What could be causing this leak on drywall?

[nxanthos]

I've got quite the puzzle on my hands! I'm no plumber, but I've asked for advice from various professionals and still no sure answer... I'm turning here for help.

When the shower is turned on, whether hot or cold, water appears at a particular spot on the drywall. I've included photos. You'll notice I've captured the moisture mid-accumulation, as it darkens the wall from top to bottom almost every time.

I've considered a variety of possibilities:

(1) Could it be the caulking? It is noticeably thicker on that side of the tub, but it is never wet. Could water be traveling behind the caulking? Is it, perhaps, the wrong kind of caulking? It looks like a DIY job.
(2) I cleaned the vent, thinking it was condensation causing the problem. At first, I was convinced I'd solved the problem. The vent was incredibly dirty and there was far less humidity while taking a hot shower. Furthermore, monitoring the area, I didn't see any dampening. Unfortunately, today I ran a cold shower, just to test it, and water began to accumulate.
(3) Could there be a pinhole leak behind the wall?
(4) Is the shower head spraying horizontally a little onto that side of the wall? I'm going to test this possibility next by placing the shower head on the floor while running the water and seeing if water accumulates in that patch.

EDIT: A few other points of interest: (1) The hot and cold handles require quite the turn to fully shut off, otherwise there is a drip from the shower head. (2) It seems, looking at the kitchen ceiling, that there has been a repair in the past, but that portion of ceiling is not wet and has not changed since moving in.

Thanks for your suggestions.

 

[Geofd]

My guess is condensation, is that sheet rock or(green) board if it's sheet rock it's not meant for damp/wet areas
I just redid my bathroom because of a pipe leak, but before that the ceiling was stained by the shower, I used green board for the walls and ceiling

 

[nxanthos]

How can I tell if it's sheet rock or green board? I mean, it's not green, if that answers the question...

As for the condensation theory: The moisture even accumulates when the water is running cold. Is condensation still a possibility with cold water running?

 

[johnjh2o]

My guess would be that it's the shower arm. The threads on the shower arms are known to fail.

 

[nxanthos]

My guess would be that it's the shower arm. The threads on the shower arms are known to fail.

If the thread has failed, then the water is spurting inside the wall and spreading across to the drywall. Does that make sense? It seems like quite a distance to travel, making me think the damage would be fairly extensive inside.

 

[Geofd]

Look closely at the chrome escutcheon against the wall were the shower arm comes out,can you move the shower arm easily might also be splashing off the body and landing on that ledge put a level on that wall see if it's pitching towards the wall

 

[nxanthos]

Look closely at the chrome escutcheon against the wall were the shower arm comes out,can you move the shower arm easily might also be splashing off the body and landing on that ledge put a level on that wall see if it's pitching towards the wall

The chrome eschutcheon appears to have been caulked over almost completely. Difficult to move the arm. I'll try placing the shower head on the tub floor, where water cannot reach the side, and see if the wetness still occurs.

 

[Rickyman]

Take the shower head off and put a 1/2” cap on the shower arm. Turn on the water to pressurize the riser and arm. If there’s no change to the drywall after 15 minutes you don’t have a leak in the wall

 

[MicEd69]

It looks to me that the water is wetting the surface of the wall rather than soaking through the wall, but it's hard to tell from just a picture. If it is from a surface wetting, then it is likely that all that is happening is water is leaking or splashing onto the shower enclosure ledge and running over to the wall. As there are wall studs between the shower riser and valve, I doubt if any leak from those would be able to spray over to that section of wall.

But is this bathroom in the basement or first floor of a two-story house? Plumbing isn't usually run in an attic space in cold climates or in houses with a basement. So, the ceiling patch may have been for some other reason. But if this is in the basement or on the first floor of a two-story house, the piping could have been run in the ceiling. If the attic isn't above the shower ceiling, and if the patch is close to the wall being wetted, then it may be possible that there is a leak from a pipe in the ceiling.

But check the most likely thing first. Maybe tape a cloth rag rolled up on that ledge and form a dam to see if that stops the wall from getting wet.

 

[nxanthos]

Take the shower head off and put a 1/2” cap on the shower arm. Turn on the water to pressurize the riser and arm. If there’s no change to the drywall after 15 minutes you don’t have a leak in the wall

My apologies for the obvious question, but if I place a cap on the arm, would this plug up the water and cause a problem? Surely the water is meant to escape somewhere?

 

[johnjh2o]

You joined this forum for advice. Instead of second-guessing everyone why not try something?

 

[nxanthos]

You joined this forum for advice. Instead of second-guessing everyone why not try something?

Hey John, I really appreciate all this advice. Didn't mean for my comments to come across as second-guessing, am just trying to understand the thought process behind some suggestions, so that I'm not trying things ignorantly.

 

[MicEd69]

My apologies for the obvious question, but if I place a cap on the arm, would this plug up the water and cause a problem? Surely the water is meant to escape somewhere?

I'm assuming you are seriously asking this question, so please just think about what you asked.

There are multiple valves in your water lines. You close them and the water stops and doesn't "escape somewhere". So, putting a cap on the end of a shower arm is just like another valve in a line that already has multiple valves. There is a solid pipe between that valve and the shower arm, so where would the water "escape".

Not to be sarcastic, but to add a little humor, your question reminds of an "All In The Family" episode where Edith is having some plumbing work done. The plumber said that when he was a little boy, he always wondered how the water knew whether to go to the kitchen or the bathroom. Edith laughed, and then asked, "How does it?"

 

[brad0102]

i go with your possible option #3....small pin hole leak behind the drywall. i've seen, more than once that the 90 degree piece (called a shower head ear drop) that the shower diverter/riser pipe is soldered to has a hairline crack where the shower head neck screws into. flexing occurs at this point when the shower head gets moved for adjustment or the shower neck was tightened a bit too much into it ......true sign would be some mold on the backside of the drywall....green board(which is is supposed to be) or not. also, after opening up the wall to correct the situation, some faint "cobwebbing" will probably be evident in that area indication faint traces of moisture in the wall cavity.....i had the beginning of some paint chipping on the drywall not too far from the shower neck......riser pipe was in an open wall cavity, secured to some blocking in the enpty wall cavity...interior wall with no sound deadening insulation....riser pipe sectioned and new ear drop installed...fixed.

 

[Twowaxhack]

I'm assuming you are seriously asking this question, so please just think about what you asked.

There are multiple valves in your water lines. You close them and the water stops and doesn't "escape somewhere". So, putting a cap on the end of a shower arm is just like another valve in a line that already has multiple valves. There is a solid pipe between that valve and the shower arm, so where would the water "escape".

Not to be sarcastic, but to add a little humor, your question reminds of an "All In The Family" episode where Edith is having some plumbing work done. The plumber said that when he was a little boy, he always wondered how the water knew whether to go to the kitchen or the bathroom. Edith laughed, and then asked, "How does it?"

I had a lady dentist ask me how the water know how to go back to the water heater after you quit using hot water.

She also asked where does the water come from tyst fills the toilet, does it have its own line from the street