The Historic District

The Pacific Northwest is known for its damp rainy climate and the exfoliation of material seen in the photos is consistent with dampness migrating through the wall to the paint layer weakening its bond until it detaches. I can see at least three different paint layers and while that number of layers...

Newbie here to Wavyglass but veteran old house restorer/owner. Nettie's advice is sound. You can also access the ceiling via the attic side assuming you have access to one and see what appears above that room if its on a second floor. (although the attic too may have flooring covering the ceilings u...