4x2 Treated Timber C24 Regularised Sawn Joist 47x100mm - 4.8m

Our 4x2 Treated Timber Joists, measuring 47x100mm (with a finished size approx 45x95mm), come in a length of 4.8m. Crafted from responsibly sourced, high-quality timber from FSC certified forests, these joists undergo kiln drying to enhance their straightness and strength. Additionally, they are treated to resist moisture and pests.

• For use in exterior and structural applications
• Regularised for uniform size, with eased corners
• Kiln Dried for additional strength and durability
• Conforms to BS 4978 and EN 14081:2006
• Graded to C24 strength grade
• FSC Certified Timber

What is 4x2 Timber in mm?

Usually specified in inches, the term "4x2" signifies the joist size, equivalent to 47 x 100mm in metric measurements. Through the regularisation process the timber is planed to achieve uniform dimensions, resulting in a "finished" size that is slightly smaller, typically around 45mm x 100mm, ensuring consistency throughout.

This minor difference is largely inconsequential and rarely impacts most projects, remaining consistent across 47x100, 4x2 regularised timber joists.

What are 4x2 C24 Timber Joists Used For?

Regularised 4x2 timber joists are widely used due to their strength, making them a popular choice in constructing decks, garden buildings, and applications in walls, roofs and floors of timber-frame structures. This size is one of the most commonly used timber joists.

What is Regularised Timber?

Our timber joists are almost always "regularised", meaning the lengths of timber undergo machine-finishing to attain a smooth texture and consistent dimensions throughout the joist's length. This process might slightly affect the final product's size by a few millimeters.  Most regularised timber joists are C16 and C24 grades.

What Does Kiln Dried Mean?

Kiln-dried timber undergoes a process where it's placed in kilns with consistent heat, effectively eliminating excess moisture from freshly cut boards. This process reduces weight, boosts strength and straightness, and enhances workability. Compared to the extended timeline of air-drying, kiln drying offers a quicker and more dependable method.

What Lengths Do 4x2 C24 Timber Joists Come in?

We offer both treated and untreated regularised 4x2 timber joists in various sizes: 2.4m, 3m, 3.6m, and 4.8m. While our goal is to keep all sizes in stock for delivery, there might be situations where we provide a longer length as an alternative due to delays or unavailability of specific sizes in your region.

What Does C24 Stand For?

In the UK, regularised timber is often classified into two grades: C16 or C24. The "C" signifies the wood type, which is Conifer. The numeric value indicates the bend strength, assessed based on factors like imperfections and presence of knots, with C24 being the stronger grade between the two.

Usually, C16 timber joists find application in wall and roofing tasks, whereas C24 is preferred for scenarios demanding notably high strength, particularly in roofing and flooring joists.

Do I Need Treated 4x2 Timber?

Choosing 4x2 treated timber is recommended for projects prone to moisture or pest issues. These timbers undergo pressure treatment, ensuring thorough penetration of the treatment into the wood, offering longer-lasting defence against rot and pests. This option is particularly well-suited for outdoor projects like decking, roofing, and similar projects.