I had a plaster ceiling collasped in a 2nd floor apartment building. The roof is not leaking and the foundation is solid. Is it possable that the plaster that is 2-4" thick has pulled away from the nails that are in the studs due to the wieght. The size of the room is 12 x 12. I will be replacing this ceilings with 1/2 drywall and perhaps cover all plaster ceiling with 1/4 drywall with 2 1/2 " screws, hopefully this will prevent a future collaspe. Is this the correct way in repairing this. Any help in this matter, I would greatly appreciated.