“If it needs to be taken out due to drinking water destruction or consumer desire, it should initial be scraped to eliminate the higher spots and afterwards primed and skim coated (which calls for involving a few to five coats) till the ceiling is smooth, and afterwards primed and repainted.” http://andrexwtqm.arwebo.com/13658775/the-2-minute-rule-for-removing-popcorn-ceiling-with-shop-vac