After shower about 3 to 5 minutes, I could hear water dripping (getting loud lately - so I stopped using that shower) downstairs where the vent (kitchen) is. The question is.. Where would the leak come from? 1. Would the shower valve (washer, cartridge) go bad and leak down ? (by the way, I re-grouted wall tiles, caulked them, and I did try to cover every single part of the tiles on the shower, so I am 100% it is not the wall) I currently have moen, can I change to different valve if that is the case? (There is no visible leak outside, but only hearing dripping inside the wall) 2 Can I open up the plate (round one) without shutting off the main water line - Of course, I asked this because I just don't want to touch the water line and I won't turn on the water as well, just want to know if leak can be seen or detected by just opening up the plate. 3. If I have to hire a plumber, is it considered a big job, open up the wall and check the pipes.. how much will it cost me?! Would Plumber normally do the jobs of closing the walls or do I need separate people to do do the job. Is it costly? That leads to the next question, if I have it remodeled, would people check for the leak before installing new shower?