I live in a condo with another unit above my garage. 6 or more months ago, there was some type of water leak that caused a large section of my garage ceiling to become soaked, sag, and have paint flake off. The HOA sent a plumber to check it, because if it's a leak in the pipes, they're responsible for fixing it. The plumber cut a hole in the ceiling and couldn't detect any cause for the leak. And by the time he came to check it, it was dry. He came back to check it a couple times, but still didn't see anything. The spot is directly under the above unit's toilet. The plumber said that maybe the upstairs flooded their bathroom (they told him they hadn't) or the ceiling had always been that way but the water stains just started to show (it hadn't - the drywall was wet and sagging). I've left the hole open. For several months, I kept nothing under it so I could see if any more water came out. None did, so I figured it was fixed, but I haven't gotten around to replacing the drywall yet. Today as I moved things in the garage, I noticed that the plastic tarps I had below the hole had a lot of water on them, which couldn't come from anywhere but up there. I can see a black plastic ring at the bottom of the toilet that the pipe connects into. That looks like it has moisture around it. (Attached a photo -- tho apparently this site does't recognize orientation data. Left is top in the photo.) I'd rather not have to deal with the any back and forth with the neighbors. (Don't have problems with them. Just don't want the hassle.) Is this something that sounds like it can be fixed without involving them or will it need to be fixed inside their unit?