Surface Preparation

Every coating is only as durable as the surface beneath it; the surface must be clean, dry, dull, and sound before painting.

Wash chalky, dirty, or contaminated surfaces (pressure wash or detergent) and remove grease and oil with an appropriate degreaser, then rinse.

Kill and remove mildew before painting, commonly with a bleach-and-water or dedicated cleaning solution followed by a rinse; painting over live mildew lets it grow through the new film.

Scrape and remove loose or flaking paint down to a tightly adhered edge, then sand (feather) the edges smooth so repairs do not telegraph.

Patch nail holes and cracks with spackle or joint compound in thin coats to minimize shrinking and cracking; sand flush when dry.

Sand bare wood with the grain to remove raised fibers, and remove all sanding dust before priming for proper adhesion.

Test concrete and masonry for moisture (calcium chloride or taped plastic-sheet test) and check wood with a moisture meter before coating.

Remove efflorescence (soluble salts) by dry brushing or masonry cleaner and correct the moisture source before painting.

Allow new masonry to cure and address high alkalinity, using an alkali-resistant primer to prevent saponification of the coating.

Prime new drywall with a PVA sealer to equalize porosity between paper and joint compound and prevent flashing.

Seal knots and sap streaks in softwood with a stain-blocking primer so resins do not bleed through the finish.

Prime bare ferrous metal with a rust-inhibitive primer and clean or use a compatible primer on galvanized metal to avoid adhesion failure.

For pre-1978 housing, follow the EPA RRP Rule: use certified firms, contain the work area, avoid open-flame and uncontrolled dry sanding, and clean with HEPA vacuuming and wet methods.

Control respirable crystalline silica from cutting or grinding masonry with wet methods or vacuum dust collection per Cal/OSHA.

Deglossing slick surfaces and confirming the substrate is sound completes prep before applying primer or finish coats.