I just finished repairs for a shower stem that broke behind the wall and leaked down into our kitchen.
Upon inspection, it looked like the pipe finally gave out after flexing with the hot/cold water. As it flexed, it was pushing against the hole in the wall (the tile and drywall) because the copper pipe from the valve was just a smidge too long. Eventually (30 years) of metal fatigue finally broke it off completely, but you could see that it had been leaking for some time - just not enough to 'notice' until it finally completely separated.
So make sure to take a good look at where the shower stem connects to the pipe behind the wall.
DrewTea t1_j6yty23 wrote
Reply to Help Diagnosing Shower Leak by Rolltide2014
I just finished repairs for a shower stem that broke behind the wall and leaked down into our kitchen.
Upon inspection, it looked like the pipe finally gave out after flexing with the hot/cold water. As it flexed, it was pushing against the hole in the wall (the tile and drywall) because the copper pipe from the valve was just a smidge too long. Eventually (30 years) of metal fatigue finally broke it off completely, but you could see that it had been leaking for some time - just not enough to 'notice' until it finally completely separated.
So make sure to take a good look at where the shower stem connects to the pipe behind the wall.