Black stains on ceiling .
Hi. I have a weird situation happening on my clients upstairs ceilings. There are black stains appearing on the drywall ceiling. Up close it looks like moisture was collecting on the surface because the stucco ceiling was crumbling in certain areas. (See pictures) the stains range from right against the ceiling/wall junction and about 1 foot away from wall. I went up in the attic to check above and found no signs of water stains on top of the drywall. The vapour barrier was in tacked. Insulation is blown- in fibreglass (roughly 18-20” in thickness) but less as the roof slopes towards the soffits. Any help would be appreciated.
House located in Toronto, Ontario. Canada.
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