Patching drywall holes ranging from 3 to 12 inches is simpler than it appears. This is a basic repair that is best accomplished by securing a section of wood backing at the hole and filling the hole with a new piece of sheetrock.
Wood backing comes in the form of large painter stir sticks or 1x4 boards depending on the size of the holes. These items are available at home improvement stores. You may also use scrap pieces of wood you have on hand.
Small quantities of replacement drywall are also sold at home improvement stores and many hardware stores. A small sheet 12 inches by 12 inches will likely suffice. Most drywall used in homes has a thickness of 1/2 inch or 5/8 inch. Check the thickness of your drywall before you make your purchase.
Tool and Supplies
The necessary tools and supplies for patching drywall holes are relatively inexpensive. You may already have some of these items.
Phillips Head Screw Driver
6 inch Joint Knife
12 inch or 14 inch drywall knife
Replacement Drywall – make sure it is larger than the hole
Several 1¼ inch flat head drywall screws
Wood backing for holes 5 to 12 inches - A scrap piece 1x4
Wood backing for holes 3 to 5 inches – 1 or 2 painter’s stir stick (5 gallon size)
Drywall joint compound
Drywall tape – fiberglass
Sanding block – med/course or medium
Prepare the Hole
Patching drywall holes begins with removing all of the loose damaged drywall at the hole. This can easily be done by cutting the loose sheetrock with a utility knife and pulling it away from the hole. Always check for electrical wires before cutting.
Measure the hole at its widest and tallest points. Cut a piece of the new drywall in the shape of a square or rectangle, just slightly larger than the hole’s measurements. Use the utility knife to make this cut.
Take the square or rectangular piece of new drywall and hold it over the hole making sure that the hole is fully covered. With your pencil, trace a line around the new piece of drywall. Cut along the traced pencil lines, using the keyhole saw. Try to make an accurate cut on the lines so that the new piece of drywall will fit properly.
Install Wood Backing
Providing adequate wood backing for the hole is the key to patching drywall. For holes ranging from 3-5 inches, use a large painter’s wooden stir stick as backing for the hole. Make sure that it is at least 6 inches longer than the height of the hole.
For holes ranging from 5-12 inches, use a piece of 1 x 4 inch wood as backing. Cut the board approximately 4 inches longer than the height of the square or rectangular hole. Try to use wood pieces for backing that are at least ½ inches thick.
Insert the cut piece of wood backing inside the hole and situate it vertically leaving at least an extra 2 inches at the top and bottom of the hole. Leave 1 to 2 inches of space at each side of the backing so that you can more easily hold onto it. Drive 2 of the 1 ¼ drywall screws through the existing drywall and into the wood backing at the top and bottom of the hole. Try to position the screws 1 inch above the top of the hole and 1 inch below the bottom of the hole. For the narrower painter stir sticks, position the screws 1 and 2 inches above the top and bottom of the hole.
Make sure to countersink the screw heads slightly below the surface of the drywall so they can be covered with joint compound.
If the hole is considerably wider than the wood backing, repeat the process. The goal is to not leave gaps more than 2 or 3 inches wide behind the hole.
Take the new piece of drywall and place it in the hole. Screw the drywall into the wood backing using the 1 ¼ inch drywall screws.
The job is not yet completed. Patching drywall holes requires finishing off the joints that form around the perimeter of the patch. Place a piece of fiberglass drywall tape, centering it over each joint. The fiberglass drywall tape is a self adhesive tape.
Pour a little dry mix (hot mud) joint compound into your mud pan. The 30 minute drywall joint compound is convenient for small projects because of its faster dry time. Add a small amount of water and mix thoroughly until the drywall compound paste has a smooth consistency
Spread an even layer of the drywall joint compound over the fiberglass drywall tape, using your 6 inch flexible joint knife. Try to cover the drywall tape with the joint compound, but take care not to apply too thick of a coat. Pull the edges of the mud tight with the joint knife. Your first layer of drywall joint compound should be about 6 inches wide, extending about 3 inches from each side of the joint. Perform this process at each of the 4 sides of the drywall patch. For patches that are 8 inches or less, most of the patch will be covered with drywall compound.
After the first layer of drywall joint compound is dry, you are ready to apply a second and final coat of drywall compound. Before you do this, carefully remove any high spots or ridges that could get in the way of the second coat. You can sand them with 120grit production sandpaper or a medium/course sanding block, or just lightly scrape them down with your 6 inch joint knife.
Mix a new batch of drywall joint compound. Spread an even layer over the joints, using a 12 or 14 inch drywall knife. Pull the edges of the mud tight with the drywall knife. The 2nd layer of drywall compound should completely cover any patch that is 12 inches or less and extend about 6 inches beyond all 4 edges of the drywall patch. You want to end up with a nice smooth swath of joint compound that is level with the adjacent areas of drywall. If you pull the joint compound tight with the drywall knife, you can avoid leaving a hump or bulge.
When the second coat of joint compound is dry, sand it smooth with a medium/course or a medium sanding block.
The final step to patching drywall is to match the existing finish. If the drywall is textured, try to texture the patch so that it will blend in with the rest of the drywall.