My husband and I are installing (or reinstalling, actually) a shower in the basement. I am tiling the walls and floor, but I don't want to tile the ceiling. Can we use some of the left-over cement backerboard for the ceiling and paint it? I'd rather use the cement board because of it's water resistance, instead of drywall, but I need to know if it can be painted?
Thanks for any help,
M.

Yes you can.

Use a good primer/sealer (I prefer BIN over Kilz) followed by 2 coats of a good mildew resistant bathroom paint.

Thanks for the quick reply, Rickj. Greatly aprreciated :)