I called the building inspector when I lived in Brooklyn and got tired of the dripping celing in my top-floor apartment. Where was the leak? In the bathroom, and conveniently, it dripped right into the toilet. Downside--it dripped on your head when you were on the pot! I finally rigged a large trash bag, some duct tape and a tube of sorts out of Saran Wrap that ran from the snipped bottom corner of the bag to the sink. Looked like a gigantic udder with a milking machine hose attached. The building inspector thought it was pretty nifty. Apartment owner wasn't thrilled with any of it, because he could never find the leak and had to do the whole roof.

SRS