How to Fix a Corner Wall Crack

Loosen any plaster inside the crack with a paint scraper or old credit card. Continue to jiggle away the loose plaster, dirt and dust until the crack is clean.

Cover the crack fiber mesh drywall tape. Cut a piece of tape to fit the crack and run it vertically along the crack, pressing down as you go to adhere the tape to the wall. Smooth out the tape with the paint scraper or old credit card to remove any bubbles.

Apply a thin coating of joint compound over the fiber mesh tape. Using a putty knife, apply the joint compound using even, horizontal strokes. Apply slight pressure to work the joint compound into the fiber mesh drywall tape and crack.

Remove the excess joint compound by skimming it away with the putty knife. Allow the compound to set for at least one hour before lightly sanding it with a fine-grit sandpaper.

Apply two to three additional coats of the joint compound, once again skimming away the excess after each application. Allow each coat to set for at least 30 minutes before lightly sanding away the excess with the fine-grit sandpaper.

Sand the final coat of joint compound with the fine-grit sandpaper until the repair is flush with the surrounding wall. Wipe down the wall with a tack cloth to remove the sanding dust and apply a light coating of primer.

Allow the primer to dry for at least two hours before applying paint.