What You'll Need
Before you start cutting, get these tools together. Don't skip any of them. I've tried shortcuts and they always cost more time than they save.
Essential tools:
- T-square or 4-foot drywall square ($12 to $25)
- Utility knife with fresh blades ($8, plus a pack of blades for $5)
- Tape measure, at least 16 feet ($10 to $15)
- Pencil (not pen, it bleeds through mud)
- Drywall rasp for cleaning edges ($9)
- Keyhole saw or rotary tool for cutouts ($8 for manual, $60+ for rotary)
Nice to have:
- Jab saw for larger openings ($12)
- Drywall lift or deadman braces (for ceiling work)
- Sawhorses or a cutting table
I spent about $65 on tools before my first project. Still using most of them 15 years later, except the utility knife which I lose constantly.
Step 1: Measure the Space
Measure the wall or ceiling area where the drywall will go. Measure width and height at multiple points because walls are rarely perfectly square.
Write down every measurement immediately. Don't trust your memory. I use a notepad and draw a little diagram of each wall with numbers written in. Takes an extra two minutes and has saved me from at least a dozen mistakes.
For outlets and electrical boxes, measure from the floor and from the nearest edge of the previous sheet. You need both dimensions to mark the cutout correctly. I measure twice, triple-check, and still manage to mess it up sometimes.
Step 2: Transfer Measurements to the Drywall
Lay the drywall on a flat surface, paper side up. Use your tape measure and T-square to mark your cut line.
Make a small mark at your measurement point on both edges of the sheet. Line up the T-square between these marks. Draw a light pencil line all the way across. Don't press hard. You just need to see it.
For cuts shorter than the full width, Uncle Frank taught me to hook the tape on one end, walk to my measurement, and make a small mark. Then I verify by measuring from the same point again. If the numbers don't match, something went wrong.
Step 3: Score the Paper Face
Position the T-square along your pencil line. Hold it firmly with your non-cutting hand. Run your utility knife along the edge of the T-square, pressing just hard enough to cut through the paper and into the gypsum core slightly.
One smooth pass. Don't saw back and forth. Don't try to cut all the way through. You're just scoring the paper.
Fresh blades matter here. A dull blade tears the paper instead of cutting it cleanly. I change blades more often than seems reasonable. They're cheap. Torn paper causes problems later during finishing.
Step 4: Snap the Drywall
This is the satisfying part.
Position the sheet so the scored line is at the edge of your work surface. Or stand it up and bend it toward the scored side. The gypsum will snap cleanly along your score line.
The first time I did this, I expected it to be hard. It's not. The sheet almost wants to break along the score. A light push and it pops.
Step 5: Cut the Back Paper
After snapping, the sheet is still connected by the paper on the back. Fold the piece you're removing away from the main sheet, exposing the back paper at the break.
Run your utility knife along the fold to cut through the paper. Done.
If your cut isn't perfectly straight, don't worry. The rasp can clean up minor wobbles. Big mistakes might need a second cut or a new sheet depending on how bad it is.
Making Cutouts for Outlets and Boxes
Cutouts require more precision. Measure the location of the electrical box from your reference point. Transfer those measurements to the drywall.
The Careful Method
Mark all four corners of the box. Use the T-square to draw the rectangle. Score all four sides with your knife, then use a keyhole saw or jab saw to cut out the middle.
This takes longer but produces clean results. Good for visible locations.
The Rotary Tool Method
Hang the sheet first with the box behind it. Use a rotary tool with a drywall bit to plunge through and trace around the box from the inside out.
Faster but requires a $60+ tool. Professional drywaller's method. Carlos uses this approach when he helps friends. Gets it done in seconds.
I tried it once. Cut through the wire. That was a $90 electrician visit. Stick with the careful method until you've got experience.
Common Mistakes to Avoid
- Measuring to the wrong edge: Make sure you're measuring to the correct edge of your previous sheet or corner. I've measured from the wrong side more times than I'll admit.
- Forgetting to subtract: If you need the drywall to fit inside a frame, subtract 1/4 inch for wiggle room. Tight fits are a nightmare to install.
- Cutting with dull blades: Change your blade every few sheets. Dull blades tear paper and make sloppy edges.
- Not verifying outlet measurements: Measure outlets at least twice. Cutting a new hole in the wrong spot is annoying. Cutting a new hole after the sheet is already hung is worse.
- Rushing the score line: One clean pass beats three sloppy ones. Take your time.
What to Expect
First sheet takes forever. Maybe 20 minutes if you're careful. By your fifth sheet, you'll be down to 5 minutes or less.
Expect to waste one or two sheets on a typical room-sized project. Mistakes happen. Factor that into your material estimate. Neighbor Dave always buys 10 percent extra. I've adopted that habit after running short on multiple projects.
The process gets faster with practice. Uncle Frank can measure and cut a sheet in under two minutes. But he's got four decades of experience. I'm still at about five minutes per sheet, and that's fine. Accuracy beats speed when you're paying for the materials yourself.