Cracked Drywall
easy 1–3 h
Tools: utility knife, 6-inch and 10-inch taping knives, sanding sponge, dust mask, flashlight · Materials: paper or fibreglass mesh joint tape, all-purpose joint compound, primer and matching paint
Steps
- Photograph the crack against a ruler and check it again in a month — a crack that is not growing is cosmetic; one that lengthens or widens is movement.
- Cut a shallow V along the crack with a utility knife so the compound has something to grip, and brush out the dust.
- Lay a strip of paper tape into a thin bed of compound over the crack and press it flat with the 6-inch knife.
- Apply two more coats, each wider than the last, letting each dry fully; feather the edges with the 10-inch knife.
- Sand lightly with a sponge, prime the patch, and paint the whole wall section to a corner so the sheen matches.
- For nail pops, drive a new drywall screw 5 cm (2 inches) above and below the pop, then patch all three spots.
Stop and call a pro if
- the crack runs diagonally from a door or window corner and is wider than 3 mm (⅛ inch)
- the crack keeps reopening after a taped repair
- the wall bulges, feels damp or the crack has a brown stain along it
- doors nearby have started sticking or gaps have opened at the ceiling
What a pro does that you can't
A drywall contractor floats a whole seam invisibly, and a structural engineer or foundation specialist checks a returning diagonal crack for settlement before anyone patches it again.
DIY cost: $15–40 in tape, compound and paint