Pressure-treated softwood (UC4) fence posts are performing well in a landmark independent 10-year field trial, members of the Wood Protection Association (WPA) were told at the WPA annual conference in Leeds.
The event on May 8, attended by timber processors, treaters, wood preservative manufacturers, merchants and other stakeholders, saw 10-year data shared for the first time by BRE which is conducting the research for the WPA.
The BRE’s Dr Ed Suttie said three different UC4 wood preservatives systems and four softwood species are being used in the field trial, while a number of stakes are also untreated for comparison. Two field tests sites – in England and Scotland – contain 1,650 75x75mm fence posts for the trial.
Mr Suttie said a sample of 380 of the UC4 treated posts saw 16 of them failing after the 10-year mark – about 4%.
“It does not get better than this,” said Suttie. “This is real data.”
“Preservative treated posts are performing well. Product data builds confidence in the market and underpins BS8417 and Benchmark (the WPA’s quality approval scheme) as the tools. The WPA field trial could provide the European Recommended Service Life (RSL) for a treated wood post.”
Mr Suttie’s presentation provided a snapshot of the research, with a more detailed breakdown expected to be publicised in June. Interesting research data was also shared about untreated trial posts, with Scots pine outperforming other species – at least one untreated Scots pine post was still performing into its 10th year, though Mr Suttie cautioned about outliers that are always present in trials.
Mr Suttie said the next five years in the field trial would be important for being definitive with the data analysis.
WPA members were keen to see the data promoted to help the treated timber sector fight back against alternative products.
“This information shows that when treatment is done correctly, treated timber is fit-for-purpose,” said a member.
A big feature of this year’s WPA conference was the merchant’s perspective, with Gareth Nicholls of MKM Building Supplies sharing the company’s perspective on treated timber, including an 8% increase in the proportion of treated timber stocked by MKM in the past three years.
Paul Pennick of the h&b Buying Group highlighted the lack of clarity and understanding in the market on treated wood and Use Classes in particular, as well as the need for further education and industry collaboration to help ensure correct use of treated products for specific end uses.
Fredrik Westin, of the European Wood Protection Association shared on the future of treated wood in Europe: unlocking business potential through advocacy, while WPA chairman Steve Young outlined strategic priorities for the WPA, including lobbying of policymakers.
