Preparing walls for painting is the first step to ensuring your home improvement project looks neat and professional when completed. Without proper preparation, stains, dirt and unrepaired damage will mar the paint finish. If there are large cracks or damage to your walls, complete your prep work several days before you want to paint. Spackle and drywall mud may need several days to dry.
Remove all of the furniture from the room if possible; an empty room is easier to prepare and paint. Take off any switch plates and outlet covers and put them in a safe place. Sweep the walls and ceiling clean of dust and debris. Scrape off any solid debris or peeling paint with a plastic scraper, being careful not to damage the wall. Use your vacuum hand tools to remove cobwebs from high corners and to clean up any debris that collected on the floor. Wash the walls with a solution of 1 tablespoon powdered laundry detergent mixed into one gallon of water.
Check the wall for holes, cracks, and damage. Use a trowel and wall spackle to fill in nail holes and minor cracks. Let the spackle dry completely, and then sand it to a smooth finish. If there are bumps or irregularities, smooth them down by sanding. Make larger repairs as needed. Remove sanding dust from the walls with a tack cloth and thoroughly vacuum the area a second time.
If the walls haven’t been painted previously, you will need to apply a coat of primer specially formulated for bare drywall. For previously painted walls, cover the areas you’ve sanded or repaired with primer, but don’t worry about priming the entire room. Apply painter’s tape around wood trim, moldings, or other areas on the wall that will not be painted, and you are ready to begin rolling on your first coat of new color.