How to Repair a Drywall Ceiling
Drywall ceiling repairs take several forms, from repairing the drywall after a plumbing or roof leak, to fixing sagging or wavy ceilings due to poor workmanship or structural defects. While the materials used to repair a ceiling is the same as a wall repair, the methods used are slightly different.
One common problem in newer homes are sagging or pillowed ceilings caused by the wider span of roof trusses coupled with the weight of the insulation and ½-inch drywall being used.
Another cause of wavy ceiling finishes could be excess humidity during the construction process. The moisture is absorbed into the drywall causing it to sag under its own weight.
Controlled-density (CD) or sag-resistant (SR) drywall can be used in place of regular gypsum board.
Tools and Materials
Sanding Sponge or Pole Sander
Drywall Screws – 1 5/8-inch, 2-inch, and 3-inch
2x2s or 2x3s
Drywall – ½-inch or 5/8-inch
If the ceiling repair is below the attic, the insulation must be cleared away and replaced after completion. Always wear protective clothing including goggles and a dust mask. Use caution when working in attics to avoid stepping on unsupported drywall.
Score repeatedly with a sharp blade until you cut through the gypsum and paper. Remove any screws or nails holding the drywall up and pull the damaged wallboard free. Use 2-inch drywall screws to secure the remaining drywall back in place.
If the patch is caused by a leak the area should be cut open and left to dry out to eliminate any mold or mildew before closing the ceiling back up.
Locate the nearest ceiling joist or truss where the drywall is dry and stable. Use a stud finder to locate the framing members or a 10d finish nail to probe the ceiling until you hit wood. If the attic is above the repair, you can locate the framing from above and push a nail down through the drywall.
Drywall cutout to expose framing and piping
Instead of trying to cut down the center of the ceiling joists, you can cut along the edge of the joist and attach wood stripping down the edge to screw the drywall patch into. Use at least a 2x2 wood strip to prevent splintering when the drywall is screwed into it.
For smaller patches you may be able to use drywall clips to support the free edges. For larger repairs install nailers between the joists using 2x3s or 2x4s. Use 3-inch drywall screws to screw the nailer into the joists. You can place one screw on an angle in the open section and another up through the face of the drywall going through the nailer and the ceiling joist. When you finish the patch the spackle will cover the screw hole.
Drywall Clip - Metal or plastic drywall clips can be used to replace a third stud at a corner, at a partition intersection backing stud, or in the ceiling to replace a nailer.
Measure and cut a new piece of drywall for the patch. Use a drywall rasp to remove any excess gypsum along the cut edges and to make adjustments to the patch.
Nailers installed to support drywall edges
Mount the replacement piece in the created opening with screws. If clips are set, be careful not to overtighten. Consider a lift for hoisting larger/numerous sections.
Secured Ceiling Patch
Apply joint compound to the seams and apply paper tape resulting in at least and inch and a half overlap at the corners. Later, knock down high points of the dried compound with a hand sander, for an even grade throughout. Apply two more coats using wider finishing knives.
Allow each coat to dry completely. Sand the final coat with a sanding sponge for smaller patches or a sanding pole with 120 grit sandpaper.
Repairing Wavy Drywall
Sagging or pillowing in a ceiling may be caused by undersized drywall that is hung on roof trusses which are typically spaced on 24-inch centers. The solution involves replacing the 1/2-in. drywall with 5/8-in. or installing furring strips and a second layer of 5/8-in. drywall which will not sag under the wider span.
If the idea of ripping out the old drywall and removing the attic insulation does not appeal to you, you can save a lot of time by installing a new ceiling below the old one. Add 1 x 3 furring strips screwed into the ceiling trusses. You place the furring strips right over the trusses, but if your ceiling is sagging ½ to ¾-inch you should use 2x2s and install them perpendicular to the trusses. Screw the 1x3s to the truss framing with 2-1/2-in. drywall screws spaced every 16 inches. Hang the new 5/8-in. drywall, tape and apply 3 coats of lightweight spackle to finish.
If there are any ceiling fixtures you will have to add extensions to the electrical boxes so they are flush with the new ceiling.