Repairing Drywall
Outline the damaged area with a carpenter square(a tool that looks like a square math ruler). The top and bottom of the rectangle should be an inch or so outside the damaged area. The sides should be centered over the studs on both sides of the hole.
Cut off the sides. When the saw blade runs into the studs, make a mark and measure over the stud 3/4 inch. This is the center of the stud, and the edge of the patch should be directly over it so both the existing drywall and the patch will have support. Cut along the line with a utility knife using several cuts, each one slightly deeper than the previous one.
Cut the support, then the path. Cut 1x3 or 3/4 inch plywood scraps 2 to 4 inches larger than the patch is high. Screw these supports vertically behind the opening to keep the patch from cracking. Hold the support in place and secure it with drywall screws. Avoid driving the screw through the drywall. Cut the patch to size. Measure the opening and use the framing square to lay out the measurement on a scrap of drywall and cut out with a utility knife.
Install the patch with 11/4 inch drywall screws. Position the screws as far as possible from the edges to avoid splitting or crumbling the drywall. Run strips of self adhesive fiberglass drywall tape around the installed patch, centering the tape on the seam. Then use a 9- inch putty knife to spread drywall joint compound across the patch and tape to create a smooth, flat surface. Let the compound dry overnight, sand, and apply a second coat of joint compound. For the smoothest patch, sand the surface to smooth out any irregularities, then spread a third coat with a 12-inch putty knife.
Dry Wall Crack Repair
When you repair drywall, you have to make the situation worse in order to make it better. To fill a narrow drywall crack, widen it slightly. brush off any loose particle.
Fill the wide crack with lightweight surfacing compound, using your finger to apply.
Smooth the area by applying one or more thin coats of the surfacing compound. When the patch is dry, sand and prime it for perfection.
