How to cut plasterboard
By Tom Drake | 1st August 2024 | 4 min read
Learning how to neatly and safely cut plasterboard is a vital skill when you’re building stud walls or repairing holes in a wall. In this guide, we show you how you can cut plasterboard sheets, cut angles, and cut holes in existing plasterboard walls.
Cutting plasterboard steps:
1. Mark the cut
Before you can start cutting your plasterboard, you need to mark out where you’re going to cut. Standard plasterboard has a backing side and an ivory side which faces outwards. Always mark and cut the ivory side.
Use a tape measure and pencil to mark out the width you need your plasterboard sheet to be. Then, draw a line where you’ve marked that will act as a guide for where you need to cut. The line needs to be straight, so use a ruler or a long spirit level as a guide.
2. Cut using a knife
With your plasterboard marked up, you can cut it down. You can cut plasterboard with any craft knife, but it’s best to use a knife with snap off blades. Blades will become blunt quickly if you’re cutting lots of sheets, and you need a sharp blade to get the best cut. Remember to always wear an appropriate dust mask and eye protection when cutting plasterboard.
Take your knife and carefully score the plasterboard along the marked line. You may need to do several passes along the board to cut it completely. To ensure a straight cut, use a ruler, spirit level, or any other straight edge to guide your knife and keep it on the line. You want to make a cut that’s roughly 4mm deep.
4. Cut the backing paper
Once you’ve snapped the board, turn it over and use a knife to cut through the backing paper.
If the edge of the plasterboard is rough where you’ve cut, run a plasterboard rasp along the surface to smooth it down.
Cutting angles in plasterboard
Using a plasterboard saw or jab saw is the easiest way to cut angles in plasterboard.
First, mark out the angle you need to cut. If you need to make a particularly difficult cut, use a piece of cardboard to create the outline of the cut on the wall. You can then trace the outline of the cardboard onto your plasterboard sheet.
With the board marked up, follow the line you’ve drawn on your plasterboard with a plasterboard saw. As a plasterboard saw will go all the way through the plasterboard, you don’t need to cut the backing paper afterwards.
Cutting holes in plasterboard
You may need to cut holes in plasterboard to create space for electrical sockets or light switches.
Before you cut any holes, use a detector to check for any pipes or electrical wiring that could be hidden behind where you want to cut. Once you’re confident you’re not going to cut through anything, use a pencil to mark the section you want to cut out.
Use a plasterboard hammer or the end of a plasterboard jab saw to create a small hole in the plasterboard inside the marks you drew on the wall. You can then place your plasterboard saw inside the hole and cut towards the lines you drew. Follow the lines with your saw until you can cut the section of plasterboard out.
Can I cut plasterboard with a jigsaw?
A jigsaw can be used to cut plasterboard and is particularly useful for creating curved cuts. However, a jigsaw will generate more dust than other methods and is more likely to damage the plasterboard sheets.
