This year’s WPA Wood Protection Industry Awards and Conference took place at the Windmill Hotel, Coventry on June 29-30.
“This ever popular two-day event goes from strength to strength,” said Gordon Ewbank, WPA director. “In uncertain trading times, it’s always good to remind ourselves that wood protection technologies help to make the most of wood as a modern, sustainable building material and to celebrate the very best design projects in the sector.”
And, introducing the speakers at the half-day conference following the Awards dinner the preceding evening (TTJ July/August 2022), Mr Ewbank said the presentations indicated “the collaborative approach” of the WPA in its partnerships with organisations such as Timber Development UK (TDUK) and the BRE.
The TDUK fielded two speakers – sustainability director Charlie Law and managing director David Hopkins. Mr Law’s presentation on the role of Environmental Product Declarations (EPD) arose from a discussion at last year’s conference when the wood protection sector was encouraged to become more involved in EPDs. Mr Ewbank highlighted that fact that the WPA had been proactive in that respect since then and had formed a working group headed by Neil Ryan, WPA regulatory affairs adviser.
Mr Law set out the drivers for EPDs, chief of which are the UK government’s now enshrined in law target to reach Net Zero Carbon by 2050 and its interim target of a 78% reduction by 2035 (compared to 1990 levels).
Mr Law pointed out that various organisations “within our value chain”, such as the Construction Leadership Council, World & UK Green Building Councils, RIBA, LETI (London Energy Transformation Initiative) and individual manufacturers and merchants had also set their own targets.
TDUK has also set net zero carbon targets and is supporting its members in halving greenhouse gas emissions intensity before 2030, said Mr Law, with a target of achieving net zero emissions before 2050.
He added that the targets were “very ambitious” but that progress is being made. “RIBA and LETI’s embodied carbon targets for buildings are stringent but they are being met in some projects,” he said, adding that the targets are voluntary at the moment but there are efforts to make them mandatory. Amendments to Part Z of the Building Regulations and the Embodied Carbon Bill are “going through at the moment”.
Mr Law pointed out that EPD ties in with the drive to the circular economy and extended building life. When reducing carbon over the whole life of a building there is a need to ensure the timber going into that building fulfils its life expectancy, he said. Wood preservative treatments have an obvious role to play in this.
Mr Law presented examples of an EPD and described the various stages of a lifecycle assessment/circular economy from the upfront carbon stage including raw material extraction, transport, production, manufacturing and construction; to embodied carbon during the building’s in-use phase; to operational carbon – water and energy; back to embodied carbon in the end of life stage, with deconstruction and demolition, transport, waste processing and disposal; to beyond the building lifecycle.
As well as ensuring an extended life expectancy of the timber in a building, Mr Law said it was important to keep developing technologies so that treated timber could be recycled for panel production at the end of a building’s life.
In terms of aims and objectives, the TDUK has brought together several organisations to create a net zero carbon roadmap and has appointed the Energise agency to launch the guidance at the end of the year. As part of the process, the TDUK ran a data collection workshop at the end of the WPA conference on June 30.
Dr Ed Suttie, director (research) at BRE also had a message about timber’s longevity in his presentation of the year seven performance results of the WPA field trial of preservative impregnated fence posts (TTJ July/August 2022).
The trial, which began in 2014, is based in two field sites with differing soil conditions – BRE Garston in Watford and Birnie Wood in Elgin – and provides “a bridge between what we know of performance in the lab against in the field….with real product data building confidence in the performance of wood,” said Dr Suttie.
There are 80 untreated posts and 600 treated posts (treated to Use Class 4 in accordance with WPA Benchmark quality criteria) installed at each of the two UK test sites. Matched samples of spruce (un-incised and incised), larch, Douglas fir and pine are being tested.
The BRE performance assessment of the timber after seven years has shown slightly different results from each site, but the overall outcomes are similar:
- Significant failure of untreated fence posts at both test sites
- No significant signs of change or deterioration in the inspected treated posts at either site
- In the case of incised and treated spruce, there were no signs of deterioration at either site
The seven year results are covered in more detail in the July/August edition of TTJ but, broadly, they show preservative treated posts performing well and, at the more aggressive site (Birnie Wood), signs that incised spruce is performing better than un-incised.
