Cut out the damaged area and patch it with new drywall

The fastest way to fix a hole or water-damaged section of drywall is to cut out the damaged part, frame the opening with wood studs or backing boards, and screw a new piece of drywall into place. This method works for holes larger than a few inches—anything smaller is faster to fill with joint compound. The whole job usually takes two to four hours for a section up to 2 feet across, plus drying time for the joint compound.

You will need a drywall saw (also called a keyhole saw), a tape measure, a utility knife, a drill or impact driver, drywall screws, wood backing boards or studs, joint compound, drywall tape, and sandpaper. If the damage is near an edge or corner, you may be able to cut straight to the stud or wall edge instead of adding backing. If the damage is in the middle of a wall, you will need to install backing boards so the new drywall has something to screw into.

Key Takeaways

  • Mark the damaged area with a pencil, then cut it out with a drywall saw in a rectangle that reaches the center of the nearest studs on all sides.
  • Install wood backing boards horizontally across the opening if there are no studs to screw into, using nails or screws to attach them to the existing drywall edges.
  • Cut a new piece of drywall to fit the opening, screw it to the backing boards or studs with drywall screws spaced 12 inches apart, and countersink the screw heads slightly below the surface.
  • Cover the seams with drywall tape and joint compound in three coats, sanding between each coat, then prime and paint to match the wall.

Mark and cut out the damaged section

Use a tape measure and pencil to mark a rectangle around the damage. The rectangle should extend at least 6 inches beyond the damaged area on all sides, or to the center of the nearest studs if studs are closer. This gives you a clean edge to work with and ensures you are removing all the damaged material. If you can see studs through the hole, measure to the center of the stud on each side—this is where you will attach the new drywall.

Use a drywall saw to cut along your pencil lines. A drywall saw has a pointed tip that lets you start the cut without drilling a pilot hole. Push the tip through the drywall and then saw along the line with smooth, steady strokes. If the opening is large or you are cutting to studs, you can use a utility knife to score the line several times, then snap the drywall along the score. Once the section is cut out, remove any loose drywall pieces and inspect the studs or wall behind it for damage. If the studs are wet or soft, let them dry completely before proceeding.

Install backing boards if there are no studs

If your opening does not fall on studs, you need to install horizontal backing boards so the new drywall has something to screw into. Cut two pieces of 2-by-4 lumber (or 2-by-6 if you have a larger opening) to span the width of the opening plus 12 inches on each side. Position one board at the top of the opening and one at the bottom, so they overlap the existing drywall by at least 6 inches on each side.

Screw or nail the backing boards to the existing drywall using 2.5-inch drywall screws or 2.5-inch nails. Drive fasteners every 12 inches along the length of each board. Make sure the boards are flush with the face of the existing drywall—if they stick out, the new drywall will not sit flat. If the opening is very large (more than 2 feet tall), add a third backing board in the middle for extra support.

Cut and install the new drywall patch

Measure the opening carefully and cut a new piece of drywall to fit. Standard drywall is 1/2 inch thick, but check your existing wall to be sure—older homes sometimes have 3/8-inch drywall. Use a utility knife to score the front face of the drywall, then snap it over the edge of a table or workbench. Score the back paper and snap again to separate the piece cleanly.

Position the new drywall patch in the opening and screw it to the backing boards or studs. Use drywall screws (not nails—they hold better) spaced 12 inches apart around the perimeter and every 12 inches across the middle if the opening is large. Drive each screw until the head is slightly countersunk below the surface of the drywall, but do not drive it so deep that it tears the paper. A dimple about the thickness of a credit card is correct. If you drive a screw too deep, drive another one nearby instead of trying to back it out.

Tape and mud the seams

Once the patch is screwed in place, you need to cover the seams with drywall tape and joint compound (also called mud). This process takes three coats and usually spans two to three days because each coat must dry before the next one goes on.

