How to Cut Drywall

How to Cut Drywall With a Utility Knife

1. Mark the Drywall

   • Make sure you have plenty of room to work, ideally 3 feet around the perimeter of the drywall sheet.
   • Mark the cut point on the drywall sheet with a pencil and a ruler.
   • For a quick cut, you only need to make one mark, then rely on the square pressed alongside the drywall's factory edge to indicate the line all the way across.

   Tip

   Before you start, make sure that the floor is flat, level, and clean. Uneven flooring may cause the drywall to crack or buckle. Debris will be embedded in the drywall. Clean the floor with a broom or shop vacuum.

2. Score the Drywall

   • Align the straightedge with the marks. 
   • Hold your fingers on the "T" area of the square, behind the direction of the cut. 
   • Run the utility knife lightly along the straightedge to score the drywall paper. 
   • With the square still in place, run the knife a second time along the same line applying slightly more pressure.
     

3. Flip and Cut the Drywall

   • Turn the sheet of drywall over carefully. 
   • Tilt the drywall up until it snaps along the cutting line (with the paper still in place). 
   • Tilt one side up to about 90 degrees and hold it in place. 
   • With a utility knife in your other hand, slice the paper holding the sections together. Be careful at the end of the cut to prevent tears in the paper.
     

How to Cut Drywall on Edge

If you don't have enough room to lay out the drywall sheet, this method allows you to both score the sheet and cut it while the sheet is on its edge.

• Rest the drywall against a wall horizontally with the lengthwise edge down. 
• With the 48-inch drywall square, firmly square the "T" end with the left side of the drywall. 
• With your utility knife, score a line as far as you can to cut the drywall sheet lengthwise. 
• Next, square up on the right side and complete the score. 
• Turn the sheet of drywall up onto one of its short ends. Reverse the sheet so that you are facing the back of the drywall (the unscored side). 
• Roughly locate the scored area and firmly hit it using your knee. The drywall should break perfectly along the score line. 
• With the backside still facing you, fold the two pieces inward until they form a V-shape. 
• Carefully run the utility knife down the drywall paper at the V-shape to cut the paper.

How to Cut Drywall Using a Drywall Saw

A drywall saw is an efficient drywall tool to cut through drywall, though it will produce rough drywall edges and significant dust.

• Apply pressure in either direction. The end of the blade has a knife-like point that can be used to start the cut regardless of which direction you choose.
• When sawing, try and use at least three-quarters of the blade.

How to Cut Out Drywall for Electrical Boxes 

In order to install an electrical box, you will need to make a clean, accurate cutout in the drywall. Here’s how.

• Measure the box edges and mark the drywall accordingly.
• Lay out all four sides of the box and cut through three sides with a drywall saw.
• Use a knife to cut the fourth side.
• Slice off the flap of drywall from the backside with the utility knife. If you need to widen the opening use the knife to do so.
• Slide the electrical box into the cutout and fasten to the drywall.

When to Call a Professional

Cutting drywall is a task that rarely requires professional assistance. But as part of a larger drywall installation project, you may want to have professionals cut, hang, mud, sand, and finish the drywall to avoid any problems.