Treated 4.8m Timber Joist 47 x 100mm C24
Treated Timber Joists are a high-performance, reliable choice for structural construction projects that demand both strength and stability. Commonly referred to as softwood carcassing timber, these joists are graded to C24, ensuring excellent load-bearing capability and long-lasting performance for use in a variety of building applications. Each joist is pressure treated to enhance protection against moisture, fungal decay, and insect attack — making it suitable for above-ground use where occasional wetting may occur. The timber is planed and regularised, giving it a smooth finish, consistent sizing, and eased edges that make it easier to handle and install. The wood is also kiln-dried, a process that reduces moisture content to ensure greater stability and strength while minimising the risk of twisting or warping over time. At 4.8 metres in length, this joist is ideal for applications such as flooring, roofing, decking, and general carcassing where precision and reliability are key. Sustainably sourced and PEFC 70% certified, this timber combines performance, sustainability, and versatility — trusted by both professional builders and DIY enthusiasts alike.
Key Specifications
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Section Size: 75 x 100mm
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Finished Size (Approx.): 72 x 95mm
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Length: 4.8m
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Grade: C24 (Structural)
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Treatment: Pressure Treated for protection and 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 C24 mean in timber grading?
C24 is a high structural grade that ensures excellent strength, durability, and minimal defects. It is ideal for load-bearing applications such as joists, roofing, flooring, and wall framing where reliability is essential.
Can C24 treated timber be used outdoors?
Yes, it can be used externally in areas that experience occasional wetting, such as decking subframes or outdoor structures. However, for timber in direct ground contact, a higher treatment class is recommended.
Why is kiln drying important for treated timber?
Kiln drying reduces the timber’s moisture content, increasing its strength and stability while preventing movement or warping. It also allows the preservative treatment to penetrate more deeply, extending the lifespan of the timber.
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