What size timber do I use for stud walls?

The standard timber for UK stud walls is CLS (Canadian Lumber Standard) at 89×38mm (marketed as 3×2 or 4×2). This is the most common size available from UK timber merchants like Travis Perkins, Jewson and Wickes. For taller walls over 2700mm or walls supporting loads, 89×63mm (3×3) may be needed.

Should I space studs at 400mm or 600mm centres?

Use 400mm centres for standard plasterboard fixing — this provides the best support for 12.5mm plasterboard and is the standard spacing used by most carpenters. Use 600mm centres when the void will be filled with insulation batts (which come in 600mm widths) or when using thicker 15mm plasterboard.

Do I need noggings in a stud wall?

Yes. Noggings (horizontal cross-pieces between studs) provide lateral bracing, stiffen the wall, and provide fixing points for wall-mounted items like radiators, shelves and TV brackets. Install at least one row at approximately 1200mm height. For walls over 2400mm, add a second row.

How do I frame a door opening in a stud wall?

A standard UK internal door opening is 926mm wide (for a 838mm door with 44mm lining each side). Frame it with two full-height king studs, two jack studs (trimmed to door height plus header), and a header piece across the top. The sole plate is cut out after the frame is erected.

How many plasterboard screws do I need per sheet?

Use approximately 32 drywall screws per 2400×1200mm plasterboard sheet. Fix at 150mm centres around all edges and 300mm centres in the field (middle of the board). Use 25mm screws for single-layer 12.5mm plasterboard, or 38mm screws for double-layer boarding. Always use drywall screws, not wood screws.

Stud Wall Calculator — How Many Studs and Plasterboard Sheets Do I Need?

Stud Wall Calculator

Calculate CLS studs, noggings, plasterboard sheets, screws and scrim tape for partition walls with door openings.

Wall Length

Total length of the partition wall

Wall Height

Floor to ceiling height (standard 2400mm)

Stud Spacing

400mm is standard for plasterboard

Door Openings

Standard opening 926mm wide

Board both sides

Plasterboard on both faces of the stud wall

Include wastage allowance

Adds 10% extra for cutting and waste

Wastage Percentage

10% is standard for stud walls

How We Calculate This

This calculator works out all the materials you need for a timber stud partition wall, from CLS studs and noggings to plasterboard sheets, screws and scrim tape.

Stud calculation

Studs = (Wall Length / Stud Spacing) + 1, adjusted for door openings. Each door opening adds 4 extra studs (2 king studs + 2 jack studs) but removes the studs that would fall within the opening width.

Noggings

Nogging rows = Wall Height / 1200mm (minimum 1 row). Noggings per row equals the number of bays between studs, adjusted for door openings where noggings are not needed.

Plasterboard

Sheets = (Net Wall Area × Number of Sides) / Sheet Area. Standard UK plasterboard sheets are 2400 × 1200mm (2.88 m²). Door openings are deducted from the wall area before calculating sheets.

Fixings and tape

Screws: 32 per sheet at 150mm edge / 300mm field centres
Scrim tape: Based on total joint length; 90m per roll

Standards

Stud walls should comply with BS 5268-2 (timber frame construction) and plasterboard installation with BS 8212. Fire resistance may require additional measures per Approved Document B.

Frequently Asked Questions

Last updated: February 2026

All calculations are estimates. Verify with your supplier.

Stud Wall Calculator

How We Calculate This

Stud calculation

Noggings

Plasterboard

Fixings and tape

Standards

Frequently Asked Questions

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