I just recently bought a house that had a leak in the roof at one time. The leaks made its way down to a bedroom and caused a little sag in a 4x4ft section of the ceiling. My thought was that I could cut out the sag and replace the sheetrock in that section. Once I got in there I found that there was plaster above the sheetrock. My question. Will I still be able to replace just that section or will the entire room's ceiling need to be replaced? Any thoughts on where to go from here?
I would take down the plaster where the ceiling was sagging to get it out of your way. Fir out the structure for the patch so you can match it up with the existing ceiling. Screw or nail it in place. Tape and mud the seams and you should be good to go.