5x2 Timber C24 Regularised Sawn Joist 47x125mm

Our 5x2 C24 Timber Joists are made from high quality, responsibly sourced timber from PEFC certified materials and are kiln dried for straightness and strength and eased corners for smooth handling. Measuring 47x125mm in size (finished size approx 45x120mm) and available in lengths of 2.4m, 3m, 3.6m and 4.8m, they are an ideal timber for decking frames, rafters, and other internal projects.

• Kiln Dried for additional strength and durability
• PEFC Certified
• For use in interior projects
• Regularised for uniform size, with eased corners
• Graded to C24 strength grade
• Conforms to BS 4978 and EN 14081:2006

What is 5x2 Timber in mm?

Typically measured in inches, “5x2” refers to the size of the joist in inches which is 47x125mm in mm. However, the true size of 5x2 Timber in mm is slightly smaller, due to the fact that most of our structural timber is regularised, which involves machining a length down to a uniform width and thickness along the entire length. This means that the “finished” size can be a few mm smaller than 47x125mm, usually closer to 45mm x 120mm.

This slight difference is minimal and in the vast majority of projects will make no material difference to your project, and is typical when using 5x2 regularised timber joists.

What is 5x2 Timber Used For?

Though a less common size than our 4x2 Timber, 5x2 Timber has the benefits of a larger size, and when graded to C24 means it is a strong and sturdy timber ideal for use in roofing and flooring, as well as providing a sturdy base in decking frames. For outdoor use, it is advised to treat the timber for protection against moisture and pest damage. 

What is Regularised Timber?

Regularised timber refers to timber that has been mechanically processed to achieve consistent and uniform dimensions. This process involves machining the timber on all sides, ensuring that the timber has smooth and even surfaces with standardised dimensions throughout its length. Regularised timber is commonly used in construction to provide uniformity in structural components, such as joists, studs, and framing materials, allowing for easier assembly and ensuring a more precise fit in building projects.

What Does Kiln Dried Mean?

Kiln-dried refers to a process in which timber or wood is placed inside a kiln in order to reduce the moisture content of the wood to a specific level. The kiln provides controlled heat and airflow,for a faster and more uniform drying process, which helps to minimise issues such as warping, cracking, and fungal growth in the wood. 

What Lengths Do 5x2 C24 Timber Joists Come in?

Our 5x2 Timber joists are available in 2.4m, 3m, 3.6m, and 4.8m. We try to keep all of these lengths in stock wherever possible, but on occasions where stock levels or availability in your area is low, we may substitute for a longer length.

What Is C24 Timber?

C24 timber is one of a few grades of timber commonly used in the UK, assessed by their bend strength. C24 denotes a higher strength grade compared to C16 timber. The "C" signifies the type of wood (coniferous), while the number indicates its bend strength grading.

C24 timber is known for its superior strength and load-bearing capacity, making it suitable for more demanding structural applications. It is commonly used in construction projects that require timber with higher strength characteristics, such as in larger spans, heavy loads, or situations where increased structural resilience is necessary. C24 timber is often chosen for applications like roof trusses, beams, and other structural components where enhanced strength and durability are essential.

Do I Need to Treat 5x2 Timber?

It is advisable to opt for our treated 5x2 Timber Joists for any uses where they are likely to come into contact with moisture or pests.