Plasterboard Calculator — Sheets for Walls & Ceilings

A standard 2400x1200mm board covers 2.88m². With 10% wastage, you need roughly 0.38 boards per m², or about 1 board per 2.6m² of wall. For 3000x1200mm boards (3.6m² each), you need roughly 1 board per 3.27m².

12.5mm is the standard thickness for most walls and ceilings. Use 9.5mm for ceilings where weight is a concern or for curved surfaces. Use 15mm where greater mass is wanted, for example to improve sound insulation. Standard 15mm boards (Gyproc WallBoard) are Type A boards under BS EN 520 and are not individually fire-rated — for a fire rating you need a Type F fire board such as 15mm Gyproc FireLine, and the fire performance is determined by the complete tested system (board, frame, fixings and layers), not by the board on its own.

At 300mm screw spacing on a wall or partition you need roughly 28-32 screws per 2400x1200mm board, placed at 300mm centres on intermediate supports and around the perimeter. Ceilings need closer fixing — British Gypsum specifies 230mm in the field and 150mm at board ends — so a ceiling needs more screws than a wall. Screw length must let the screw bite about 25mm into the timber stud: use 32mm screws for 9.5mm board, 38-40mm for 12.5mm board, and 44-51mm for 15mm board.

Nogging is horizontal timber bracing between studs. It provides support at plasterboard sheet joints and for fixing heavy items like shelves or TVs. Typically installed at mid-height on walls and at the horizontal board joints on ceilings. Use 38x63mm or 38x89mm CLS timber to match your stud size.