How to Repair Drywall

stair and gypsum board wall interior decoration of home at construction site with copy space add text
credit: Bigpra/iStock/GettyImages
Large holes usually call for a patch of new drywall.

If you live in North America and your house doesn't have walls made of drywall, you're in the minority. Drywall is ubiquitous for reasons that include its resistance to fire and its low cost. Not to mention that it's made from gypsum, a resource the United States Geological Survey considers a perpetual resource. One of the most important reasons for the popularity of drywall, as far as do-it-yourselfers are concerned, is the ease with which you can repair damage. It's possible to mend cracked seams, holes large and smal,l and water damage, using just a few basic tools, some inexpensive supplies and a small investment of time.

The materials you use for drywall repair aren't always suitable for repairing plaster, which is a different type of wall covering. Plaster repairs call for a patching material that sets as it hardens, which usually isn't necessary for drywall repairs.

Repairing Minor Damage

Small defects in drywall include cracked, lifting or bubbling seams, and dents or holes smaller than 1 inch in diameter, such as might be caused by an impact when moving furniture.

Things You'll Need

  • Paint scraper

  • 1 1/2-inch drywall screws

  • Drill with driver bits

  • All-purpose joint compound (mud)

  • Drywall knife

  • 120-grit sandpaper

  • Paint primer and touch-up paint

  • Utility knife

  • Patching compound (plaster of Paris)

  • Spackling compound

Screwgun driving fastener into wallboard.
credit: Lowes
Where fasteners have loosened, drive new screws or nails into studs to secure the drywall.

Step 1 Resetting Lifting Seams

Scrape dried mud off lifting seams and drive drywall screws into the seams to reset them. Drive at least one screw into each of the drywall edges forming the seam, being sure to sink the screw head at least 1/8 inch past the surface of the paper.

Step 2 Taping the Seams

Coat the entire seam with mud, extending the mud about 2 inches past the seam. Lay drywall tape on the fresh mud, scrape the tape flat with a drywall knife and let the mud dry. Recoat with two more layers of mud, then sand the final coat with 120-grit sandpaper before priming and touching up the paint.

Sanding the drywall mud
credit: -lvinst-/iStock/GettyImages
After the mud has dried, a seam patch should be sanded smooth.

Step 3 Repairing Damaged Tape

Cut out bubbles with a utility knife and reset seams as needed. If any tape is loose, lift it and apply joint compound underneath, using a small wallboard knife, then press the tape flat. Sometimes there's no alternative to removing the damaged tape entirely and applying new tape. Apply two of three coats of mud over the repair with a drywall knife, then prime and paint.

Tips

If any surface paper has ripped off, spray the paper underneath with drywall primer before patching with joint compound. This aids adhesion and prevents further peeling.

Step 4 Fixing Small Holes

Fill 1- to 3-inch diameter holes with insulation or newspaper to provide a backing. Apply a coat of patching compound, which is a type of filler that sets hard in about 30 minutes. Scrape the patching compound flat, let it set fully, cover it with two or three coats of mud. Holes smaller than 1 inch in diameter usually don't need backing material. Just apply patching compound, then finish with mud.

For extremely small holes, such as those left by pins and picture hangers, use spackling compound to fill them. Spackling compound is a lightweight repair compound that dries quickly. Spread it with a paint scraper or putty knife and sand it lightly before painting.

Drywall being spackled.
credit: Viktor Ketal/iStock/GettyImages
Small holes can be patched by simply filling them with patching compound, applied with a drywall knife or putty knife.

Tips

Some pros like to fill holes with spray foam insulation. Squirt enough foam in the hole to form a small bulge and cut it flat with a saw when it dries. The hardened foam creates a great backing that you can finish with two or three coats of mud.

Wallboard patch.
credit: Lowes
Convenient peel-and-stick patch products offer an easy way to cover moderate-sized holes in drywall.

Repairing Major Damage

Large holes, such as those created by major impact or water damage, usually require that you replace sections of drywall. In many cases you can fasten the drywall to the existing studs, but when that isn't possible, you have to affix some type of backing material—usually plywood—to the studs to provide a surface for attaching the drywall.

Things You'll Need

  • Ruler

  • Pencil

  • Drywall saw or zip tool

  • 1/2-inch plywood

  • Wood screws

  • Drill with driver bits

  • 1 1/2-inch drywall screws

  • Utility knife

  • Drywall tape

  • Drywall knife

  • Joint compound

  • 120-grid sandpaper

  • PVA primer

  • Paintbrush

  • Paint

Step 1 Draw a Rectangle Around the Damaged Drywall

Use a ruler and pencil to draw a rectangle around the damaged area. It's best if the rectangle is large enough to overlap the studs to the right and left of the hole. If you have to make the hole larger to do this, it's worth it. A large hole isn't any harder to fix than a slightly smaller one. and it will save you from having to install backing material.

Step 2 Cut Out the Hole

Use a drywall saw to cut the hole. You may have to use a knife to cut the drywall that overlaps studs. Some pros like to use a rotary tool called zip tool to quickly cut drywall. If you use one of these, hold it carefully and work slowly, because it tends to wander. You can also cut drywall with a small handheld circular saw.

Backer strips in drywall hole.
credit: Lowes
Backer strips attached inside the cutout provides a surface for anchoring the drywall patch.

Step 3 Install Backing Material

Cut a piece of 1/2-inch plywood that fits inside the hole and exactly between a pair of studs. Tap it flush with the stud faces and fasten it to the studs with wood screws driven diagonally. Make sure to drive the screws fully so the screw heads are recessed. If the hole doesn't extend all the way to the studs, you can also fasten the plywood backer to the back of the existing drywall by driving drywall screws through the drywall and into the plywood.

Drywall patch being screwed.
credit: Lowes
A cut piece of scrap wallboard is screwed to the backer strips.

Step 4 Install the Drywall Patch

Measure the dimensions of the hole you have to fill and cut out a piece of drywall that fits more or less exactly inside it. It's okay if there are small gaps at the edges. Fasten the drywall to the studs or the backing material, using drywall screws.

Drywall patch, taped.
credit: Lowes
Patch the seams of your patch, then apply drywall mud and let dry before sanding smooth.

Step 5 Tape and Finish the New Drywall

Spread joint compound on the seams of the new drywall and lay tape on the mud. Scrape the tape flat with a wallboard knife. Let the tape dry, then finish with two or three coats of joint compound. Sand the final coat, prime with PVA drywall primer, then paint.


Chris Deziel

Chris Deziel

Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience, and he is also an avid craftsman and musician. He began writing on home improvement topics in 2010 and worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. He currently contributes a monthly property maintenance blog on Landlordology.com. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com.