I've seen some posts on this subject but haven't been able to find a direct answer to my question so please excuse me if this information exists here already, but...

I just moved into a new home and I have a leak coming form my second floor shower - a one piece fiberglass stall. Prior to purchase, the home inspoection revealed a wet spot in the closet below the bathroom and the previous home owner claims to have repaired a leaky drain in the shower above. Shame on me for not checking into this further.

Now when that shower is used, I can hear water dripping in the area of that closet, and if I go into the basement, water is dripping down one of the supply lines into the basement with some evidence of moisture in the subfloor right around the line (only a couple of inches around it appear to be wet). So, is the leak in the drain, the supply line? Where do I start to determine the source of the leak? Should a cut a whole in the ceiling of that closet and see what I can see?

Thanks for any advice on where to start.

" is the leak in the drain, the supply line? Where do I start to determine the source of the leak? Should a cut a whole in the ceiling of that closet and see what I can see?"

I don't see where you have much choice but to cut a square hole in the ceiling, (save the square. You'll be using it later when you patch back up)
Your shower drain looks like this, (see image) My bet is that the seal on the drain lip got ruptured causing a leak. Loosen the big nut until you can insert plumbers putty or silicon gel all the way around and under the lip. Now retighten the nut and squeeze out the excess. Now try it and see if the leak doesn't disappear. Let me know how you make out. Good luck, Tom

Thanks a bunch, Tom. I probably won't have a chance to get in there for a couple of days, but I'll let you know how I make out once I open it up.

Eric

Hi Tom.

I opened it up last night and I could see water dripping in around the threads on the drain. I poured some water in around the perimeter of the drain - there's in indentation there so I was able to do this without getting any water in the drainpipe itself. The water was actually seeping in underneath the rubber washer that was used as a seal up top in the shower itself. So, I removed that and replaced it with plumbers putty. This seems to have done the trick.

Thanks so much for the diagram and your help.

Eric

"The water was actually seeping in underneath the rubber washer that was used as a seal up top in the shower itself."

The shower drain was installed incorrectly from the git-go. The installation goes like this.
Under the lip of the drain and on top of the base a ring op plumbers putty or silicon caulk. UNDER the base the rubber washer, the fiber anti-friction washer and the latge retaining nut. If you have removed the rubber washer under the lip of the drain and replaced it with a putty seal then you should be OK. Good luck, Tom