Leak in upstairs bathroom

[Eurotexan]

Hoping some of you DIYers can give me some advice. My tenant in my townhouse rental called Friday to say there is a wet spot in the downstairs ceiling, right below the upstairs bathroom. I thought at first it might be the wax seal on the toilet, I asked her to turn off the water to the toilet and flush it. She did that, also turned the water off to the sink. No more dripping, yay! Well, she called this morning to say that it started dripped again after her shower (there is another bathroom but doesn't have a shower so she had to use this one).

I know leaks can be misleading, but I have to think it's the shower (well shower in bathtub rather than walk in shower). I am going over tomorrow to take a look but was hoping someone could give me some tips on what to look for. I am slowly but surely getting more into DIY, jobs I used to outsource from the getgo I am now trying to fix myself so I am really learning as I go.

Any advice would be great, thank you!

[Spork]

Leaks can be hard.  Water doesn't seem to always follow logical paths.

The DWV will be hard to prove/disprove without actually tearing out drywall.  You might first look at all the caulk lines around the tub, in the corners and around the shower door (if there is one.)  My walk in shower recently had a leak around the shower door where it leaked along the bottom of the shower door under the bottom frame of the shower door.  From there it leaked at the hinge side where the faux marble jamb hit the faux marble sill.  In other words, the actual leak to the "dry area" was underneath the frame of the shower door.  There was about a 1/4 cup of nasty standing water underneath that bottom frame when I disassembled it.

[James]

Leaks can be hard.  Water doesn't seem to always follow logical paths.

I highly agree, it can be a real pain to find a leak from just a ceiling stain. You seem to be on the right path, shutting off water to see if that helped. But really without seeing the various fixtures involved it's hard to know if it will be difficult or not finding the leak. Sometimes it's obvious, like gaps, cracks, wet pipes under a sink, etc. But other times it just takes ripping drywall out and working from below. Best of luck finding it!

[lthenderson]

Make sure you check the obvious that there aren't any cracks in the bottom of the tub. I've seen them crack before and leak. The next obvious place down the list would to be sure that water isn't getting past the door/curtain to the outside of the tub and then leaking through the interface between the floor and tub/walls.  Assuming a two piece unit, also check the caulking between the tub and shower intersection. Also check the caulking around the shower handles and tub stop areas to make sure water isn't running down the wall and through the holes there. If you rule those out, I would start by tearing out the drywall where it is wet and seeing if you can see where the water if coming from. Otherwise, you may have to tear the drywall out on the backside of the shower wet wall to see if the leak is coming from a rusted out shower valve, etc.