How to Fix Painted Walls

Analyze the damage in the wall to determine which materials you'll need to make the repair. For cracks, compound mud will cover it sufficiently, while a screen-mesh patch repairs doorknob holes. New drywall will be needed to replace large areas with damage.

Prepare the wall for repair. Sand down cracks with fine-grit sandpaper; use scissors and cut and stick a screen-mesh patch over holes. If you need new drywall, cut it to size with a serrated knife and and secure it with drywall screws by drilling the drywall into framing posts.

Patch the repair with joint compound. Scoop out the compound with a large putty knife and spread it onto the crack or repaired hole at a 45-degree angle. When covering the repair, you'll want to extend the compound out a few inches past the edges of the repair for a seamless finish. Allow the compound to dry thoroughly, and then sand down with fine-grit sandpaper to smooth. Add two or three coats of compound and sand between each coat if needed.

Paint the repaired area with wall primer and allow it to dry. Paint over the primer using the existing wall color already in the room. If you no longer have leftover original paint, you'll need to primer over the entire room and re-paint either with a new color or find the original color if possible.