Interior Painting
How to Prepare Interior Walls for Painting
A practical guide to cleaning, repairing, sanding, priming, and protecting interior walls before painting.
Start by evaluating the wall
Look for grease, dust, peeling coating, nail holes, cracks, water staining, glossy areas, failed caulk, and movement at joints. Water stains or recurring cracks should be investigated before they are covered. Painting over an active moisture problem only hides evidence temporarily.
Clean, repair, and dull the surface
Remove ordinary dirt and residue with a cleaner appropriate for the surface, then allow the wall to dry. Repair holes and cracks with a compatible material and sand cured repairs smooth. Glossy coatings often need to be dulled so the next coating can bond; remove dust before continuing.
Know when primer helps
Primer is useful on bare drywall, patched areas, stains, porous surfaces, significant color changes, and surfaces where adhesion is uncertain. The correct primer depends on the substrate and the problem being solved. Follow the selected product label instead of assuming one primer works everywhere.
Protect the room before application
Move or cover furnishings, protect floors, remove switch plates when appropriate, and plan clean edges around trim. In a pre-1978 home, disturbing painted surfaces can create lead hazards; consult EPA lead-safe guidance before sanding or scraping.