Frequently Asked Question How to prepare a surface for painting How do I prepare a surface before I paint? Surface preparation is the most important part of painting. Almost all common paint problems are associated with poor surface preparation and rarely due to failure of the paint itself. A clean surface will maximize paint adhesion and minimize stain bleed-through. Spackle any nail holes or cracks. Sand any rough spots lightly to a smooth finish. On smooth surfaces such as walls or doors a mild detergent and warm water applied with a rag or sponge is usually sufficient. Rougher areas such as masonry, brick or tile can be cleaned with a bristle brush. A stronger cleanser such as ammonia should only be used where grease and dirt build-up is substantial. Always rinse thoroughly to eliminate any detergent residue and allow the surface to dry completely. Prime the surface.