Had a similar issue myself, but it wasn't plumbing-related at all. Turned out to be condensation from poor ventilation in the attic space above. I chased phantom leaks for months, cutting holes and checking pipes... nothing. Finally realized the insulation was packed too tight, trapping moisture against the drywall. Once I improved airflow up there, problem solved. So yeah, paint won't fix everything—but sometimes it's not always a hidden leak either.
"Finally realized the insulation was packed too tight, trapping moisture against the drywall."
That's interesting, hadn't thought about insulation causing moisture issues like that. I had a similar mystery leak in my basement ceiling, drove me crazy thinking it was plumbing. Turned out it was rainwater sneaking in through a tiny crack around the chimney flashing. Took forever to track down. Makes me wonder now if attic ventilation could also affect moisture problems lower down in the house...?
Attic ventilation can definitely play a role. Had moisture issues myself until I added soffit vents and a ridge vent—made a noticeable difference. Proper airflow helps keep humidity down, preventing condensation buildup that can trickle down into lower areas. Worth checking out if you haven't already.
Ventilation definitely helps, but sometimes it's tricky figuring out if you're dealing with old stains or fresh leaks. Had a customer once who kept repainting the ceiling, convinced the roof was still leaking. Turned out, the stains were old, just bleeding through the paint. If you're unsure, try marking the edges of the stain lightly with pencil and see if it expands after heavy rain. Simple trick, but saved us from chasing ghosts more than once...
Had a similar issue once, drove me crazy for weeks. Turns out the stain was ancient, but kept bleeding through fresh paint layers. Pencil trick is solid, but another thing that helped was using a stain-blocking primer like Kilz before repainting. Regular paint just won't cut it sometimes... learned that the hard way after repainting the same spot three times in a month. Live and learn, right?
