nomopyt t1_j8nuz4k wrote on February 15, 2023 at 6:07 PM

Reply to comment by lmaccaro in Help with mould in bedroom? by Up_and_ATEM

It's an exterior wall with wallpaper on it. That's acting as a vapor barrier. There may or may not be additional water intrusion, but there doesn't need to be for this to happen. Water is condensing between the wallpaper and the wall bc of poor insulation and temperature differentials from outside to inside, that's my assessment.

lmaccaro t1_j8o898l wrote on February 15, 2023 at 7:33 PM

If so, that would be happening on all similar ext walls with wallpaper.

And would be happening worse closer to the ceiling as it’s hotter up there.

If not, then I think there is more going on. Certainly it warrants closer investigation.

nomopyt t1_j8oca97 wrote on February 15, 2023 at 7:59 PM

No, not necessarily. It matters which cardinal direction each wall faces.

And what you've said about it being more pronounced up near the ceiling does not square with my understanding of the situation. It matters where the air supply diffusers are directed, the position of the doors and windows, and other factors like insulation.

I'm not saying there's definitely no additional water intrusion, but I'm not understanding the reasoning you're using.

Edit: thanks for confirming that the "reasoning" you're using here is... None. Suspicion. Alarmism.