How to Fix a Shower Leak Behind the Wall – Part 2

How to Fix a Shower Leak Behind the Wall: Trace the leak to the shower arm and elbow connection, remove the arm, clean and wrap the threads with plumber’s tape, then reinstall the shower arm.

This project is continued from How to Fix a Shower Leak Behind the Wall.

Shower Arm and Elbow Connection is Leaking

I reattached the shower head then turned on the shower. The shower leak was plainly seen. The leak was coming from the threaded joint at the shower arm and the drop ear elbow:

Shower Leak behind the Wall Repair: Shower Arm and Elbow Joint Leaking

Shower Leak behind the Wall Repair: Shower Arm and Elbow Joint Leaking

I unscrewed the shower arm from the elbow and observed that:

  • The shower arm was threaded-in very tightly – this is good.
  • The threads were sealed with pipe joint compound – also good.
  • The pipe joint compound had become brittle and dry, this caused the shower leak.

The shower arm is pictured below. The pipe joint compound is the white stuff in pipe threads:

Shower Arm Leak Repair: Old and Brittle Pipe Joint Compound

Shower Arm Leak Repair: Old and Brittle Pipe Joint Compound

Shower Arm Leak Repair

A brass-bristle wire brush was used to clean the old pipe joint compound from the threads of the shower arm. Brass is a soft metal and won’t scratch the nickel finish. The shower arm was polished with a cotton cloth.

Fix a Shower Leak: Shower Arm after Cleaning the Threads

Fix a Shower Leak: Shower Arm after Cleaning the Threads

The shower arm threads are sealed with Teflon plumber’s tape. Wrap the tape clockwise (with the pipe end facing you) so the tape won’t unwrap as the shower arm is threaded into the drop ear elbow inside the wall:

Shower Leak Repair: Wrap the Shower Arm Threads with Teflon Plumbers Tape

Shower Leak Repair: Wrap the Shower Arm Threads with Teflon Plumbers Tape

The shower arm threads wrapped after Teflon plumber’s tape is shown in the following photo. I prefer Teflon tape for this job over pipe joint compound because I wouldn’t be able to get a wrench on the elbow to really tighten the joint and I felt that Teflon tape does a better job of sealing gaps in the pipe threads.

Show Leak Repair: Shower Arm Threads Wrapped in Teflon Tape

Show Leak Repair: Shower Arm Threads Wrapped in Teflon Tape

The old pipe joint compound was cleaned from the drop ear elbow with the brass wire brush before reattaching the shower arm:

Drop Ear Elbow for the Shower Arm

Drop Ear Elbow for the Shower Arm

The shower arm was threaded into the drop ear elbow inside the wall and the shower head reattached. Then the shower is turned on to watch the plumbing joint for leaks. No leaks! Problem solved!

Shower Leak inside the Wall Repair: Check the Shower Arm for Leaks

Shower Leak inside the Wall Repair: Check the Shower Arm for Leaks

Install a Shower Plumbing Drywall Access Panel

The ugly inspection opening in the drywall was covered by 12 inch by 12 inch white return grill purchased from Lowes. The grill can be easily removed for maintenance or repair if needed in the future.

Drywall Plumbing Access Panel: White Return Air Grill

Drywall Plumbing Access Panel: White Return Air Grill

Here’s a better perspective of the bathtub/shower and wet wall with the newly installed white grill.

Shower Leak behind the Drywall Repair: Wet Wall and Bathroom

Shower Leak behind the Drywall Repair: Wet Wall and Bathroom

Update: bauco softline Access Panels

I was later introduced to the bauco softline access panels and replaced the air return grill for a better and more professional solution.

bauco softline Access Panel: Shower Plumbing Drywall Installation

bauco softline Access Panel: Shower Plumbing Drywall Installation

The final task is to paint the downstairs closet ceiling to cover the water stain.

Thanks for reading,

Bob Jackson

Copyright © 2016   Reproduction strictly prohibited.

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30 Responses to How to Fix a Shower Leak Behind the Wall – Part 2

  1. Susan Carroll July 18, 2010 at 11:51 am #

    Thanks for the great tips and photos!

  2. budsmamma June 3, 2011 at 12:05 am #

    What do you do if the threaded joint at the shower arm and the drop ear elbow are rusted?

    • Bob Jackson June 3, 2011 at 4:30 am #

      Take a bath. :-)

      Remove the shower arm and clean the drop ear elbow threads with a small wire brush and blow clean with compressed air. Is the rust mainly cosmetic or are the threads heavily corroded and about to fail? If the drop ear elbow interior threads are still in OK condition, coat the threads with pipe joint compound and install a new shower arm.

