Dry Lining Calculator — Studs, Plasterboard & Fixings

Dry lining is a method of finishing internal walls using plasterboard fixed to a framework of metal studs or timber battens, rather than applying wet plaster directly to the masonry wall. It is faster than wet plastering, provides a cavity for insulation and services, and gives a flat, smooth finish. It is the standard method for internal walls in most UK new builds. You will also need plaster beads for any corners — see our Plaster Bead Calculator. For adhesive-fixed boards, see our Dot and Dab Calculator.

Metal C-studs and timber battens should be spaced at 600mm centres (measuring centre to centre). This spacing corresponds to the standard plasterboard width of 1200mm, so each board edge lands on a stud. Some applications (e.g., heavy wall loads) may require 400mm centres. Always follow manufacturer guidance. See our reference of standard plasterboard sheet sizes for walls for all widths and lengths.

The most common metal stud sizes in the UK are: 50mm C-stud for general partition walls, 70mm C-stud where more insulation depth is needed, and 92mm or 146mm C-stud for taller walls or enhanced sound insulation. The matching U-channel (track) is fixed to the floor and ceiling. British Gypsum GypLyner and Knauf systems are the most widely used.

Insulated plasterboard (also called thermal board or thermal laminate) is a plasterboard sheet bonded to a layer of rigid insulation (usually PIR or EPS). It is fixed directly to the wall using adhesive (dot and dab method) or mechanical fixings. Brands include British Gypsum Thermaline and Kingspan Kooltherm K17/K18. It is the quickest way to insulate and line a wall. Use our Dot and Dab Calculator if you are fixing thermal boards with adhesive.

For plasterboard fixed to metal or timber studs, British Gypsum specifies drywall screws at 300mm centres along every stud, with the board perimeter also fixed at no more than 300mm centres (tightened to 200mm only at external angles/corners). A standard 2400 × 1200mm board on studs at 600mm centres crosses 3 stud lines (two edges plus one centre), which works out to approximately 36 screws per board (about 27 if you only count the field at 300mm along the studs). Use 25mm screws for 9.5mm board, 32mm for 12.5mm board, and 38mm for 15mm board or double-boarded walls.