Horsehair Plaster Question - Mold?
This is my first century home, a modest but overpriced 1920s farmhouse in New England with ample horsehair plater walls. Most of it is in pretty good shape, but I found some large cracks in a bedroom closet that had obvious attempts at lazy repair plastering before I came along. The two walls with the most cracks abut the exterior.
Since this is a closet and I'm lazy too, I set about putting up some spackle and calling it a day. Attempting a sanding after that led to crumbling of the surface around some of the bigger cracks. These sections of plaster have clearly detached a bit from the lathe. I've already ordered some plaster washers, mesh tape, and construction adhesive, but was a little concerned by a subtle darker color difference in the underlying plaster (left side of the exposed chunk) that I thought could indicate the presence of mold, and potentially be the cause of the detachment here. Pictures go from broader to closer.
While we've had a rough winter for snow, ice dams, and rain, this area did not seem to be damp at all at the interior - as far as I've noticed. Do you think it's okay to do a standard minor drywall repair, versus exploratory tearing-out to check more thoroughly for mold? Am I being paranoid?