Master the Basics of Drywall: How to Cut Drywall
Updated: Jul. 23, 2023
Learn about the five simple tools and basic techniques you need to successfully cut drywall.
With a few simple tools and special techniques you'll be cutting drywall like a pro in no time. Plus we'll show you how to plan your installation to make the best use of materials and avoid waste.
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A full day
Cut drywall faster with less waste
There are lots of stories out there about drywall projects gone bad. Inevitably, the story involves a circular saw and lots of dust. The irony is that drywall cutting is about the easiest, cleanest and quietest of all remodeling tasks. Even an “all-thumbs” do-it-yourselfer can master the basics of how to cut drywall without worry, and even a big, sheet-wrecking mistake only costs a few bucks to remedy. In other words, it’s work that’s easy on the mind. So consider hanging the rock yourself in the new family room and save the 30¢ per sq. ft. the pros generally charge (or much more for a small job!).
Buy These Tools Before You Start
A small investment in these five tools will make your job less frustrating and give you better, faster results.
- Drywall rip saw or electric drywall saw ($10; Photo 10)
- Drywall keyhole saw ($5)
- Surform rasp ($7; Photo 5)
- 4-ft. square ($15; Photo 2)
- Utility knife with extra blades ($5; Photo 2)
Sheets that fall over can injure you and even kill small children. Stack sheets with sufficient angle against the wall to prevent them from tipping easily.
Cutting to length and width
Photo 1: Lean the drywall
Lean drywall sheets at a slight angle against the last wall to be covered. Tear off the paper strip and flip the front sheet so all the finished faces are toward the room. To prevent warping, make sure the top edge is evenly supported against the framing.
Photo 2: Cut the face
Mark the length on the sheet of drywall along the top, then line up the right side of the tongue with the mark (lefties will be more comfortable lining up the left side of the tongue). Trap the bottom tip of the tongue with your foot against it, and starting at the top, score the paper about two-thirds of the way down. Finish scoring the paper from the bottom up. This method best protects you from slips of the knife.
Photo 3: Break the core
Lift one end of the sheet away from the stack and rest the sheet on the floor. A little knock from your knee will break the gypsum core so you can fold open the sheet.
Photo 4: Cut the back
Cut halfway down through the paper crease on the backside and finish the cut by coming up from the bottom. Catch the two halves by steadying the top with your free hand.
Photo 5: Smooth the rough edge
Smooth the rough core edge with a Surform rasp to make it smooth and square. (Rest the end of the sheet on your foot to smooth near the bottom.)
Photo 6: Cut thin strips
Cut off strips narrower than 3 in. by scoring both sides of the paper before snapping off the piece. Then rasp off the edge. If you try snapping with just one side scored, your strip will break off in small chunks and you’ll have a lot of rasping to do.
Photo 7: Rip sheets to length
Tip sheets to width by pulling the utility knife behind the 4-ft. square. Dig the blade into the aluminum tongue a little to hold the square against the sheet and then pierce the paper with the blade tip. It takes a bit of practice to get the hang of this. Score the sheet by pulling the top of the square and the knife the length of the sheet with both hands moving at the same speed. Here we show scoring two strips at the same time.
Photo 8: Snap the sheet
Lower the sheet close to the floor and snap the cut open with a soft karate punch. Make sure the floor is clear of scraps and screws so you don’t mar the face of the sheet.
Photo 9: Cut the back
Slice through the paper on the backside along each crease.
When you’re hanging drywall, there’s more at stake than saving money or keeping on schedule. The next step, taping, is the toughest part of drywalling, and the keys to saving time and effort are making accurate cuts and knowing the tolerances. If a taper has to fix poor cuts, big gaps and ragged ends, you’ll eat up all the money you saved by hanging the drywall yourself. This photo series shows the basics of drywall cutting and the tools you’ll need for fast, accurate cuts. It concentrates on cutting to length, cutting door openings and ripping.