      Otherwise, you’ll have to replace the drop ear elbow. That could be a major task if there’s no access panel and you have to tear open the wall.

  3. Betty February 13, 2012 at 1:10 am #

    Thanks for the really good instruction and pictures – will give it a try tomorrow!

    • Judy September 20, 2015 at 1:10 pm #

      This has nothing to do wth what I’m going to ask….the plumber fix the leak but our homeowners is to repair the drywall. The hole has been open for a month right at our tub.
      Can this cause mold in the wall if not closed soon. Please email me. I would so much appreciate an answer Judy.

      • Bob Jackson September 20, 2015 at 1:54 pm #

        It won’t cause mold and should aid the drying out process by exposing the wall cavity to the air.

  4. meddian April 5, 2013 at 2:04 pm #

    Hi Bob,

    This was the best explanation I have ever read! My son was upstairs taking a shower and I was below and felt drip, drip. I knew it was coming from the shower above. I’m having a waterline guy coming to inspect Sunday. There is so much water-mine might not be the shower arm it might be the water line we will see. Thank you!

  5. Tito Calo September 10, 2014 at 9:06 pm #

    I changed the shower head arm with a new used teflon tape put it back on and still have a leak behind the shower wall , could I have done something wrong?

    • Bob Jackson September 11, 2014 at 7:13 pm #

      Maybe. Are you certain the shower arm threaded connection to the drop ear elbow was leaking? Can you see the leak now?

      If so, remove the shower arm, clean the threads on both the shower arm and inside the drop ear elbow. Check the shower arm for damaged threads, mineral deposits, etc. In fact, you might just buy a new shower arm at the home improvement store – it’s inexpensive about $10. Rewrap the shower arm threads with plumber’s tape and install it. Check for leaks and try tightening the shower arm one full turn if it’s still leaking.


  6. Candy May 3, 2015 at 2:18 am #

    Shower (2 sided glass with a door style) leaking onto bathroom floor? I reapplied caulk around base of shower inside, no change or maybe made it worse? How do I figure out where the leak is coming from? Please help. Thanks.

    • Bob Jackson May 4, 2015 at 12:48 pm #

      To check if the shower pan is leaking:
      1. Towel dry the shower pan.
      2. Remove the shower drain strainer.
      3. Install an inflatable drain test plug. Inflate the rubber test plug with a bicycle tire pump.
      4. Measure 1 inch above the shower pan and place a 3 inch piece of duct tape on the curb above the 1 inch mark. This is your fill line.
      5. Fill a bucket with water from the kitchen or laundry sink and pour it in the shower pan until the water level meets the bottom of the duct tape fill line. DO NOT operate the shower when filling the bucket in case there’s a shower plumbing leak.
      6. When the shower pan is filled with 1 inch of water, look for leaks around the base of the shower. 30 minutes should be sufficient.

      If you see a leak deflate & remove the drain plug to empty the water. You now know there’s a leak in the shower or possibly the shower drain. Tracing the leak source will depend on your shower pan construction – is it tiled or fiberglass? If fiberglass is the curb molded into the pan or as it appears with your shower separate pieces glued & caulked in place.

      You can e-mail photos to bob[at] replace the [at] with the @ symbol.


  7. Dave June 13, 2015 at 12:28 am #

    Hi Bob,
    I am changing shower heads. For one I am adding an extension to adjust the hight of the head. the old hand held shower head leaked at the head / arm connection. The arm is tight to hand & is facing downward- normal. When I attached the extension set up I turned to wrench tight. now the extension arm is lop-sided-
    not in proper alignment. Do I take the extension arm off the arm & put lots+ of teflon tape on it so that it snugs up hand tight & properly in-line?
    The other project is a tub & changing a normal shower head to a handheld. When I removed it, the arm was loose & tightened hand tight to a 9 o’clock position. Do I remove it, clean & rewrap with lots+ teflon tape applied clockwise & clean the drop ear elbow & reattach the arm to snug hand tight & aligned? Do you think it may have been so loose that it leaked? there is no evidence of same.
    Thanks a lot for all your help.

    • Bob Jackson June 13, 2015 at 10:02 am #

      Shower arm extension: Yes – I would wrap a few extra layers of tape around the shower arm extension so it doesn’t drip when aligned but not completely tight. The good news is any drips will fall to the shower floor so it’s only a cosmetic issue. If it’s still not satisfactory try a shower arm extension from a different manufacturer because the thread start o’clock position may be more favorable and/or quality and taper.

