Scrape off any peeling or chipping paint using a broad-edge paint scraper. Use gentle pressure to lift the edges of the paint without gouging into the walls. Brush any lightly flaking areas with a wire brush to buff away the small flakes. Wipe the walls with a dry towel to remove dust and paint flakes.
Patch cracks and nail holes with a joint compound. Fill in these small imperfections with a putty knife, scraping the edges smooth. Allow sufficient time for the compound to dry. Depending on your particular product, you might need to wait 12 to 24 hours.
Sand uneven areas of your walls with a fine-grade sandpaper, buffing the edges of your patches and scraped sections of old paint. Run your fingers over the sanded edges until you can't feel a difference in texture or depth. Wipe the walls with your dry towel to remove all traces of dust.
Remove the glossy finish from shiny walls with a liquid deglosser. Glossy finishes can cause fresh paint to pull away, bead and streak. Wear safety glasses and gloves when applying your deglosser. Allow the product to remain on your walls for the recommended amount of time, then rinse thoroughly with warm water and clean rags.
Clean your entire wall surfaces with tri-sodium phosphate, often called TSP. Pay special attention to greasy fingerprints on areas around doorjambs and light switches. Rinse the TSP from your walls with clean rags. Let the walls dry for at least 24 hours.
Wipe your dry, clean walls with a tack cloth to remove all traces of lint and dust. Apply an even coat of paint primer to ensure a good bond between your walls and your fresh coat of paint. Let the primer coat dry.
Check the label on your paint container for temperature specifications. Applying paint at the wrong temperature can lead to poor adhesion. Apply your fresh coat of paint to your prepared walls.