OK, recently we noticed a wet spot on the ceiling of the garage underneath the upstairs bathroom. I am not sure as to how to fix the problem but have two facters which are possible. The shower is a one piece fiberglass unit and I am wondering whether the fiberglass is flexing around the drain and breaking the silicone seal, the other factor is that we had some shelving on the wall where the pipes are, we recently took the shelving down and than noticed the leak. Is it possible that perhaps one of the screws penetrated the pvc and that the screw was sealing the hole and that it now having been removed is letting the water leak out. Is there a way to fix this problem without tearing out the ceiling as that is not an option at this point. Is there a spray in sealant that can patch holes like in a bicycle tire. Any help or advice on this will be majorly appreciated.
H:confused:

Forget the spray stuff, it's out there but I would not try to use it. You would still need to create an access hole so just do it right from the start. I am going to assume the shelves were in the bath and not the garage. Test you tub idea by filling the tub and then letting the water out. The tub drain would below the floor level of the bath. If it is your problem you will seequite a bit of water. No water? lets go to the wall where the shelf was removed. If you have drywall you can carefully cut and remove a square where your mounting screws were located. Use a drywall saw by hand and plan to reuse the piece your remove. Cut between the studs left to right until you hit each stud. Two cuts, one about a foot or two above the other. Now cut the horizontal cuts to make it look like a rectangle. I am hoping you have just exposed your problem. When reinstalling the piece of dry wall add two stripes of backing wood, I like 1 X 3 s. Screw them into the studs so the front edge is flush with the front edge of the stud. Allow these backers to extend above and below you opening by an inch or two. This insoures the flush mount. Reattach the dryway piece with drywall screws and close with tape and mud. Let me know how this goes and tell me if I helped you.