      Bathtub shower arm: Best to buy a new arm. The drop ear elbow female threads are tapered. The new arm will get progressively tighter as it’s turned in the elbow and it’s not necessary to over tighten it. Wrap 4 or 5 turns of plumber’s tape around the arm threads, turn it hand-tight (snug) into the elbow, then no more than 1/2 to 1 extra turns – you should feel a rapid increase in resistance at this point – until it’s properly oriented. The tapered threads and tape will make a water tight seal. Wait 15 mins and check for leaks.

  8. Frank G. June 19, 2015 at 1:48 am #

    Hi Bob,
    Your site here is a godsend. I read with interest the 2nd part of this column, as I seem to have that exact problem: shower arm leaking(I think). Maybe at the same place as pictured in your post. We noticed the shower was leaking behind the main floor shower wall – from dripping down under it in the basement and from the fact that you can see water leaking out also from behind the trim plate in the shower stall itself.
    So from your column I am guessing I have to remove the shower arm and inspect it and possibly replace it(hopefully that is all, anyway). I was just wondering if there was a certain tool which would be helpful in removing it, and this may seem a stupid question, but also which way to turn it… the usual left-to-loosen and right-to-tighten? I know some pipes can be differently threaded, that’s why I ask that.

    Thank you immensely for any help you can give!

    • Bob Jackson June 19, 2015 at 11:17 am #

      No tools are needed to remove and install the shower arm. A wrench would mar the finished, too.

      Grasp the shower arm with both hands – one at the base and the other past the bend; the bend provides enough off-center leverage to turn the arm. The shower arm has a standard right-hand thread: lefty-loosey (counter clockwise) and righty-tighty (clockwise).

      • Frank G. June 19, 2015 at 3:25 pm #

        Ok, I will try that, thanks again!

  9. Toni November 30, 2015 at 12:36 am #


    This is the best article I could find describing my problem. :) But, I’ve noticed the drywall at the top of my fiberglass shower wall is showing water stains, almost all the way around the wall. It seems to be getting higher and higher. I was trying to avoid having to take the whole shower and tub out. It is one big piece. Could it be the shower head leak you are talking about above? I’m a single mom, so I can’t really afford a plumber, so any help would be greatly appreciated! I can send pictures if you need me to. Thanks!

    • Bob Jackson November 30, 2015 at 8:43 pm #

      Is the shower head mounted on the drywall above the top of the fiberglass shower stall? I’m thinking it’s cause by one of two things:

      1. Water is dripping from the shower head or arm onto the top of the shower stall and running horizontally around the wall.

      – or more likely –

      2. Heavy condensation on the drywall from a steamy shower is dripping down the wall, pooling on the top rim of the shower stall and soaking into the drywall. From there the water is wicking up the porous drywall via capillary suction.

      If the shower head or arm were leaking per situation #1 it seems unlikely the water would travel around the corners of the shower stall, instead it would spread out several inches left & right below the shower head before running down the side of the stall.

      For situation #2 the warm moist air from the shower can condense on the cooler drywall above the shower stall and wick down evenly on all sides to the top rim of the stall. Take a close look at the drywall before and after a shower. Do you see beads and streams of condensate? If the caulk seal between the fiberglass stall and drywall is missing or deteriorated, the condensate water will eventually soak through the drywall and wick upward creating the water stains on all sides. Best get a step ladder and inspect the top rim of the shower stall. Is the caulk missing, cracked or the drywall paint peeling? If so the repair is to remove the old caulk and chipped/lifting paint, wait several days for the drywall to thoroughly dry, apply a high quality shower & bath paint, then recaulk the joint with a silicone mildew resistant non-paintable caulk.

      You can e-mail photos to bob[at], replace the [at] with the @ symbol.


  10. John December 9, 2015 at 8:06 pm #


    Your opinion needed, I have a leak somewhere in my shower wall, it will leak when the shower is not being used, so I cant turn the water on in the house. Before I go into the drywall should I replace the shower arm? Your thoughts.

    Thanks, John

    • Bob Jackson December 9, 2015 at 9:57 pm #

      If the shower arm were leaking the leak would stop a short time after the water supply to the house is shutoff or the shower valve closed. The shower arm screws into a drop ear elbow and shouldn’t being holding water. My shower arm only leaked when the arm was pressurized with running water.

      It’s easy enough to remove the shower head and escutcheon (trim plate) to look for a leak. If you don’t see a problem you’ll need to open up the drywall to trace the source.

  11. Sue P December 22, 2015 at 6:28 pm #

    From the helpful descriptions you give, it appears our shower leak may well be coming from the drop ear elbow. However, the leak seems to only occur if the shower head is removed from the holder and is moved around by the person taking the shower. Does this indicate the shower valve may be at fault? Thank you.

