I’m looking to renovate a basement bathroom. First time for all of it.

Currently there is a shower panel installed on the wall that I’d like to throw away. I’ve bought 5/8 compression caps (just the cap, no ring) and put it on the water pipes. Turning the water back on I had water sprays out of both caps.

Do I simply need a washer in the compression cap or am I using the wrong thing to try to cap the pipes?

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  • Hello, and welcome to Stack Exchange. Is this picture showing the capped lines, or something else? Apr 5, 2018 at 1:17
  • Hi, thanks for responding. It shows the shower panel (still connected with the water lines) dangling off the wall. The pipes I’m looking to cap are protruding out of the wall. Apr 5, 2018 at 1:19
  • Did you use Teflon tape, or anything on the threads? Did you tighten by hand or by wrench?
    – Tyson
    Apr 5, 2018 at 1:25
  • AFIK compression fittings will not seal on threaded galvanized pipe. Could you not get galvanized caps? Put these on with pipe dope or teflon tape. Apr 5, 2018 at 2:52
  • Thanks, Jim! I went to a different plumbing store today and found properly fitting galvanized caps. With Teflon it did not leak. Apr 6, 2018 at 2:55

1 Answer 1


There should be a washer in the compression cap. You can try to wrap thread tape on the threads first or pipe dope. You can also purchase threaded shut off valves and thread them on the pipes with either pipe dope or thread tape.

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