Leaking Shower Arm

[mjc1234]

Hi all - installing a new hand held shower head. I'm getting a leak where the shower arm extension screws into the water line that is inside the wall. I've done the following:

1) Used thread lock
2) Used thread lock with thread tape
3) Used a different thread lock

I've tightened it as far as possible (in fact I think I may have overtightened it) and it still leaks. Not sure what else to do at this point. I do have access from behind since I haven't hung drywall on the backside of the wall yet.

Any ideas would be appreciated at this point.

Thanks,

Mike

 

[glennjanie]

Hello MJC:
If you are screwing the shower arm into a female fitting that is plastic (CPVC), you may have split the fitting.
In my world, the joint compound is only a lubricant to help you screw the male into the female far enough to get a water/air tight seal. In spite of what the can says, it can't prevent leaks on its own. The threds in the female fitting should close in as you go deeper into it; likewise, the threads on the male pipe should go from a smaller diameter to larger as it is screwed into the female. This causes the pipes to 'wedge' together for a tight fit; the joint compound and tapes are only to lubricate the mating surfaces so you can get the wedge tight enough.
I would try a new Ell and use teflon tape.
Glenn

 

[majakdragon]

I totally agree with Glennjanie. Pipe threads are tapered. Place a pipe nipple on a flat surface and you can see it. Pipe dope compounds are a lubricant, not a leak stopper. Plastic female fittings are prone to cracking. Many areas do not allow them in confined areas such as inside walls. If you still have access, look and see where the water is leaking from. Bet it is the elbow and not the actual threads.

 

[frodo]

there is a term i use in the plumbing trade it is ''gorilla tight''
a lot of people think that a plumbing pipe has to be ''gorilla tight''
it does not. your are screwing a niple in to a fitting that will have no pressure on it. the water will just pass thru it. also you will have to unscrew it one day. to put on another head. it sounds like you cracked the fitting inside the wall.cut the wall out ,behind the shower. it will be easier to patch that way