    • Bob Jackson December 23, 2015 at 1:07 pm #

      OK – you have a handshower (shower head on a hose). Because the shower only leaks when the head is removed from the holder and moved around, it’s probably caused the shower arm to loosen a bit and leak at the drop ear elbow. The drop ear elbow takes all the stress & load from the shower arm and handshower.

      The drop ear elbow has two plumbing connections: 1) The water supply inlet pipe which is normally a solder joint connection and almost never leaks; 2) the shower arm threaded outlet. The shower arm joint is way more likely to leak.

      Try removing the shower arm, clean the threads, wrap it with plumber’s thread seal tape and reinstall as explained in the project. It’s an easy repair and plumber’s tape only costs a couple of dollars.

  12. Rita January 20, 2016 at 5:17 pm #

    Hi Bob I think this is probably my problem as well. I’ve had a few plumbers over who have tried to do minimal repairs such as one that replaced the cartridge and the most recent one just caulked around my spout. The first one mentioned opening the wall and I agreed to do that but they keep putting it off. This has been going on since March and it’s getting really frustrated. I am to the point that I’d like to do it myself. If it’s not this particular problem, what else could it be and is that something I can try to do myself? Do you have any idea how much it would cost for a plumber to do the job? Thanks!

    • Bob Jackson January 20, 2016 at 6:07 pm #

      “caulked around the spout” is like sweeping dirt under the rug! Try cleaning and reinstalling the shower arm first because it’s a fairly simple and inexpensive task.

      If you’ve not done drywall and plumbing work before then I don’t recommend trying it yourself. It’s too easy to get in over your head and end up calling a plumber after all.

      The best way to get an idea of the cost is to contact three licensed plumbers, explain the problem – persistent hard to find leak, probably need to cut the drywall, install an access panel for future contingencies – and ask for the diagnostic fee. Once the leak is found they can tell you how much it’ll cost to fix it.

  13. Vernon January 21, 2016 at 3:13 pm #

    Hi Bob I have a leak also only when we take showers. We’ve been taking baths to prevent water from leaking into my bedroom. When I pull the knob on the bathtub faucet to shower, the leak happens. Also there is still water coming out of the tub faucet when the shower is on. Major problem or not? I’m gonna start by replacing the shower arm. What do you think?

    • Bob Jackson January 21, 2016 at 8:28 pm #

      > When I pull the knob on the bathtub faucet to shower, the leak happens.
      That’s strong indication the shower arm is probably leaking where it screws into the drop ear elbow.

      > Also there is still water coming out of the tub faucet when the shower is on.
      The flow diverter in the bathtub spout is wearing out and leaking, a common issue that’s unrelated to the leaky shower. When you pull pop-up knob on the tub spout it closes a gate and redirects the water to the shower head. See the Tub Spout Installation Guide by for replacement instructions.

  14. Adrianne August 1, 2016 at 7:57 pm #

    I have a water issue in my shower as well. It happens when I turn on the water knobs in my shower. But the water is leaking from behind the gasket where the knobs are attached and water is falling down the wall into the shower and behind the wall. Please help!

    • Bob Jackson August 1, 2016 at 9:03 pm #

      Your shower has separate hot and cold water knobs, correct? If so, it’s probably a bad bonnet or packing washer on the shower faucet stem. My advice it to call a plumber because you’ll need special wrenches and tools to remove the faucet stem and match it the correct repair parts.

      Shower Faucet Repair (thorough step by step.)
      How to Repair a Leaking Tub Faucet

  15. Sri September 15, 2016 at 3:30 pm #

    I have a similar issue ( I guess). We have a walk in shower with tiled walls. We have occasional leak from this bath room to the dining room in first floor. We have a hand held shower similar to what you have shown and we have splashed water on all the walls and directly on the shower valve and the shower arm but no leak occurs. When we close the shower valve, we notice that a handful of water leaks into our dining room downstairs. Few months back we had got new plumber’s teflon tape put and maybe that is given way and maybe we are having a leak at the same location as what you have shown. Before opening everything, I want to get your opinion. I too don’t have an access window to look at the joints.Please let me have your opinion on possible cause and a solution.

    • Bob Jackson September 15, 2016 at 7:58 pm #

      Hold a bucket under the shower head, fill and empty it in the sink. Repeat until you’ve used 5 gallons of water. It’s important that no water goes down the shower drain.

      Is water leaking on the ceiling?

      * If yes, the leak is in the supply plumbing. Maybe the shower drop-ear elbow & shower arm joint, shower valve or possibly elsewhere due to a bad solder joint. Remove the shower arm and shower valve escutcheons to shine a flashlight and look for drips. Note the shower arm elbow joint will only leak when the shower is running.

      * If no, the shower drain may be the culprit.

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