How to Cover Wide Cracks in Walls

Cut around the edges of the crack with a utility knife. This will give the joint compound a clean space to fill in the crack

Vacuum or brush away any loose particles of plaster or drywall.

Put a small amount of joint compound on the edge of a 6-inch taping knife and fill the crack. Feather out the edges of the joint compound so that it blends in with the rest of the wall.

Cover the cracked area completely with drywall tape.

Push the tape against the compound with the taping knife. Scrape over the taped area with a 12-inch taping knife to remove excess joint compound and smooth out the edges.

Apply joint compound in a thin layer over the drywall tape with the 6-inch knife. Extend the compound 6 inches beyond the crack in all directions. Feather the edges of the joint compound so that it blends with the rest of the wall.

Allow the patched area to dry for at least 12 hours.

Sand the area lightly with 220-grit sandpaper. Wipe away the dust with a tack cloth.

Repeat Steps 6 through 8 twice, using a 12-inch taping knife. As you apply each layer of joint compound, make the repair level with the surrounding wall surface.

Touch up the area with primer. After the primer is dry, paint the repaired area to match the rest of the wall.