telling apart fresh leaks from old ones is driving me nuts

Painter's tape is definitely safer—learned that the hard way too. For darker ceilings, I've found shining a flashlight at an angle helps spot subtle changes. Shadows and reflections can reveal a lot more than overhead lighting alone...worth a shot if you're unsure.

"Shadows and reflections can reveal a lot more than overhead lighting alone...worth a shot if you're unsure."

Good tip about the flashlight—I never thought of that. I've been squinting at my ceiling for days trying to figure out if I'm dealing with new leaks or just old stains playing tricks on me. Painter's tape saved my paint job last year, so I second that advice 100%. Glad I'm not the only one going nuts over this stuff...