Treated Timber Joist 47 x 225mm C24
Treated Timber Joists are a strong, reliable, and versatile choice for structural construction work. Also known as softwood carcassing timber, these joists are pressure-treated and strength-graded to C24, ensuring they meet the highest standards for use in demanding load-bearing applications.
Each joist is planed and regularised, creating smooth surfaces, eased edges, and consistent sizing for a professional finish and easier handling. The timber is kiln-dried, a process that reduces moisture content to a stable level, increasing both its strength and resistance to movement, shrinkage, or twisting over time.
These C24-graded joists can be safely used above ground in areas with occasional exposure to moisture, making them suitable for a wide range of structural projects such as flooring, roofing, wall framing, and general carcassing. Available in a variety of lengths from 3.0m to 6.0m, they offer flexibility for both small and large-scale builds.
Sourced responsibly and PEFC 70% certified, this timber not only delivers performance but also supports sustainable forestry practices — a trusted choice for professionals across the construction industry.
Key Specifications
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Section Size: 47 x 225mm
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Finished Size (Approx.): 45 x 220mm
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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 stability
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Certification: 70% PEFC Certified
FAQs
What does C24 mean in timber grading?
C24 is a structural strength grade that indicates superior quality timber, capable of withstanding higher loads and offering greater stability than lower grades such as C16. It’s ideal for demanding structural applications like floors, roofs, and joists.
Can C24 treated timber be used outdoors?
Yes, it can be used outdoors or in areas exposed to occasional wetting, provided it is properly treated and maintained. For long-term ground contact, use timber specifically rated for direct soil exposure.
Why is kiln drying important for timber joists?
Kiln drying removes excess moisture from the timber, reducing the risk of warping, splitting, and shrinkage. It ensures greater stability and strength, making the timber easier to work with and more durable over time.
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