Plasterboarding a wall is one of the most accessible DIY jobs you can take on, and the basic process is straightforward: fix sheets of plasterboard to a timber or metal stud frame using drywall screws, then tape and fill the joints for a smooth finish. The key to a professional result lies in getting the preparation, cutting, and fixing details right before any finishing compound goes near the wall.
Choosing the Right Plasterboard
Standard plasterboard works for most internal walls, but certain rooms call for specialist boards. Moisture-resistant plasterboard is designed for bathrooms, kitchens, and utility rooms where humidity is consistently high. Fire-resistant plasterboard slows the spread of fire and is used in garages, around boiler cupboards, and in loft conversions where building regulations require additional fire protection. Acoustic plasterboard reduces sound transmission between rooms, making it a good choice for home cinemas, music rooms, or party walls in shared housing.
For most domestic walls, 12.5mm thick boards are standard. Thinner 9.5mm boards are sometimes used on ceilings or where weight is a concern, while thicker 15mm boards offer better sound and fire performance. Boards come in several widths and lengths, with 1200mm x 2400mm being the most common size for walls.
Preparing the Stud Frame
Before you pick up a single board, check your stud frame is square, plumb, and solid. Use a long spirit level or a straight edge to identify any studs that bow in or out. A warped stud will telegraph through the finished wall as a visible bulge or hollow, so plane down any high spots or pack out low ones with thin offcuts of timber.
If you’re working with an existing wall where the studs are hidden behind old material, mark the centre of each stud on the floor and ceiling before you start boarding. This saves a lot of guesswork when you’re holding a heavy sheet in place and trying to find something solid to screw into. A stud finder or a few exploratory taps will locate them quickly. Standard stud spacing is either 400mm or 600mm centre to centre, so once you find the first one, the rest should follow at regular intervals.
Cutting Plasterboard Cleanly
Most cuts on plasterboard use the score-and-snap method, which is fast and produces surprisingly clean edges. Measure your cut, then run a sharp utility knife along a straight edge (a drywall T-square or a long spirit level works well), cutting through the paper face on one side only. You don’t need to cut deep into the gypsum core. Then stand the board on edge and push from the back to snap it along the scored line. The board will hinge open at the cut. Run your knife along the inside crease to cut through the paper on the back face, and the piece separates cleanly.
For cutouts around sockets, light switches, or pipes, measure the position carefully and transfer those measurements to the board. A drywall saw or padsaw handles internal cuts well. After any cut, a few passes with a rasp or surform cleans up rough edges so boards butt together tightly.
Fixing Boards to Timber Studs
Plasterboard on stud walls is fixed mechanically with drywall screws, not adhesive. The screws need to penetrate the timber stud by at least 25mm. For standard 12.5mm board, that means using 38mm or 42mm screws.
Start by offering the board up to the frame. If you’re working alone, a board lifter (a simple foot-operated lever) raises the sheet off the floor and holds it at the right height while you drive the first few screws. Leave a gap of roughly 10mm between the bottom of the board and the floor. This clearance prevents the board from wicking up moisture from a concrete slab and will be hidden behind your skirting board later.
Drive screws at 300mm centres along every stud the board crosses, both at the edges and across the middle (the “field”). Along the very edge of a board, keep screws at least 10mm in from the edge to avoid crumbling the gypsum core. At corners, tighter spacing of around 100mm gives extra strength. The screw head should sit just below the paper surface without tearing through it. If you rip the paper, the screw loses its holding power and you’ll need to drive another one nearby.
Board Orientation and Joint Layout
On walls, boards are typically hung vertically so a single 2400mm sheet runs floor to ceiling with no horizontal joint. If your ceiling height exceeds 2400mm, you’ll need to add a horizontal row of boards. In that case, fix the top boards first, then cut the bottom row to fit, leaving your gap at the floor where the skirting will cover it.
The most important rule with joints is to stagger them. Arrange your boards so that vertical joints on one row never line up with vertical joints on the adjacent row, like brickwork. This dramatically reduces the risk of cracking along the joint line because the board on the other side of the stud bridges the gap. For the same reason, avoid placing a joint directly above a door or window opening. Stress concentrates at the corners of openings, and a joint sitting right above that corner is almost guaranteed to crack over time.
Taping and Filling the Joints
Once all the boards are up, the joints between them need to be taped and filled to create a seamless surface. Start by applying a thin bed of jointing compound along each joint using a broad filling knife (a 150mm knife works well for the first coat). Press paper jointing tape into the wet compound, smoothing it flat and squeezing out any air bubbles or excess filler underneath.
Let this first coat dry completely, which usually takes overnight in a well-ventilated room. Then apply a second, wider coat of compound over the tape, feathering the edges out 150 to 200mm on either side of the joint. A wider knife or a dedicated taping knife makes this easier. A third coat, feathered even wider, hides the edges completely. The goal is a gentle, almost imperceptible transition from the flat board surface across the filled joint. Each coat should be thin. Building up with multiple thin layers produces a far better result than trying to get it right in one thick pass.
Fill every screw head with compound at the same time. These only need a couple of thin coats. Once everything is dry, a light sand with 120-grit paper smooths the surface ready for painting or plastering.
Internal and External Corners
Internal corners, where two walls meet, are taped with a fold of paper tape pressed into the angle and covered with compound on both sides. Work one side at a time, letting it dry before doing the other, to avoid disturbing the tape.
External corners, like the edge of a chimney breast or a boxed-out column, need a metal or plastic corner bead for protection. These are fixed over the plasterboard edge with dabs of compound or short screws, then plastered over with jointing compound. The bead provides a crisp, straight edge and protects the corner from chips and knocks that would quickly damage bare plasterboard.
Common Mistakes to Avoid
- Overdriving screws. If the screw tears through the paper face, it has almost no holding power. Set your drill’s clutch so the head sits just below the surface without breaking through.
- Tight-fitting boards to the floor. Plasterboard sitting directly on a concrete or tiled floor will absorb moisture and deteriorate. Keep that 10mm gap at the bottom.
- Lining up joints. Aligned joints create a weak line across the wall. Stagger them so each joint is backed by a solid section of board on the adjacent sheet.
- Skipping the tape. Filling a joint with compound alone, without tape, will crack within weeks. The tape is structural reinforcement, not optional.
- Rushing the filler coats. Applying the next coat before the previous one has fully dried traps moisture and causes bubbling or delamination. Patience here saves a lot of sanding later.