Minor ceiling cracks may eventually appear in many types of ceilings, including those made of plaster and textured or acoustical ceilings. These hairline cracks are no cause for concern but they are unsightly. The process of repairing ceiling cracks is virtually the same for all types of ceilings and requires only a quick trip to the hardware shop or DIY centre. For textured ceilings, an additional step is required to disguise the repair.
Spread plastic sheets over the floor of the room to make clean-up easier after completing the repair. Position a ladder under the cracked area of ceiling and put on safety glasses.
Climb the ladder and place the tip of a putty knife almost perpendicular to the ceiling and rub it gently over the crack to loosen any debris along the edges.
Open a tub of joint compound and scoop up 125 to 250 ml (1/2 to 1 cup) of the compound using a trowel. Lift the trowel to the ceiling and hold it at a 45 degree angle. Scrape the trowel over the ceiling to apply the compound in a thick coat. Continue until the crack is completely covered.
Wait 24 hours to allow the joint compound to dry completely. Put on the safety glasses and a dust mask. Sand the surface of the joint compound with fine-grit sandpaper until the surface is completely smooth and even with the remainder of the ceiling.
Examine the crack to see whether it is completely covered. If needed, apply more joint compound. Allow the compound to dry overnight and sand the ceiling again.
Open a can of primer and pour it into a paint tray. Apply the primer to the ceiling using a paint roller with an extension handle.
Allow the primer to dry overnight and paint the ceiling. If the ceiling is textured, spray the repaired area with a ceiling texture spray to create the dimpled appearance.
If the ceiling is made of plaster board, insert plaster screws through plaster washers and screw them into the ceiling along the entire crack using a screwdriver. Insert additional screws along the sides of the crack extending out into a grid 10 cm (4 inches) beyond the crack.