I'm hoping someone here can give me instructions on how to repair damaged plaster. We had some water damage to a wall under a window from an air conditioner unit we used. We have radiator heat so unfortunately, no central air for us! It seems that the top, veneer like, coat of the plaster is coming off. It is a very thin layer. Underneath that is a concrete like, rough surface that is still intact. If I understand correctly, this is the base coat or brown coat? From what I've been told it's relatively easy to repair this but I'm not sure where exactly to begin other than removing the old plaster off the walls. I would estimate that once we pull all the loose stuff off, it is going to be about 5-10 square foot or so at the most that we need to repair. I figure it can't cost much in materials and why not give it a try ourselves first before calling in the professionals? So, anyone know anything about this? Thanks