Sawn Treated Timber 4x2 (47x100mm) – C24 Pressure-Treated Structural

Our 4x2 sawn treated timber has a nominal sawn size of 47 x 100mm and is supplied in C24 grade, pressure-treated softwood, in lengths from 2.4m to 4.8m. Ideal for load-bearing joists, structural spans and heavier construction, with a 3-5 working day lead time to mainland UK.

Technical Specification

Common Uses

4x2 sawn treated timber is widely used for load-bearing joists, structural spans and heavier construction, along with decking frames, fencing, sheds, raised beds, pergolas and general garden and construction projects.

C24 Strength Grade

C24 is a higher-strength structural grade with fewer knots and superior load-bearing performance, ideal for joists, rafters and structural spans where greater strength is required.

Pressure Treatment

This timber is pressure-treated with a deep preservative that helps protect against rot, insect attack and fungal decay, making it suitable for outdoor and exposed use. Treat freshly cut ends with a suitable end-grain preserver to maintain protection.

Finish

Supplied rough sawn for a natural, rustic finish. As a natural product, timber may show variation in colour, grain, knots and moisture content, which is normal for sawn treated softwood.

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.