Should I use TSP before painting?

Answer by  EJMCG (75)

You should prepare and clean your pre-painted walls with sugar soap, which removes dirt and grease. Unpainted walls should be primed with a diluted mix of 1:4 water to paint. Sand down rough areas or chipped paint and fill holes with suitable fillers before painting.

Answer by  slickytfox (235)

Inside it is not necessary. Washing your walls with a one to six ammonia water mix will remove any residues that would affect adhesion of paint to the surface. TSP is typically reserved for exteriors where they may be mineral build up.