Re: Skim coat over popcorn ceiling
Joint compound is fine, topping compound would be better. The difference is that joint compound dries quite hard, making it more difficult to sand. Topping compound is more easily sanded when dry. Don't despair, you can still switch from using joint compound to topping compound to finish your ceiling. When it comes time to retexture your ceiling with orange peel or knock-down, you can still utilize what's left of both the topping and joint compounds by using them as the texturing medium. Simply add a little water to make them the consistency of pancake batter, pour into the texture hopper and have at it.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!