4x2 Timber

Frequently Asked Questions

What is 4x2 Timber Used For?

4x2 Timber is a very popular size of Timber joist, and used for a variety of purposes, particularly decking and garden buildings, as well as in the construction of timber frame buildings.

What Types of 4x2 Timber Do You Offer?

We sell a selection of 4x2 structural timber - both treated and untreated, and also 4x2 CLS which is untreated and graded to C16. CLS timber has a slightly smaller profile than standard 4x2 timber joists, as it is regularised on all sides.

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.

What Does CLS Stand For?

CLS stands for “Canadian Lumber Standard” as it was originally sourced in Canada. Nowadays it is grown and sourced from various countries including grown here in the UK, but CLS is still used as a common name to identify the product. CLS is typically used for structural projects such as stud walls and partitioning, and is regularised on all sides, giving it a smaller profile than standard 3x2 timber by a few millimetres.

4x2 Timber Dimensions

If you are not familiar with timber sizing, the measurements of 4x2 timber may be confusing. "4x2" refers to the measurement in inches, the traditional way of measuring timber. This roughly translates to 47mmx100mm. However, in reality, most 4x2 structural timber is regularised to achieve a smooth and even surface along the length of the timber, which means that the dimensions are usually a few mm smaller - closer to 45mm x 95mm. Additionally, CLS Timber is finished on all sides which means it is a few mm smaller again - more like 38mm x 89mm.

Do I Need Treated 4x2 Timber?

Our Treated 4x2 Timber is treated to UC2 and is designed for use in outdoor construction, though timber in direct contact with moisture may need further treatment. Our CLS and untreated 4x2 timber is more typically used indoors in the construction of timber frame structures, although treated timber can also be used, as it simply gives it additional resistance to moisture and pests.

Why Choose Our 4x2 Timber Range?

Our 4x2 timber collection features meticulously graded softwood from leading UK suppliers, ensuring consistent quality and dimensional accuracy for your project. Whether you're constructing internal stud walls, creating roof frameworks, or building garden structures, our timber provides the structural integrity your build demands whilst maintaining the workability that makes installation straightforward.

Each piece undergoes rigorous quality control, meeting C24 structural grading standards that guarantee both strength and reliability. This attention to detail means you can proceed with confidence, knowing your materials will perform exactly as specified.

Versatile Applications for Every Project

Internal Framework: Perfect for creating robust internal stud walls, our 4x2 timber provides excellent structural support whilst remaining easy to work with standard tools. The precise dimensions ensure consistent spacing and alignment, making installation faster and more accurate.

Roof Construction: When building roof trusses or rafters, our structural-grade 4x2 timber offers the strength-to-weight ratio essential for long-term performance. The consistent moisture content prevents warping and ensures dimensional stability throughout the structure's lifespan.

Garden Buildings: From sheds to summer houses, our treated 4x2 options provide excellent resistance against moisture and insect damage, extending the life of your outdoor structures whilst maintaining their appearance.

Technical Excellence You Can Trust

Our 4x2 timber selection includes both treated and untreated options, allowing you to choose the perfect specification for your application. Treated varieties feature pressure-impregnated preservatives that provide long-term protection against rot and insect attack, making them ideal for external applications or areas prone to moisture.

For internal use, our kiln-dried untreated timber offers exceptional dimensional stability with moisture content consistently maintained below 20%. This careful preparation prevents shrinkage and movement after installation, ensuring your finished project maintains its precision and appearance.

Available Lengths and Specifications

We stock comprehensive length options from 2.4m through to 4.8m, accommodating both standard residential applications and larger commercial projects. Custom lengths are available upon request, ensuring you get exactly what your project requires without unnecessary waste or additional cutting.

All timber arrives with precise 100mm x 47mm finished dimensions (nominal 4x2), providing the structural capacity required for most building applications whilst remaining manageable for single-person handling where appropriate.

Professional Support When You Need It

Our technical team brings decades of combined experience in timber construction and can provide guidance on species selection, treatment options, and structural requirements. Whether you're planning a complex roof structure or a straightforward internal partition, we'll help ensure you specify the right materials for optimal performance.

From calculating quantities to advising on fixing methods, our expertise helps you avoid costly mistakes whilst ensuring your project meets all relevant building standards.

Quality Delivery Across the UK

Every order benefits from our reliable delivery network covering mainland UK, with careful handling ensuring your timber arrives in perfect condition. Our logistics team coordinates delivery timing to match your project schedule, reducing on-site storage requirements whilst keeping your build on track.

Ready to start your next project with confidence? Browse our complete 4x2 timber range or contact our expert team for personalised advice on your specific requirements.