Score, snap and cut
Ninety percent of the cuts made on any drywall-hanging job consist of three basic steps: scoring the front paper, snapping and folding open the sheet, and cutting through the paper on the back. You’ll use variations on that theme for nearly every cut. Other cuts are made with two types of drywall saws: a small keyhole- type saw for short cuts (mostly electrical box openings) and a larger coarse-tooth saw for longer cuts like those around doors .
Working with drywall
Drywall is really just a simple sandwich of mined gypsum rock encased in a wrapper of recycled paper (hence one brand name, Sheetrock). Although neither component has much inherent strength, together they form a remarkably strong, highly fire-resistant wall sheathing. When you score the paper with a utility knife, the crumbly gypsum breaks cleanly, directly in line with the score.
When you’re scoring with a utility knife, use only enough pressure to barely cut the paper. Cutting deeply into the gypsum core will only result in dull knives and a strained wrist. When the blade stops cutting cleanly, you’ll notice the paper begin to tear behind the knife edge as you score. That’s when it’s time to change blades.
Here are a few hanging tips to help the job go smoother and with less waste:
- Hang all horizontal surfaces like ceilings and soffit bottoms before you start on the walls.
- Do intricate layouts with the sheets lying flat on the floor rather than standing on edge. It’ll be easier to use straightedges and chalk lines.
- You have to cut openings for existing doors and windows before you hang the drywall sheets (Photos 10 – 12). Protruding jambs and insulation prevent cutting the sheets in place. Make those cuts while the sheets are standing against the stack instead of mounted over the opening. It’s helpful to have another person support the sheet to prevent breakage while you cut, especially if the cutout calls for narrow, fragile drywall legs on either side of the opening.
- Save waste by cutting pieces to length before cutting to width.
- Use 12-ft. long sheets instead of 8-footers if you can handle the pieces and wrestle them into the room. The leftover pieces will be longer, so they’re more likely to be useful, and you’ll have fewer joints to tape.
- As much as possible, minimize the number of joints, especially hard-to-tape butt joints.
How to cut door and window openings.
Photo 10: Saw the sides of openings.
To hold the drywall in place while you’re cutting, nail or screw it directly over wall openings whenever possible. Leave the area over the top of the opening unfastened until you finish cutting out the opening. Cut upwards with a drywall saw using the framing as a guide until you feel the saw hit the wood at the top of the opening.
Photo 11: Score the top of openings
Score the backside of the drywall along the top of the framing.
Photo 12: Cut the opposite side
Snap the flap up and cut through the front paper following the crease.
Attempting glove-tight joints will often result in cracks and broken corners when you’re forcing the sheets into place. You’re much better off cutting lengths 1/4 in. too short than trying to shoehorn in perfect fits.
When you’re cutting around windows and doors, remember that trim will usually cover at least 1 in. of the surrounding drywall, so you can afford wider tolerances. In fact, a 1/2-in. space between the opening frame and the drywall will often make applying wood trim easier.
But outside corners that get metal corner bead (Photo 10) are a different story. There, drywall joints should be overlapped and rasped as flush as possible. A 1/4-in. mistake on a corner can make fitting and nailing corner bead tricky and prone to cracks later. Also, avoid using the tapered edge of the drywall at any corner that receives corner bead. The recess of the taper won’t leave any gap between the outside bead and the flat drywall surface to fill with drywall mud.
Always span openings with a single piece of drywall. Joints that fall in line with the edges of openings are vulnerable to stress cracks. It’s even best to avoid joints that fall over the middle of openings because it’s hard to apply wood trim over built-up tape joints.
Use your 4-ft. drywall square to mark the centers of framing members before you hang the sheets; you’ll miss fewer studs and joists when you’re screwing off the drywall.
Required Tools for this Project
Have the necessary tools for this how to cut drywall DIY project lined up before you start—you’ll save time and frustration.
You’ll also need a keyhole saw and a drywall rip saw.
Required Materials for this Project
Avoid last-minute shopping trips by having all your materials ready ahead of time for this how to cut drywall project. Here’s a list.
Originally Published: September 30, 2019