Most whole sheets of drywall are 4 ft (1. 2 m) wide. Choose a length of 8 ft (2. 4 m), 9 ft (2. 7 m), 10 ft (3. 0 m), or 12 ft (3. 7 m), depending on the height of your room. Measure the last gap at the top, middle, and bottom in case your wall is uneven.
If you are left-handed, you may prefer to line up the left edge of the square with your marks.
Take the knife out and place it at the bottom of the drywall to make the rest of your cut in an upward direction. If you are not tall enough to reach the top of the drywall sheet, you can lay it down on the floor to make your cuts instead. Use a new, sharp blade since a dull blade could tear the paper on your drywall. [4] X Expert Source James MansfieldConstruction & Design Specialist Expert Interview. 13 May 2021.
Trying to break a thin strip of drywall after only scoring the front will cause it to break off in many uneven chunks.
If the core does not break completely with one bump of your knee, apply more pressure to the unbroken areas with your knee, foot, or fist. If you scored the drywall on the floor, lift the drywall on one side to break the core at your cut.
If you have very large bumps because the core broke unevenly, use your utility knife to carve these pieces away before using the rasp to file them down.
Hang your drywall after you have finished making it the size that you need it to be. If your section of drywall is slightly too large, shave it with a rasp until it fits.
This process works for any hole you need to cut: holes for windows, doors, outlets, or light fixtures will all use the same measuring process. Use a ruler and pencil to draw the sides of your hole by connecting your corner marks directly on the sheet of drywall. This will give you an accurate line to follow while you’re cutting the hole. To cut a circular hole, measure from the edge of the drywall to the center of the circle that you need to cut. Use a compass tool to mark out your circle in pencil to the correct size of the hole.
Use caution when working around a stud if the drywall is already hung in place over your outlet or light fixture. If you have a difficult time inserting the saw into the drywall for the first part of the cut, make a small slit with a utility knife first and then insert the keyhole saw into that before you start sawing. If you have a larger job, consider using an oscillating tool. Be sure to wear safety goggles and gloves when you’re using a saw.
If your hole is in the middle of the drywall sheet, pierce the drywall with a utility knife to start your cut, then insert your saw into the slit to begin. Wear safety goggles and gloves to protect your eyes and hands while you’re using a saw.
A hammer can cause some damage to drywall. Don’t hammer the outer wall that you’re keeping; tap only the middle of the hole since you will be discarding that piece of drywall.
