CLS Studwork Timber – C16 Kiln-Dried 3x2 & 4x2

Our CLS studwork timber is C16-graded, kiln-dried softwood with a planed finish and eased edges, available in 3x2 (38x63mm) and 4x2 (38x89mm) sizes and lengths from 2.4m to 4.8m. Manufactured to Canadian Lumber Standard (CLS) specifications for consistent sizing and stability, it is ideal for internal stud walls, partitions and roof framing, with a 3-5 working day lead time to mainland UK.

CLS Timber Sizes

CLS timber is sized to Canadian Lumber Standard, so the actual planed dimensions (38x63mm and 38x89mm) are slightly smaller than the nominal imperial size. The rounded corners and planed faces are standard CLS features.

Technical Specification

Common Uses

CLS studwork timber is widely used for internal stud wall framing, partition walls and door linings, roof trusses and loft framing, boxing in pipework, lightweight furniture framing and, when treated, sheltered structures such as sheds and fencing rails. Its consistent sizing and planed finish make it the standard choice for fast, accurate stud work.

C16 Grade and Kiln Drying

The C16 structural grade provides reliable strength for load-bearing applications, while kiln drying reduces moisture content to help prevent warping or shrinking after installation. The planed surfaces with eased edges allow safe handling and clean, accurate fitting.

Delivery Information

Lead times are currently 3-5 working days to mainland UK addresses. Longer lengths are bulky items, so suitable delivery access is required.

Frequently Asked Questions

What does C24 graded timber mean?
C24 is a structural strength grade under BS EN 338. The C stands for coniferous (softwood) and 24 refers to the characteristic bending strength in MPa. C24 is the standard grade specified for structural work in the UK — floor joists, roof rafters, lintels and load-bearing frames. It is stronger than C16, which is used for lighter-duty applications like studwork and non-structural framing.

What is the difference between sawn and CLS timber?
Sawn timber has rough-sawn faces and square edges — it is used for structural joists, rafters and frames where the surface finish does not matter. CLS (Canadian Lumber Standard) timber is planed all round with eased (rounded) edges, giving a consistent, smooth finish. CLS is the standard choice for internal stud walls, partitions and any application where a neat finish matters. CLS is typically C16 graded while structural sawn timber is usually C24.

What is pressure-treated timber?
Pressure-treated timber has been impregnated with preservative under high pressure in a vacuum vessel, forcing the treatment deep into the wood fibres. This protects against rot, fungal decay and insect attack, extending the service life to 15-25+ years depending on the exposure. All our sawn treated timber is pressure-treated for outdoor and structural use.

What lengths is sawn treated timber available in?
Our sawn treated timber is available in lengths from 2.4m to 4.8m depending on the section size. Standard lengths are 2.4m, 3.0m, 3.6m and 4.8m. Check the variant options on each product page for the specific lengths available for your chosen size.

What sizes of sawn timber are available?
We stock sawn treated timber from 2x2 (47x50mm) up to 10x2 (47x250mm), plus CLS studwork in 3x2 (38x63mm) and 4x2 (38x89mm). All sizes are given as nominal imperial dimensions with actual metric sizes in brackets. Sizes from 4x2 upwards are C24 graded for structural use; 2x2 and 3x2 are C16 graded.