As the construction and infrastructure sectors strive for greater sustainability, the use of treated timber has become increasingly important. Modern wood preservatives not only extend the service life of timber but also play a crucial role in decarbonisation by locking carbon within durable wood products and reducing the need for frequent replacement. Among the leading solutions are Tanalith E, Tanasote, and Vacsol – each offering unique benefits and best-fit applications.
OUTDOOR TIMBER
Tanalith E is a water-based wood preservative containing copper and organic co-biocides. Designed as a multi-purpose wood preservative covering above and below ground applications UC1-UC4. It is widely used for high-risk applications, particularly where timber is exposed to the elements or in ground contact (Use Class 4).
Its versatility makes it suitable for fencing, decking, landscaping timbers, and agricultural structures. The copper-based formulation provides robust protection against decay fungi and insect attack, ensuring a long service life even in challenging environments.
One of the key sustainability advantages of Tanalith E is its contribution to the circular economy. Modern formulations use just the right amount of copper, paired with powerful organic co-biocides, which helps with waste classification at end-of-life and reduces environmental impact. With comprehensive Environmental Product Declarations (EPDs) and Life Cycle Analysis (LCA) data available, specifiers can make informed choices about the carbon footprint of their projects.
HEAVY-DUTY APPLICATIONS
Tanasote is an advanced oil-based wood preservative, developed as a high-performance alternative to creosote. It is particularly suited for industrial applications such as utility poles, railway sleepers, and long-term agricultural fencing. The formulation of Tanasote combines copper with powerful cobiocides, offering broad-spectrum protection and a service life of up to 50 years.
The durability of Tanasote treated timber means carbon is locked in for decades, supporting decarbonisation goals. Independent testing and field trials have demonstrated its resistance to decay, water repellency, and compatibility with sensitive environments. Tanasote is also the only modern oil-based preservative that is approved via a full evaluation under EU Biocidal Products Regulation (BPR) and is recognised under national schemes such as NTR and CTB P+. Its long service life and low environmental impact, as confirmed by LCA studies, make it a preferred choice for infrastructure investments.
INTERNAL USE
Vacsol is a low-pressure, metal-free, and VOC-free water-based preservative, ideal for internal joinery, timber frames, roofing battens, and wood windows (when topcoated). Vacsol 6118, the latest formulation, provides up to 60 years of protection when applied correctly. Its metal-free composition allows treated timber to be recycled or reused at end-of-life, promoting circularity in the built environment.
The concentrate format of Vacsol also reduces embodied carbon in transportation, further enhancing its sustainability credentials. It is best used where timber is protected from direct weathering but still requires assurance of long-term durability and structural integrity.
QUALITY PRESERVATION AND LONG SERVICE LIFE
Quality preservation is essential for maintaining confidence in timber as a sustainable material. Poorly treated products can undermine the reputation of the industry and erode trust in wood’s environmental benefits. Rigorous testing, independent certification, and investment in EPD and LCA data are vital to ensure treated timber meets performance claims and delivers genuine sustainability.
By choosing the right preservative for each application – such as Tanalith E for outdoor and ground contact, Tanasote for heavy-duty infrastructure, and Vacsol for internal use – specifiers can maximise service life, reduce maintenance, and support decarbonisation.
Treated timber, when properly preserved, is a renewable, low-carbon solution that helps drive the transition to a more sustainable future.
