5-year BRE inspection reveals all 1200 treated posts are standing strong
Untreated posts failing significantly
Copper organic preservatives work when applied correctly
A third of the way into the WPA’s 15-year field trial of softwood fence posts and some very interesting facts are emerging. The 5 Year Inspection carried out by BRE reveals that all 1,200 treated posts in the field trial are performing well and standing strong. The report also highlights that untreated posts installed at both the Watford and Elgin field trial sites are failing significantly. WPA Chief Executive Gordon Ewbank says that the facts emerging from the field trial are good news for the wood treating industry. He says: “Not that many years ago the performance of treated softwood fence posts was called into question. Back then anecdotal reports about premature failures and questions about the efficacy of wood preservatives were rife. BRE’s five year findings are a fair indication that treated wood in ground contact really can stand the test of time.” Gordon is quick to highlight the caveat to this statement which is the need to ensure that wood to be used in the ground or very close to the ground and frequently wet is correctly specified by the buyer and correctly processed by the treater.
Getting the specification and treatment right
British and European Standards group wood products into a series of end use applications called ‘Use Classes’. The Use Class tells a wood treater just how much preservative is required to protect timber in a specific end use – indoors or outdoors. Timber destined for contact with the ground or very close to the ground and frequently wet is in the Use Class 4 (UC4) category.
All 1,200 softwood posts in the field trial were treated to UC4 levels of protection. Their performance to date has given WPA the confidence to relaunch its ‘Make Sure it’s 4’ campaign which aims to help raising awareness about the need for timber for UC4 applications to be specified and treated correctly. Gordon Ewbank says the decision to focus on Use Classes in communications has been reinforced by a mystery shopping project the WPA carried out in June to help assess knowledge about UC4 treated wood in the supply chain. “This research has highlighted that knowledge about how to correctly specify and describe treated wood is not only extremely low, it is also undermining the opportunities to build confidence and grow demand for treated wood.” says Gordon, who confirms that improving supply chain knowledge and expertise is now a key priority for the WPA saying: “The ‘Make Sure it’s 4’ campaign is being brought back with a fresh new symbol to spearhead communications and we’ll be working in close collaboration with WPA members and the TTF and TDCA, our trade association partners, to help get the message over.”
Key facts from the 5-year inspection
In 2015 WPA contracted BRE to establish and monitor a large-scale field trial over 15 years. The aim was to provide an independent assessment of the durability performance of treated and untreated fence posts made from British sourced pine, Sitka spruce, Douglas fir and larch and determine if incising technology could benefit the permanence of these species in UK ground conditions. The overriding objective of the WPA and the industry sponsors who backed the project was to underpin lasting confidence in preservative treated British softwood fencing as a reliable and quality product. Two field trial sites were chosen with differing soil and exposure conditions. One at Watford and one at Elgin in Scotland.