You are not really supposed to paint a popcorn ceiling but it can be done. However, you do not want to put much paint on the roller at all and only one coat. The popcorn ceiling just cannot take the weight of the paint. HINT: If you experience a patch or two coming down, paint ceiling and place patch back in place.
@Kimberly Barney I agree with this answer. Be aware that after you've painted the popcorn ceiling, the only way to get rid of it is to pull the whole ceiling down and start over with fresh dry wall.
isn't there a spray paint used for hiding stains on ceilings that would work ?
a kiltz type ?
It's just an unpleasant job. Either wet and scrape off the popcorn to start over with a flat ceiling or rely on 2 thin coats of quality ceiling paint and a roller. Every option is messy. Sometimes the paint will get the popcorn to loosen up. That old popcorn can fall off in once it gets soaked with paint. No fun if your ceiling is raining scab-like patches. Renting a paint sprayer may work better. Check You tube videos for guides.
Before scraping (or even washing) a popcorn ceiling make sure it's not asbestos. If it is, do NoT disturb the ceiling. Instead, attach a new layer of drywall over the popcorn ceiling to encapsulate the asbestos.
I wouldn't scrape it.....I'd just 'plank' it.....then just paint or stain-- :)
been fighting popcorn myself, there is no unmessy way to deal with it, personally I am getting rid of all of it in every room.