Back in 2020, the global climate change conference COP 26, cited construction activity as a major contributor to greenhouse gas emissions.

It also highlighted that using more sustainable materials, like wood, could reduce emissions significantly. Forward to 2023 and the environmental performance of construction products is still in the spotlight. Now there are smarter tools available to landscapers and manufacturers which measure the environmental footprint of products – not only carbon usage but life cycle assessment (LCA) too.

Responsible industries

By using such tools, Timber Development UK (TDUK) – the Wood Protection Association’s (WPA) affiliated trade partner – in collaboration with Energise, have assessed the carbon footprint of the UK timber industry.

The findings, published in the Net Zero Roadmap (January 2023), show the emissions of timber related industries in the UK are responsible for just 0.35% of UK emissions. This is very low compared to other manufacturing industries. Statistics in the Roadmap show UK steel production is responsible for 2.7% of UK emissions and concrete, 1.5% of UK emissions. The publication presents a Net Zero emissions pathway for the Timber Industry to achieve by 2050, alongside a set of high-level policy recommendations and sector action plans to deliver the reductions.

By any measure of sustainability, wood scores highly; managed properly, trees provide a renewable material that absorbs and stores (sequesters) carbon. At the end of its life wood can be reused in a cascading process of uses, recycling or recovery of energy. The same cannot currently be said for many other construction materials, including the increasingly popular wood plastic composite (wpc) products. Although some are recycling waste plastics in their product formulations, this plastic cannot be recycled further and only a handful of manufacturers are offering to take it back once the consumer no longer wants it. It is an issue which may become more apparent in the next 10 years or so.

Enhancing durability with developing technologies

The main softwood species used for building and landscaping applications (Pine, Spruce) are generally not as durable asslow growing, more expensive hardwoods. To protect against fungal decay and insect attack, such timber components can be enhanced with industrial preservative treatments or wood modification processes. Pretreatment allows the use of the more perishable (sapwood) andnon-durable parts of a tree where they might otherwise be discarded or have a short service life.

The additional energy input of pre-treatment is comparatively low – there is research driven evidence to support this. And in terms of the ‘chemical’ aspect of treatment, the industry is highly regulated and continues to develop products and processes which are better targeted towards the organisms we wish to control and which have less impact on the wider environment.

Fit for purpose

Timber is particularly suited to fencing and outdoor structural applications – it’s easily worked on-site and treated and installed properly will last for its desired lifetime. Current results from the WPA long-term field trial of timber fenceposts (controlled by BRE) are showing properly treated wood can be trusted in outdoor applications. But, like any other construction material, treated wood must be correctly specified to ensure its performance. Market research by the WPA has highlighted misconceptions about treated wood products: in particular, that all treated wood has the same level of protection and can be used anywhere – which is not the case. British Standards require the level of protection is tailored to the component’s end use – via the Use Class system. Timber for in-ground, wet conditions needs higher protection than wood used indoors. The research resulted in many timber trade bodies working together to improve buyer and supplier knowledge.

Find a trusted timber supplier

Nowhere is the fitness for purpose of treated wood more important than for ground contact applications. The WPA continues to promote the ground rules to help ensure treated wood supplied for fence post applications is fit for purpose. First and foremost, make sure the supplier knows the timber is for a Use Class 4 application; secondly, make sure the wood is treated by a process certificated under an independent quality scheme such as WPA Benchmark. And finally, remember that high performance materials do cost more.

For further information and downloadable resources visit:

Ben Walton