Have the kids moved out? Is it time to paint their bed rooms the colors you want? Are the empty walls full of pinholes from their teen idol posters?
Before covering their questionable paint colors with your more refined choices, you may need to do some repair work.
Clean the walls. The quality of any paint job depends on how well you prep the walls. Start by pulling on a pair of big, thick rubber gloves and eye protection, and then wash your walls with the cleaner TSP (trisodium phosphate) and rinse them with clean water. This will be the start of the best paint job your house has ever seen. – Source
Cleaning your surface is the very first step we take when painting kitchen cabinets too.