As well as presenting the results, Dr Suttie also highlighted the CLICKdesign project, which was introduced in 2019. The project sets out to deliver “fingertip knowledge to enable service life performance specification of wood” and is a collaboration between various international organisations as well as BRE, and an industry group.
The CLICKdesign project is developing a performance-based specification protocol to enable a software tool for architects, specifiers and the public to embed service life performance specification for wood. This will help increase market confidence with users for selecting wood as a reliable product and enhance an optimised performance of timber in the built environment.
Resources available via an app include modules on fungal decay, aesthetics, termite mapping, and structural integrity. They are all free of charge and for more information, visit https://bregroup.com/services/research/ clickdesign/
David Hopkins, TDUK managing director updated delegates on the merger between the Timber Trade Federation (TTF) and TRADA. He said that the process of combining two long-standing organisations with different management structures was taking time but was progressing well and that its aim of becoming “one supply chain, one vision, one organisation” and creating a direct connection between suppliers and specifiers would soon be achieved.
He also provided an update on the Preservative Treatment Action Plan and progress towards independent quality assurance of treatment processes. The Preservative Treatment Action Plan became part of the TTF Code of Conduct in 2020 and, as a result, members must adhere to the guidance provided in BS8417 (2014) and the 2021 WPA Code of Practice: Industrial Wood Preservation for the choice, use, and application of wood preservatives.
This means that members must ensure that:
Point A: Preservative treated wood is being accurately and unambiguously specified/ purchased, for use or resale, and is clearly identified on all points of the chain as fit for the intended purpose.
As a minimum this will require identification of the product as suitable for either:
- Interior use only – UC2
- Exterior use above ground – UC3
- Ground contact – UC4
Point B: Customers purchasing treated products from TTF members are provided with adequate information and, where appropriate, the training materials developed by TTF/WPA to be able to use and install those products safely and effectively.
Point C: Preservative treated wood is being produced by or purchased, directly or indirectly, from a treatment provider whose operation has been assessed and approved under an independent and reputable accreditation scheme (for example, the WPA Benchmark scheme in the UK, or the Nordic NTR scheme).
Points A and B were to be implemented by TTF members before the end of March 2021, while Point C was to be implemented before the end of June this year.
Mr Hopkins said the project’s aims for UC2 and UC3 pine products had been fully achieved and that those for UC4 were “close”.
“There is good understanding from members and customers but we need to complete all the audits and get the stragglers signed up,” he said.
“We also need to look at product marking for UC4 products, to make them more easily identifiable, and we need more installation and on-site education.”
UC3 spruce is where more work is required, he added. “There is a big grey area around what UC3 is, what the expected performance is and who will guarantee it, but there must be a way of overcoming that.
“If we want to sell the products we have to overcome these challenges and we can do that by working collaboratively together.”
The final speaker of the day, Callum Hill, of JCH Industrial Ecology Ltd played the role of devil’s advocate, posing the question, ‘Wood modification: hope or hype?’
Dr Hill recapped on the fundamentals of wood modification – that it involves a permanent change at cell wall level and that it provides protection against decay without biocidal mode of action; there are no problems with disposal at the end of life (for example, toxicity); it is fixed in the wood and not leachable; it adds dimensional stability.
Dr Hill said the advantages conferred on the timber following modification include the aforementioned improvement in dimensional stability (although there is still some movement) and fungal durability (depends on the type and extent of modification). In terms of whether it made the timber stronger, improved wear resistance and improved weathering resistance, he said there were still question marks.
He added that the quality of the starting material when modifying wood couldn’t be ignored – you can’t make a silk purse out of a sow’s ear – and that desirable properties for chemical or impregnation modification included highly permeable timber, sapwood, low knot density and straight(ish) grain. Radiata pine is commonly used.
Dr Hill also reminded delegates that wood modification comes at a cost and that there is a carbon penalty incurred during the modification process. So, he said, it was important to extend the life of the building in which the modified wood is used in order to make it cost and carbon efficient.
He also pointed out that the modified wood sector is still relatively small and that preservative treated timber would be used “for years to come”.
