Treated Timber Joist 47 x 125mm C24
Treated Timber Joists provide a strong, durable, and versatile solution for a wide range of structural construction needs. Commonly known as softwood carcassing timber, these joists are graded to C24, meaning they deliver excellent strength, stability, and reliability for use in load-bearing applications across residential and commercial projects.
Each joist is pressure treated to enhance resistance against moisture, fungal decay, and insect attack, making it suitable for above-ground applications where there’s an occasional risk of wetting. The timber is planed and regularised, resulting in smooth surfaces, consistent section sizes, and eased edges for easy handling and a clean, professional finish.
These joists are kiln-dried to achieve a stable moisture content, improving both structural integrity and long-term performance by reducing the likelihood of twisting, warping, or splitting. Available in 3.0m, 3.6m, 4.2m, and 4.8m lengths, they are ideal for roofing, flooring, wall framing, decking frames, and general carcassing.
Responsibly sourced and PEFC 70% certified, these joists combine strength, sustainability, and ease of use — a reliable choice for any construction or renovation project.
Key Specifications
-
Section Size: 47 x 125mm
-
Finished Size (Approx.): 45 x 120mm
-
Lengths Available: 3.0m, 3.6m, 4.2m, 4.8m
-
Grade: C24 (Structural)
-
Treatment: Pressure Treated for protection and longevity
-
Finish: Planed and Regularised with Eased Edges
-
Moisture Content: Kiln Dried for improved stability
-
Certification: 70% PEFC Certified
FAQs
What is C24 timber used for?
C24 timber is a high-strength structural grade commonly used for load-bearing applications such as flooring joists, roof construction, and wall framing. It offers enhanced strength and fewer natural defects compared to lower grades like C16.
Can C24 treated timber be used outside?
Yes, C24 treated timber can be used outdoors where there’s an occasional risk of wetting, such as decking frames or external structural work. However, it should not be used in constant contact with the ground or water unless further treated.
Why are timber joists kiln-dried?
Kiln drying reduces the moisture content of the timber, improving its stability and preventing issues like twisting or cracking. It also ensures the preservative treatment penetrates effectively, extending the timber’s lifespan and maintaining structural reliability.
Check out our full range of timber.
Browse more timber lengths available online.
