How To Cut Drywall for Electrical Devices

Getting through a drywall job with efficient speed is a common goal. The sooner you complete this portion of the job, the sooner contractors can move on to the next steps. But being fast is nothing without accuracy. And there will be some cases where you may need to slow down, especially when cutting holes for drywall openings. We can tell you how to cut drywall for electrical devices.

What You Need

Equipment and Tools

• Circular saw
• Hammer
• Permanent marker
• Pencil
• Jab saw
• Power drill or driver

Materials

• Plywood
• 2x4 lumber
• Electrical boxes
• Nails
• Drywall
• Screws

Construct the Jig

The jig will help control the location and motion of parts and other tools. Build the jig first so everything else goes smoothly. Use it on a wall with a 2x4 bottom plate, and position the bottom of the electrical box 12 inches above the subfloor. You may need to alter the position of the 2x4 upward or downward.

The plywood should be about ½ inch thick. Place the face of the electrical box flush with the plywood. The box should sit about 1/16 inch back from the face of a 1/2 inch drywall. But if you’re dealing with thicker or thinner drywall, replace the plywood with a measurement that’s equal to the drywall.

Connect the Box

Now, it’s time to attach the box. The jig is for setting the electrical box and improving accuracy. Use the jig to help nail the box to the studs. Place the box directly on top of the jig. Get the positioning just right so it’s flush with the front edge of the plywood.

When you start to hammer the jib to the plywood, keep the hammer straight. Drive the nail in directly and avoid bending at an angle. If the nails start to go askew or crooked, gently yank them out and start over. Be sure you don’t strip the plywood on the way out. Test the sturdiness of the box to ensure it’s secured.

After securing the box to the plywood, test the wiring, install any other utilities behind the wall, and add insulation if necessary. Before even considering adding the drywall, make sure the wiring can get through the electrical box.

Check for Accuracy

Next, you need to check where the drywall installation goes. Some drywallers like to use another piece of drywall to measure and mark where the electrical box is. We recommend using a level. It’s a much more efficient and accurate way of getting things done.

Get the level out and place it directly on the floor. Position it flush against the electrical box and hold it tight. This will help you see if the electrical box is leveled and mark the location where you’ll need to cut. Take your pencil and mark the height of the box so you can transfer those measurements to the piece of drywall.

Then, make sure your level is plumb before traveling down the floor. Use a pencil or permanent marker to mark the bottom of the level. Use the bottom of the level to draw a line on the ground while the level is pressed against the box. Then, move the level over so it faces directly in front of the box, and draw another line on the ground. Now you’ve made new measurements for the drywall.

Grab the Sheetrock

Grab the piece of drywall and cover the opening area. Find the markings you made on the ground using the level. Place the level on the first ground marking and travel up to where you made the marking on the side of the level when you marked the height of the box.

Transfer those markings onto the piece of drywall and draw a straight line to make one side of the box. Move the level over to the second ground marking and make the other side of the box with the height marks.

Every time you move the level over, make sure it is tight against that marking. The slightest adjustment could make the whole thing too big or too small, and you’ll be forced to fix the cutting. Remember, it’s always better to measure 10 times and cut once than to cut 10 times and measure once.

If you prefer to use something darker than the pencil outline, you can stick a red marking sheet on the electrical box. Then lay the sheetrock against the electrical box and tap around the perimeter of the box with a wooden mallet. Remove the sheetrock, and you’ll notice a red outline reflecting the exact measurements of the electrical box.

Start Cutting

The next part is fairly simple. Grab your jab saw and start cutting out the outline you just made. But remember—safety first. Put on a pair of work gloves to protect your hands. Then, cut about 1/8 inch outside of each line. That should be enough room to create clearance so that the drywall fits easily.

Use that leeway to pull the drywall slightly away from the wall. Now, you can saw with longer strokes. Always start off small because you don’t want to run the risk of cutting through wires or nicking the electrical insulation. Keep the cut square to the surface of the drywall.

Finish Up

And this is the really easy part. Once your jab saw has sawed through the entire outline of the box, the cut-out should slide around the electrical box. If the hole is not big enough, it’s visible enough that you can see the places it needs to be bigger.

Use either the jab saw or something smaller, like a box cutter, to remove the residual pieces. Then, you’ll be ready to finish fastening the drywall. Use your power drill and screws to fasten the drywall in place. Don’t drive the screws in too deep because this could create cracks in the drywall in the future. Timothy’s Toolbox is the drywall tools store with everything you need for your project.

If you’re looking for ways to improve your accuracy and efficiency, our tools will get the job done for you—and our expert advice will help. We know more than how to cut drywall for electrical devices. Check out our other blog posts for more tips like these!