8x2 Timber Treated C24
(14 Products)47mm x 200mm treated timber is a heavy-duty structural section designed to provide maximum load-bearing capacity and rigidity across large spans. Pressure-treated to ensure a high level of resistance against biological attack, these 8x2 lengths are a critical component for floor joists, flat roof systems, and substantial timber frameworks.
Understanding 8x2 Treated Timber
47mm x 200mm treated timber, traditionally known by the nominal 8x2 inch trade name, is a foundational element in professional construction. These sections are kiln-dried to achieve high dimensional stability and are strength-graded to C24 specifications. This grading ensures the timber possesses the density and structural integrity required for safety-critical applications where smaller sections would fail to meet span requirements or deflection limits.
The timber undergoes a high-pressure preservative treatment process, which forces protective chemicals deep into the sapwood. This treatment is essential for protecting the material from fungal decay and wood-boring insects, particularly in applications where the timber may be subject to moisture or poor ventilation.
With a finished size of approximately 45mm x 195mm, these lengths are regularised for consistency. The planed finish and eased edges allow for a high degree of accuracy when leveling floor planes and constructing plumb vertical frames, while also improving the safety and ergonomics for the installer on-site.
Material Range
- Individual 47mm x 200mm Lengths: Structural pressure-treated lengths available in a broad range of sizes from 2.4m up to 7.2m, providing flexibility for varied structural spans.
- Bulk 8x2 Timber Packs: Trade-scale 55-length packs designed for large-volume installations, providing a cost-effective supply for primary floor and roof structures (excludes 7.2m lengths).
Performance Benefits
- High-Grade Durability: Pressure-treated to resist rot and decay, ensuring the longevity of the building’s structural skeleton.
- Structural Performance: Kiln-dried and C24 graded to offer superior load-bearing capabilities and stiffness compared to standard domestic timber.
- Dimensional Accuracy: Regularised finishing ensures uniform depth and width across all lengths, which is critical for achieving flat, professional flooring and roofing finishes.
- Sustainably Sourced: Sourced from slow-grown timber to ensure a tighter grain and higher natural density for better screw holding and mechanical strength.
Typical Applications
- Primary Floor Joists: Supporting internal flooring across wide rooms and open-plan designs.
- Flat Roof Joists: Providing the deep profile necessary for supporting roof decks, insulation, and snow loads.
- Decking Substructures: Forming a heavy-duty, rot-resistant base for large elevated timber decks.
- Structural Framing: Building load-bearing external walls and heavy-duty internal partitions.
- Mezzanine Floors: Creating secondary floor levels in commercial and industrial settings.
Specification & Standards
- BS EN 14081-1: Strength graded structural timber with rectangular cross section.
- BS EN 335: Use classes of biological attack for wood-based products.
- BS EN 599-1: Efficacy of preventive wood preservatives.
Related Materials and Construction Uses
These 47mm x 200mm sections are the primary choice for installers who require high-specification structural wood that can withstand significant mechanical stress. In complex builds, these deep sections are often integrated with other specialist joist timber products to create a complete, high-performance structural system.
When installing these lengths, it is vital to use the correct heavy-duty hangers and fixings to maintain the integrity of the joints. Furthermore, any onsite cuts must be sealed with a suitable end-grain preservative to ensure the protective pressure-treatment envelope remains intact against the elements.
Frequently Asked 8x2 Questions
Is It Possible To Paint 8x2 Timber C24?
It's actually very easy to paint treated wood, but it's important to keep in mind that the wood should be allowed to completely dry out before any paint or primer is applied.
Be mindful of where you store the timber post its delivery, as too much heat or direct sunlight can cause the timber to warp rather than dry out. Conversely, damp conditions can lengthen the drying out period, prolonging the time before work can begin.
Am I Able To Cut Treated 8x2 Timber To My Preferred Size?
To cut treated 8x2 timber to size is a simple task, however, be sure to have all the appropriate power tools, eye protection, and a respirator to hand before cracking on, since the cutting process releases tiny airborne particles of wood, possibly impregnated with the chemicals used in pressure-treating.
Treated wood also cuts a little more like wet wood so some extra care should be afforded to ensure the blade doesn’t slip while cutting.
What Is The Difference Between 8x2 Treated Timber and 8x2 Sawn Timber?
Sawn timber is wood that has been cut to the required dimensions but hasn't yet been pressure treated and kiln dried. Pressure-treated timber, otherwise known as tanalised timber (due to the Tanalith E wood preservative that impregnates the wood) provides many benefits, such as resistance to the elements.
The goal of pressure treating wood is to force preservative chemicals deep into the timber's cellular structure. This pressure treatment process will often include copper and organic co-biocides, which help to repel both insects and moisture.
Please note: timber is a natural product that may vary in colour, visual details, knots, grain, and texture.
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