putty knife. I let it dry for a couple of days. No more leaks! Commented Jul 16, 2012 at 10:34

Sawzall is your friend.

Depending on how comfortable you are with plumbing, using a Sawzall with a fine-toothed blade and some steady hands should allow you to cut the nut on either side and then bust it off with a chisel and hammer.

This obviously implies destruction of the drain; so it will have to be replaced. The primary bit to preserve is the shower enclosure itself.

  • 2
    I would suggest a Dremel with a cutoff wheel instead since you can finely control it to avoid damaging any other components
    – Steven
    Commented Jul 7, 2012 at 2:46

This video was very helpful to me, because starting at 1:13 is shows the instructions for removing an old shower-drain from a pre-formed shower using a hand saw.


(The rest of the video is an advertisement for a drain designed for pre-formed shower-pans.)

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.