5x2 Timber

Frequently Asked Questions

What is 5x2 Timber Used for?

Our 5x2 timber is a versatile product with a variety of uses. Due to it’s strong C24 strength grading, it is often used in structural and framing applications such as in walls, ceilings and floors. It is also often used for outdoor structures such as pergolas and decking, when appropriate treatment is applied.

What Type of 5x2 Timber Do You Sell?

Our 5x2 timber is available untreated, in a range of lengths to suit your project. Our 5x2 timber is kiln dried and regularised for a smooth and straight finish. If you require a treated 5x2 timber, please be sure to get in touch with a member of our team, as it may be possible to source for you.

What Does C16 / C24 Stand For?

In the UK, regularised timber is most commonly classified into two grades: C16 or C24. The "C" signifies the wood type, specifically Conifer. The number (24/16) indicates the bend strength - which is based on factors such as imperfections and knots. While C24 is the stronger grade, C16 remains exceptionally strong and is used in numerous wall and roofing applications.

Do I Need Treated 5x2 Timber?

Untreated timber is most commonly used for interior projects where there is no risk of moisture. If your project is likely to come into contact with moisture, selecting a treated timber or further treating the timber yourself is recommended. Treated timber is often in practice preferred in interior projects such as framing and structural uses, as the pressure treatment helps defend against pests, and can be useful in event of leaks or moisture inside the building structure.

If you require 5x2 treated timber, please do contact us to check availability of stock.

Why Choose Our 5x2 Timber Range?

Our 5x2 timber (47mm x 125mm actual dimensions) represents the gold standard in structural softwood, carefully selected from sustainable European sources and processed to precise specifications. Each piece undergoes rigorous quality control to guarantee consistent dimensions, strength characteristics, and moisture content—critical factors that separate professional-grade timber from standard retail alternatives.

Kiln-Dried to Perfection: Every length is kiln-dried to 18-20% moisture content, significantly reducing the risk of warping, splitting, or dimensional instability after installation. This controlled drying process, combined with our regularised sizing, ensures your timber arrives ready for immediate use without the delays and complications associated with seasoning natural timber on-site.

C24 Strength Grading: Our timber carries C24 strength classification, providing bending strength of 24 N/mm² and modulus of elasticity values that exceed standard construction requirements. This superior grading makes our 5x2 timber ideal for structural applications where reliability cannot be compromised.

Treated and Untreated Options

Regularised Sawn Timber: Our standard 5x2 timber offers exceptional value for internal structural work. The smooth, consistent finish eliminates the time-consuming preparation work typically required with rough-sawn alternatives, allowing faster installation and superior finish quality.

Pressure-Treated Timber: For applications requiring enhanced durability, our pressure-treated 5x2 timber provides comprehensive protection against fungal decay and insect attack. Using advanced vacuum-pressure treatment processes, preservative penetrates deep into the timber structure, delivering long-term protection that surface treatments simply cannot match.

Applications and Technical Specifications

Our 5x2 timber excels in numerous applications where strength, stability, and dimensional accuracy are paramount:

Floor Joists: Spanning capabilities up to 4.8 metres for residential applications, with load-bearing calculations available through our technical support team
Roof Construction: Suitable for rafter and ceiling joist applications in accordance with BS 5268-2
Stud Work: Ideal for partition walls and framework construction requiring robust structural performance
General Framing: Perfect for workshop construction, outbuildings, and general carpentry projects

Available Lengths and Practical Considerations

We stock 5x2 timber in 3.6m and 4.8m lengths, the most commonly specified dimensions for residential and commercial construction. These lengths minimise waste whilst accommodating standard UK joist spacing requirements. For projects requiring different lengths, our cutting service can provide bespoke dimensions to your exact specifications.

Professional Advice: Our experienced team understands the complexities of timber selection and can provide guidance on span tables, load calculations, and building regulation compliance. From calculating joist centres to recommending appropriate hangers and fixings, we ensure your project benefits from genuine expertise.

Quality Assurance and Supply Chain Excellence

Every delivery from DIY Building Supplies reflects our commitment to quality and service. Our timber suppliers maintain FSC certification, ensuring environmental responsibility alongside technical performance. Each order is carefully selected, inspected, and packaged to arrive in perfect condition, ready for immediate use.

Nationwide Delivery: We deliver throughout mainland UK, with flexible scheduling to meet your project timeline. Our logistics network ensures your 5x2 timber arrives when you need it, properly protected and handled with the care quality timber deserves.

Trust DIY Building Supplies for your 5x2 timber requirements, where professional expertise meets competitive pricing, backed by the comprehensive support services that ensure your project's success.