bathroomleaksplumbingshower
No previous leaks were found, but one morning the kitchen floor (on the other side of the bathroom wall) flooded when the shower was turned on. It's a high-usage shower, used for a minimum of 2-3 showers a day. Suddenly it just started flooding, but the bath is not showing any signs of a leak.
What is the most likely issue? Could it be the pipe above the faucet?
Maybe someone hit a drain pipe when drilling a wall anchor? That it only happens with the water off is odd, I'd just focus on finding the leak. The water is coming from somewhere.
I'd start by opening up any access panels you have to the upstairs shower. You're looking for blackened wood where the pipe enters the floor in the wall.
You're probably going to have to replace the drywall around the ceiling spot, you might as well open that up too. Try to drain the bubble by poking it in case it still has water in it. find the vertical source of the water that way- though occasionally water travels horizontally.
Follow the water. You make enough holes in the wall and you'll find the source.
You have a blockage further down in the pipe that services your shower, toilet and sink. That's creating a sea of liquid that comes out at the lowest available point (i.e. your shower). Drain cleaner will be worse than useless; while a pool of poop may be nasty, a pool of caustic poop would be even worse. A 5' or so drain snake won't do it; you probably need something much longer, and a way to get it into the pipe (past the traps on whichever device you enter through). And, until you've cleared it, stop adding liquid to the situation.
Best Answer
The easiest and first thing to check is the trim pieces around your valve knob(s). These trim pieces usually come with a cheap foam gasket, which crumbles apart after a while. Then water runs down the wall, gets behind the trim, and goes into the wall.
When you take the trim pieces off, if the gaskets look bad, scrape them off and replace them with a bead of plumber's putty, which works much better than foam gaskets and lasts forever. Form the bead all the way around the trim, but leave a little opening at the bottom of the trim; that way, if some water does get behind the trim somehow, it will have a chance to escape, rather than accumulate behind the trim.