Treated Timber Joist 47 x 175mm C24
Treated Timber Joists are a high-performance, reliable choice for structural construction work, offering strength, stability, and versatility. Commonly referred to as softwood carcassing timber, these joists are graded to C24, meaning they meet the highest structural standards and are suitable for load-bearing applications in both domestic and commercial builds.
Each joist is pressure treated to enhance its resistance against moisture, fungal decay, and insect attack — making it suitable for above-ground use where occasional wetting may occur. The timber is also planed and regularised, providing smooth, consistent section sizes with eased edges for easy handling and a professional finish.
These joists are kiln-dried to reduce moisture content and prevent warping or twisting, ensuring long-term stability and strength. Available in lengths ranging from 3.0m to 6.0m, they’re ideal for floors, walls, roofs, and general carcassing applications. With a PEFC 70% certification, this timber is responsibly sourced, ensuring sustainable forest management while maintaining exceptional quality.
Key Specifications
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Section Size: 47 x 175mm
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Finished Size (Approx.): 45 x 170mm
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Lengths Available: 3.0m, 3.6m, 4.2m, 4.8m, 6.0m
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Grade: C24 (Structural)
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Treatment: Pressure Treated for durability
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Finish: Planed and Regularised with Eased Edges
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Moisture Content: Kiln Dried for improved stability
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Certification: 70% PEFC Certified
FAQs
What does the C24 grade mean for timber joists?
C24 is a high structural grade that signifies superior strength and quality. It’s ideal for load-bearing applications such as floors, roofs, and walls, offering better stability and fewer natural defects than lower grades like C16.
Can treated timber joists be used outdoors?
Yes, C24 treated timber is suitable for external use where there’s an occasional risk of wetting. However, for timber in direct ground contact or constantly wet environments, a higher treatment specification is recommended.
Why is kiln drying important for structural timber?
Kiln drying lowers the timber’s moisture content, making it more stable and less prone to warping, cracking, or twisting. It also ensures the preservative treatment penetrates more effectively, extending the timber’s lifespan and reliability.
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