PUTTING ‘CELCURISED TIMBER’ IN ITS RIGHTFUL SPOT, USE AND CLASS
Timber has been a primary resource for fencing and landscaping for a number of years.
Affordable, natural, and aesthetically pleasing, it’s clear to see where its popularity comes from. However, timber’s reputation faces a constant threat from one key factor: inadequate treatment.
Managing the risk with adequate knowledge
Throughout the supply chain, there is a common knowledge gap when it comes to timber treatment. Is all wood fit for all Use Classes? Does the same treatment work in all scenarios? Are post-installation treatments enough to sustain wood for longer and keep it healthy? Here’s the short answer – no. Timber isn’t a one-size-fits-all solution – it falls into different Use Classes
based on where it is placed in the project and what role it’s performing.
This is heavily dependent on the type of wood and the treatment it is subjected to. When timber is treated, the purpose is to protect against specific threats, which differ based on location, weather conditions and application. This isn’t a nice to have – it’s essential.
Functional knowledge of the Use Classes is critical to the performance of timber. Without it, there is an increased risk of timber structures that are not fit for use and even pose a threat to health and safety. Use Classes are the guardrails for creating a safe and sustainable structure.
Using the Use Classes
Applications for treated timber are generally split into three main Use Classes based on their use: 2, for interior applications, 3 for exterior over ground uses and 4 for exterior ground contact applications. These classes determine the required treatment for adequate protection against moisture, moulding, fungal infestation and decay. In the context of fencing, any timber installed outside must be pressure treated to a minimum of Use Class 3 and Use Class 4 if in direct contact with the ground.
Use Class 3 incorporates treated timber recommended for external applications where frequent moisture exposure occurs without direct ground contact. Use Class 4 is the toughest category of treated timber. It is intended for scenarios where the wood is either in direct contact with the ground, consistently exposed to freshwater, or used for external structural support. This class is particularly used for posts for fences, the foundational structures of decks, walls that retain soil, garden beds, and structural components of bridges.
Proper treatment of timber within Use Class 4 is important, as outlined by the BS8417 standard, as it is responsible for the most crucial aspects of any structure and is subject to the most amount of wear and tear. In Use Class 4 scenarios, improperly treated wood is at significant risk, with potentially severe implications like structural damage, collapse and pest infestation.
Reinforcing UC3 and UC4 with Celcure
Kopper’s Celcure is a water-based copper preservative system with additional co-biocides that provides long term protection for timber exposed in interior and exterior applications. Celcure is pressuretreated to force the preservative deep into the wood structure, providing protection to the core.
Timber treated using this system is effective in all Use Class applications from Use Class 2 to Use Class 4. However, Celcure preservatives are best suited to Use Class 3 and Use Class 4 applications where the risk of fungal decay and deterioration due to external conditions is greatest. The term “Celcurised Timber” is widely used in the specification industry to denote timber treated with Celcure and is synonymous with external/outdoor applications.
Treating Use Class 3 with Celcure not only extends the lifespan of the timber but also safeguards the robustness and reliability of installations, further increasing its durability, safety, and performance. Using Celcurised timber for Use Class 4 cases ensures extended durability and structural integrity needed to overcome the greater risks.
Stronger for longer
Timber’s popularity as a fencing and construction material is increasing, and only pressure-treated products can help reach the desired benchmarks. Treaters, suppliers and merchants need to ensure that the right timber material undergoes the right treatment and is used in the right settings as per recommended Use Classes and industry standards. Treatments such as Celcure can add years to the use lives of fencing systems and building structures.
For more information, visit: www.kopperspc.eu
