Thanks, completely agree you have to fix the moisture issue. I’ve definitely had plaster repairs fail in this way when leaks persist. I guess my point was that it’s been preferable in my experience to go the plaster route and deal with this rather than the effects of mold growth in the walls. You always “think” you fixed the underlying cause of a leak in an old building, but sometimes it’s less apparent or there are multiple causes. I’m getting PTSD thinking about managing this leased 120 room 1909 San Francisco nightmare.