5x2 Timber Treated C24

(12 Products)

5x2 treated timber (also referred to as 47x125) is a high-quality pressure-treated C24 graded timber which offers resistance to both insect and fungi attacks. We sell 47x125 timber in various lengths of 2.4m, 3m, 3.6m, 4.8m and 6m - all of which can be cut or sawn to length. 

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What Is 5x2 Timber? 

5x2 treated timber, referred to as 47x125 in metric measurements, is a premium-grade construction material renowned for its durability and strength. 

This timber has been meticulously pressure-treated and meets the C24 grading standards, ensuring it can withstand substantial loads and stresses. 

It is particularly designed for structural applications that require robust, long-lasting timber.

What Is 5x2 Timber Used For? 

  • Flooring
  • Roofing - rafters/joists in a loft floor
  • Walling
  • Decking joists - as it is able to bear heavier loads than ungraded timber (or that which is graded to a lower level such as C16.)
  • Carcassing timber in floor joists
  • Garden furniture and other outdoor projects 


5x2 Timber Benefits 

  • Preservative Treatment: Enhances durability and lifespan by protecting against pests and decay.
  • Kiln Drying: Removes excess moisture, preventing warping and enhancing structural stability.
  • Planed All Around: Provides eased edges for safer and more comfortable handling.
  • Smooth Finish: Through the planing process, imperfections are eliminated, resulting in timber that's perfect for visible and aesthetic applications in both furniture and building structures.
  • Premium Grading - C24:
    • Superior Quality: C24 timber offers a higher quality compared to C16 grade, suitable for more demanding projects.
    • Higher Load Support: Can accommodate greater weights and wider spans, providing more structural possibilities.
    • Selective Sourcing: Achieving C24 grade is exclusive to timber from regions with slower growth rates, which results in a tighter grain and superior structural properties.
  • Versatile Use: The combination of protective treatments and the C24 grade ensures the 5x2 timber is apt for a broad spectrum of indoor and outdoor applications.


5x2 Timber Sizing Explained

5x2 timber is most often measured in inches, which is an imperial measurement, though it is sometimes measured in metric and this is where millimetres (mm) come into play. 

The sizing of 5x2 timber is considered to be either:

  • Nominal Size: 47mm x 125mm
  • Finished Size: 45mm x 120mm


This slight discrepancy is accounted for by the way the timber is cut and prepared. The difference in the two sizes is minuscule and should not make a meaningful difference to your project. At Materials Market, we sell the finished size (45mm x 120mm).

Other sizes may be available so please get in touch if you require longer lengths.

5x2 Timber Treatment 

Tanalith E is applied to 3x2 timber through a process called pressure treatment. During this process, timber is placed in a closed cylinder, and the Tanalith E solution is forced into the wood under high pressure. 

This method ensures deep penetration of the preservative, providing long-lasting protection throughout the entire piece of timber.

Tanalith E is a popular type of wood preservative used in the treatment of timber. It's a water-based solution that includes copper and triazole compounds as active ingredients. This preservative is highly effective at protecting wood from fungal decay, wood rot, and wood-boring insects. 

Frequently Asked 5x2 Questions

What Is Regularised 5x2 Timber? 

Here at Materials Market, all our timber (including our 5x2 wood) is treated with preservatives, kiln dried, and then planed all round to give it eased edges that make for easy handling (regularised). 

Planing is a process in which the timber is sanded down to achieve a smooth finish, banishing imperfections and making it suitable for aesthetic use within a building or furniture building. 


What Is 5x2 C24 Timber? 

The term "C24 grade" is used to describe a higher timber quality than that of C16. 

C24 timber is a premium choice that can support higher loads and wider spans. 

Only timber imported from areas where the weather conditions demand a slower growth rate (and hence a tighter grain) achieves a C24 grade.

Thanks to the protective treatment and C24 grading of 5x2 treated timber, it is suitable for use in a variety of indoor and outdoor applications. 


Is It Possible To Paint 5x2 Treated Timber?

Yes, you can absolutely paint treated timber. However, it is a good idea to allow the wood to dry completely before adding any paint or primer to it. 

This can take up to a few weeks depending on the environmental conditions of the storage area. 

Heat and direct sunlight can cause the treated timber to warp instead of dry out and damper conditions can prolong the drying out period. 


What Are The Benefits of Using 5x2 Treated Timber? 

There is an abundance of timber types available on the market from sawn treated timber, untreated timber and sawn carcassing timber. 

No matter your project, it is essential to always use good quality treated timber as timber is usually located in places that are not easy to get to. This means we usually have no way of knowing if parts of the structure are under attack from insects or dampness.

With C24 graded timber, you won't need to pay mind to 'checking in' on the timber, as its pressure treatment renders it unaffected by both fungal and insect attack. Essentially meaning, it can fend for itself without you maintaining it. 

Here are just a handful of the benefits on offer with treated timber:  

  • It is treated to resist rot, decay and insect attacks
  • The most durable timber option, making it ideal for outdoor use
  • Thanks to its treated nature, treated timber is also low-maintenance
  • You won't have to spend time and money regularly maintaining it


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