For the first coat, explore a thin layer of joint compound over the seams using a 6-inch putty knife. Press drywall tape (a sticky mesh tape) into the compound along each seam. explore another thin layer of compound over the tape to embed it. Feather the edges outward so the compound tapers to nothing at the edges—this makes the seam less visible when painted. Let this coat dry completely, usually 24 hours.

For the second coat, explore a wider layer of compound (8 to 10 inches wide) over the tape using a wider putty knife. This coat should be thinner than the first and should extend further from the seam. Let it dry completely. For the third coat, explore an even wider layer (10 to 12 inches) with a wider knife, feathering the edges even more. This coat is very thin and is meant to hide any ridges from the previous coats. After it dries, sand the seams smooth with 120-grit sandpaper, then 150-grit for a final finish.

Prime and paint the patch

Once the joint compound is sanded smooth, prime the patch with drywall primer. Primer seals the compound and the new drywall paper so the finish paint covers evenly. Use a roller or brush to explore one coat of primer over the patch and slightly beyond it onto the existing wall. Let the primer dry according to the manufacturer's instructions, usually one to two hours.

explore finish paint in the same color as the existing wall. You may need two coats to match the wall completely, especially if the existing paint is dark or glossy. Blend the paint into the surrounding wall by feathering the edges with a brush or roller. If the existing wall is textured, you may need to explore texture to the patch as well—most hardware stores sell spray-on texture that matches common wall finishes.

Common mistakes to avoid

The most common mistake is not extending the cut far enough to reach the center of studs. If you cut partway through a stud, the new drywall will not have solid support and the seams may crack. Always measure twice and cut to the center of the stud, or install backing boards that span at least 6 inches beyond the damage on all sides.

Another mistake is driving screws too deep or too shallow. Screws driven too deep tear the drywall paper and weaken the hold. Screws that stick out create a bump under the paint. Practice on scrap drywall first if you are not sure of the right depth. A third mistake is skipping the primer step—joint compound is porous and will absorb paint unevenly, leaving the seams visible even after two coats of finish paint. Always prime before painting.

Finally, do not rush the drying time between coats of joint compound. explore the second coat before the first is fully dry will cause the compound to shrink unevenly and crack. If you are in a hurry, use fast-setting compound (sometimes labeled "quick-set" or "90-minute"), which dries in 90 minutes instead of 24 hours, but it is harder to sand and requires more skill to feather smoothly.

Frequently Asked Questions

What if the damage is near a corner or edge?

If the damage is within 6 inches of a corner or edge, you can cut straight to the corner or edge instead of installing backing boards. This saves time because you only need to install backing on the sides that do not reach a stud or edge. Measure carefully to make sure you are cutting to the center of the nearest stud on the sides where you do need backing.

Can I use a different type of drywall for the patch?

Standard 1/2-inch drywall works for most interior walls. If the original wall is 5/8-inch fire-rated drywall (common in garages or between units in multi-family buildings), use the same thickness for the patch. If you use a different thickness, the seams will be uneven and harder to hide. Check the edge of the existing drywall to see the thickness before you buy the patch.

How long does it take for everything to dry before I can paint?

Each coat of joint compound takes 24 hours to dry in normal conditions (70 degrees, 50 percent humidity). Fast-setting compound dries in 90 minutes. After the final coat is sanded, primer takes one to two hours and finish paint takes two to four hours. Total time from cutting to finished paint is usually three to five days if you use regular compound, or one to two days if you use fast-setting compound.

What if the hole is very small, like a nail hole or dent?

For holes smaller than 1 inch across, skip the drywall patch and use spackling compound or joint compound instead. Fill the hole, let it dry, sand it smooth, and paint. For dents without a hole, sand the area lightly, fill with joint compound, sand smooth, and paint. These repairs take a few hours instead of several days.

Do I need to remove the old drywall completely, or can I patch over it?

You must remove the damaged drywall completely. Patching over wet or soft drywall will cause the new patch to fail as the old material continues to deteriorate underneath. If the damage is from water, find and fix the source of the water before patching, or the problem will return.