Had something similar happen in my attic—spent days chasing what I thought was a roof leak. Turned out moisture was sneaking in through a poorly sealed vent and condensing on the plywood. Worth checking vents and seals too, not just insulation...
Good point about vents, but honestly, I'd slow down before assuming condensation. Condensation usually shows up evenly across surfaces, while actual leaks tend to leave more localized stains or drip marks. Try marking the edges of the stains with pencil and check back after heavy rain—if the stain grows or darkens noticeably, you're probably dealing with an active leak rather than condensation. Saved me from tearing apart my attic insulation once...
"Try marking the edges of the stains with pencil and check back after heavy rain—if the stain grows or darkens noticeably, you're probably dealing with an active leak rather than condensation."
Totally agree with this advice, marking stains is a lifesaver. One extra thing I'd suggest is checking your attic space during or immediately after rain. Grab a flashlight and look closely at rafters, around nails, and along seams in plywood sheathing—fresh leaks often show up as shiny wet spots or darker wood patches. Helped me pinpoint exactly where water was sneaking past my shingles without tearing everything apart...
Good points here, but what about stains on textured ceilings or popcorn finishes? Pencil marks don't show well there...maybe masking tape edges instead, or is there a better way to track those tricky surfaces?
Masking tape might peel paint off popcorn ceilings, happened to me once...not fun. Maybe try painter's tape instead? It's gentler but still visible enough to track. Another thought—could you snap quick pics with your phone periodically and compare them later? I've done that before when I wasn't sure if a stain was growing or just my imagination playing tricks.
Also, speaking of tricky surfaces, how do you handle stains that are faint or blend into darker ceiling colors? Had a leak in a room painted dark gray, and it drove me nuts trying to figure out if it was getting worse or just drying weirdly. Any tips for darker ceilings?
