This is a mystery - leak or condensation?

[frodo]

Sheet rock is easier and cheaper to patch than tile
that said
cut the sheet rock out from behind the plumbing wall
in other words, cut the rock in the room on the other side of the wall from the valve
and take a looky see as to what exactly is leaking

 

[jeffw_00]

Yes - when I look up from below, I see the source of the leak is running down the outside of the tub. I have already tried covering the plumbing wall with plastic to no avail. It's not going through the wall, it's coming from the plumbing....

 

[jeffw_00]

and yes - likely we will have to cut in from the other side - luckily that is behind a door in another bathroom. Plumber comes Friday. I have my sheetrock saw

 

[jeffw_00]

It was the diverter valve leaking

 

[jeffw_00]

so much less of a mystery - plumber was in/out in 20m (But at least I was able to give him a clue)