4x2 C24 Pressure Treated Timber Joist (47x100mm) - 3.6m

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.

We offer a variety of structural and graded timber - from small 3x2 sizes to larger 8x2 timber. We also offer CLS Timber that is typically graded to C16. Our C16 and C24 timber is available in a range of lengths from 2.4m - 4.8m, most commonly 2.4m, 3m, 3.6m, 4.2m and 4.8m.

Regularised timber refers to timber that has been processed to achieve consistent dimensions and smooth surfaces. This processing typically involves trimming and planing the wood to standardized sizes and shapes, ensuring uniformity in thickness, width, and length. This often results in the timber being a few mm smaller in width and thickness than their "official" size, but is so minimal that it is likely to have no impact on the large majority of projects.

Timber that is kiln dried is  placed in kilns where a consistent heat removes excess moisture from freshly cut boards, reducing weight, enhances strength and straightness, and improves its workability. Rather than using an air-drying process that can take several months to a year, kiln drying is a faster and more reliable method.