I recently had a new roommate move in and his kids are staying with us as well. I live in a townhouse that is less than 6 years old and has never had a problem stemming from the bathroom that they are using. Today, I noticed in my downstairs kitchen, that there was a leak of some sort and has damaged the kitchen ceiling. Upon inspection, I went up to the room and noticed that the floor next to the shower seemed a little damp, but also the closet carpet on the other side of the wall is also damp. I had a different tenant living here less than a month ago, and the shower has been used numerous times over the 4 years I have owned the place. I insisted that one of his children either overflowed the tub or the toilet. I have spoken to old roommates and they have used the shower nonstop in the last 2 months for over 45 minutes and never have had this problem. He insists that because the base of the shower head wiggles a little and there are small cracks in the caulking that this is the cause, and the cause of this is the piping behind the wall. I feel this is insane being the home is less than 6 years old and built of solid construction and passed inspections 4 years ago. If anyone has any suggestions, guesses, or has seen an instance like this before, please let me know. Thanks!!

Also, the downstairs leak is directly above the floor next to the shower and not the shower itself. Any help would be greatly appreciated.

First you can never be absolutely sure of what people do in the shower unless you are there to observe. You can never be certain exactly when a leak begins. Where you see the signs of a leak is only an indicator of the general vicinity of the leak. Water can run a long way before you see the signs. You never know where the leak is occurring until you find and fix it.

Could be that someone is not closing the shower curtain or door completely. Could be that that a leak has begun in the wall where the shower arm screw in the fitting of the pipe that goes up from the valve. Could be the shower valve has started leaking . Could be something else.

If you have an access panel on the other side of the shower wall, open and look for signs of water.

If you don't have access panel, pull the escutcheon ring around the shower arm away from the wall. With flashlight look inside the wall for signs of leak. If the hole around the shower arm is not large enough to see in, you can enlarge it slightly. The escutcheon ring will cover a fairly large opening. If you don't see any signs of water in the wall at the shower head, remove the handles and trim work and look inside the wall for signs of water in the wall around the shower valve.

Post back with what you find.