While working in the attic I fell between the rafters and cracked the plaster ceiling in the room below. The ceiling now sags between the rafters and I want to lift it up level and repair the cracks. Does anyone have a suggestion for raising the ceiling? Thanks for any ideas.

Unless you want to rent some type of long screw jack, cut a couple of 2x4s a bit longer than the ceiling; put a piece of plywood between the 2x4 and ceiling to distribute the force; scoot the bottom of the 2x4 so it approaches vertical. That should hold what is probably sheetrock (not plaster) so that you can secure it to the rafters with drywall screws. You might consider doing the whole room with drywall screws, because older homes used nails to secure the drywall and they can pull out over time. Tape and mud the cracks and screws; texture and paint. I hope this helps.

Thanks for the advise Dr D and that was my first effort, but the sag is between the rafters and the sheetrock screws into the rafters didn't lift the ceiling flush across the sag. I don't have anything at the crack to sink a screw into to lift the sheetrock. Do you have any other ideas?

You could get into the attic space and put one or two 2x4 scabs between the rafters for support. Just don't fall through again. Rather than try to swing a hammer to nail in the confined space, pre-drill a couple of holes throgh the rafters where the scabs will attach, and use longer drywall or decking screws for attachment.

Another point. If the drywall was broken at the sides away from the center crack, material may have moved into the break(s) making it impossible to return it to its original position. You may be forced to cut out a larger section of the ceiling and replace the drywall. Cut it at the center of the rafters so you have something to screw to. Two scabs will probably be needed at the ends of the new piece, centered at the joint of old and new material. I hope that you can avoid this, as it is more work.

Do you have any suggestions as to how to repair peeling in plaster ceilings?

First you need to determine if it is a real plaster ceiling, of sheetrock with a thin coating of mud over it. If it is a sheetrock ceiling, and the home is over 20 years old, they may have used nails instead of screws to attach the drywall. The nails may have allowed the ceiling to sag. If so, it should be carefully rescrewed to the ceiling joists. In any case you will have to remove all the loose material from the ceiling with a wire brush or putty knife. Then some sanding (which gets dust everywhere) to knock down high spots. Then a damp sponge to remove dust from the ceiling so that new material will stick better. Apply drywall mud to fill in imperfections, sand and repeat. Some people use a damp sponge to smooth out high spots on the mud when dry (less dust). Then you can use a texture gun (air compressor required), or apply texture with a wide knife. This whole process is messy and dusty. You may wish to cover floors and door openings with plastic to contain the mess. Good luck.

You should be able to use 2 1/2 screw to lift it up, saying it will go back up again, but it should be fine.

When you use the screws just make sure there going back into the joist. You'll have to then fill all the nail holes and cracks with sheetrock mud, remember to tape those cracks with mesh tape to help hide them and to keep them from showing back up

what's the best way to cut real cement plaster ceiling ? I have a bathroom above me and afraid to use a sawasall for fear of possible plumbing pipes, I have to work upsidedown. Thinking the best secure way is to tap a 1x6 piece a pine and using it as support for vibration as well as a guide for a diamond blade set to debt in a circular saw, what I can't reach with that, I'll use the sawsall with care until I see what's above the plaster cement ?