What is the best way to finish plywood?

[Tino]

Our master has a suspended (?) plywood ceiling panels. The old paint on it does not look too good and shows a bit of the ply texture (not really flaking but looks kinda rough like not finished ply surface). The ceiling itself looks like it is also sagging a bit. Just wonder what would be the best way of action here: refinish the ceiling (how?) or take drastic approach and gut the master completely (btw old wainscoting has like 10 layers of paint) which is going to be very expensive and will have to wait a little while...

[HayZee518]

ZISSNER "KILZ" would hide the plywood texture. Kilz is a white shellac base with alcohol as a solvent. Before you do that you got to find out why it's sagging. Obviously it was put up to hide something underneath. Is the wainscotting secure? Is it fastened directly to the joists or is there furring strips.
A dropped ceiling with a grid system would work. You need about three inches.

[rmw]

you could prime the ply then skimcoat with sheetrock mud this would give you a nice smooth surface then you could texture or leave smooth. You should find out why it is sagging before proceeding. i would probely remove ply wood repair sag and replace with sheetrock.

[Tino]

Thanks guys. I will start with investigation first. My suspicion that ply covers old ceiling (we had double sheetrock ceiling in kitchen as well, had to rip it out). If sagging is repairable, I will try suggested methods to smooth the ply until we are ready to gut the whole thing.

BTW, is there any particular brand or any other good suggestion for sheetrock mud? I will need this to smooth the walls in several rooms. I do have old sheetrock there (circa 1921!) and its surface is very rough. It used to be covered in wallpaper, which came down easy but left a layer of glue as well.

[HayZee518]

use a high powered stud finder and use 2 1/2" sheetrock screws from the center out 6 inches on center to bring the ply into plumb. use regular sheetrock mud and one gallon of latex flat paint mixed into it for a skim coat. if there's too much mud, split it up into another empty poly bucket.