Quick answer: The most common stud wall timber size in the UK is 38mm × 89mm (3x4 nominal) for non-load-bearing internal partitions, with 38mm × 140mm (3x6) used for thicker walls or where extra insulation depth is needed. We supply all UK standard stud sizes in C24-graded timber, kiln-dried and ready for site.
Stud wall timber forms the vertical frame inside internal partitions. It carries the plasterboard, holds insulation, and (in load-bearing walls) takes the floor or roof load above. Choosing the right size is mostly about wall thickness, height, and whether the wall is structural.
UK stud wall timber sizes
| Nominal size |
Finished size |
Typical use |
| 3x2 (75x47mm) |
72×47mm |
Heavy-duty structural studs, load-bearing partitions |
| 3x4 / 4x2 CLS |
38×89mm |
Standard non-load-bearing internal partitions — the most common UK stud |
| 3x6 CLS |
38×140mm |
Thicker walls, deeper insulation, soundproofed partitions |
| 4x2 (100x47mm) |
97×47mm |
Load-bearing internal walls, taller partitions over 2.7m |
| 6x2 (150x47mm) |
147×47mm |
Heavy load-bearing or external timber-framed walls |
Finished sizes follow BS EN 336 and account for the planing/regularising process. Always order by finished dimension, not nominal, when matching to drawings.
What size stud should I use?
Standard internal partition (non-load-bearing)
Use 38×89mm CLS studs at 400mm or 600mm centres. This is the default for dividing rooms in homes and offices. Easy to plasterboard, takes 90mm acoustic insulation, and matches standard 100mm internal door linings.
Bathroom or thicker walls
Use 38×89mm if the wall just carries pipework and insulation. Step up to 38×140mm if you need to fit a soil pipe, deeper acoustic insulation, or built-in cabinets.
Load-bearing internal walls
Use 47×100mm C24 as the minimum. For taller walls (over 2.7m) or anything carrying floor joists above, calculate the load and step up to 47×150mm or specify based on a structural engineer's drawings.
External or timber-framed walls
Use 47×100mm C24 minimum, often 47×150mm in modern timber-frame construction to allow for full insulation between studs. These need to be C24 graded (not C16) under UK building regulations.
Why C24 for stud walls?
We stock C24 only — and for stud walls that's the right call. C24 is 50% stronger than C16 in bending, has tighter restrictions on knots and warps, and stays straighter after install. That matters for stud walls because:
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Plasterboard finishes show every twist. A bowed stud telegraphs through the wall after a few months.
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Doors and windows need plumb openings. C24's better dimensional stability means linings stay square.
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Building regulations assume C24. For load-bearing and external timber-framed walls, C16 won't pass control.
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You can use fewer studs at wider centres. C24 at 600mm centres often replaces C16 at 400mm — saving timber and labour.
Read our full C24 vs C16 guide for the strength figures and span tables.
How many studs do I need?
For a standard partition with studs at 400mm centres:
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Wall length ÷ 0.4 + 1 = number of vertical studs
- A 4-metre wall needs 11 vertical studs (4 ÷ 0.4 + 1)
- Add a top plate, sole plate, and noggins (horizontal pieces between studs at mid-height)
Order 10% extra for cuts, mistakes, and the occasional warped piece. Our team can work out a full take-off if you send dimensions or drawings — call 01656 745959.
Buying stud wall timber from Nottage
All stock kiln-dried below 20% moisture content, regularised for consistent dimensions, and graded to C24. Trade pricing on bulk orders, fast delivery across South Wales and the South West, collection from our Bridgend yard.
For load-bearing or structural work, browse the full C24 graded timber range. For framing across walls, floors and roofs, see the construction timber collection.
