Preservation orders

Premature fence post failures have held the attention of wood treatment manufacturers and timber treaters in the face of market demands for a solution. Blame is attributed variously and in combination to the end of CCA (chromated copper arsenate); increased use of home-grown species, which are more difficult to treat; poor quality treatment and installation; and a diminishing pool of experience and knowledge.

There is agreement, however, in the fact that while something has gone wrong somewhere across the supply chain, everyone has their part to play in turning the situation around.

Each of the big players in timber treatments - Lonza Wood Protection (formerly Arch Timber Protection), Osmose and BASF Wolman have launched or are about to launch new products, while new methods of treatment, such as the incising of fence posts, are coming onto the market, and some treatment companies are beefing up warranties. In addition there is widespread interest in a sector-wide scheme that would ensure standards.

"CCA worked. The new chemicals were different, the dosing could have been higher, it was used with wet spruce... there were all kinds of issues down to a lack of quality field testing data," said Richard Gulland, head of technical sales at BASF Wolman.

"In the UK we need to have an approval body that determines retentions rather than the chemical supplier themselves. We also need this body to ask for field test results from the supplier when they bring new products to the market - not just lab tests. I would also like to suggest that the market learns more about the importance of the co-biocides in each chemical as it is these elements that do all the work against the brown-rot fungi in the field."

Critical mass
While Mr Gulland points to the NTR scheme in Scandinavia, he, along with others, believes the new Wood Protection Association (WPA) Benchmark scheme has an important role to play. WPA director Steve Young said the scheme has now reached "critical mass".

"Wood preservatives do work when correctly treated to correctly prepared timber," he said. "The UK is the last major market for treated wood that has resisted a third-party quality assurance scheme and we hope the Benchmark will reverse that.

"What our two auditors discovered with the first 'volunteers' for the scheme was that 70% did not have the correct technical calibrations and 60% did not have the 'safe relationship' established well enough between the species, the end use, pre-treatment condition, the process being used and so on. So there must be considerable room for improvement in the rest of the industry."

There are now 12 companies with products accredited, including BSW Timber and Walford Timber for incised timber, and others are seeking to register. Mr Young said a revised website for the Benchmark scheme was about to be launched.

Since CCA and copper chrome were restricted in 2005, the predominant technology has been copper organics, with each supplier using various co-biocides. Most of the new products for ground contact treatments are enhanced versions of existing formulations. As one supplier lamented, the Biocidal Products Regulation (BPD) had reduced the palette of active ingredients available. Gordon Ewbank, commercial director of Osmose, added: "The process of getting clearance is now far more onerous, and the cost and the time involved horrendous."

Among the manufacturers with new products, BASF Wolman is testing Wolmanit CX-8 F, which has been formulated to better treat spruce for the UK market, while Lonza has launched Tanalith E 8000, also for home-grown species. It uses patent-pending BARamine to improve the penetration and distribution of the preservative into the timber, and improve performance against copper-tolerant brown rot fungi.

"The fencing market remains fairly buoyant and our new product Tanalith E 8000 is helping bring confidence back to all fencing markets," said a Lonza spokesperson. "It allows flexibility to the treater to use only one product without having to decide on various formulations or double stocking."

Osmose is introducing Celcure AC10, which Mr Ewbank described as a turbo-charged version of the existing Celcure brand. "There are three issues: one is the preparation of the timber and the treatment - and the WPA initiative is very important here; the desire to use spruce unprocessed, which is not easy to treat, but incising will make a big difference; and the chemicals," he said. "We are very happy with what we have been selling for ground contact treatment, but we understand there is a desire for something more."

Viance, whose main product is Permawood ACQ, is developing a new product for Europe aimed at overall protection rather than preservation using a new patented technology. Ecolife is pressure-treated with a non-metallic preservative system to protect against weathering as well as fungal decay and insect attack.

"We believe copper organics are a mature technology, having been in commercial use for over 25 years," said European region manager Tim Cashman. "The new Ecolife product is already in use in some countries and we are working to introduce it here in the UK as soon as the BPD registration process allows."

Osmose is introducing its Micronized technology across all its products in the UK. The system involves grinding copper into a suspension so small that it penetrates the wood, rather than dissolving the copper. This has been the predominant technology for Osmose in the US for some years, but MicroPro products have been available in Europe as a niche market and at a premium price. Mr Ewbank said they would now be cost-competitive with existing products.

Lonza said the recently introduced Tanalised Clear had been used to treat timbers for several projects, including a pedestrian bridge in the London Olympic Park. Two service treatment facilities are now fully operational for the product at Bond Timber in Cornwall, as well as Lonza's service treatment centre at Preston.

PTG Treatments, one of the largest service treatment providers, with seven sites, has invested heavily in recent years, including at Cumbernauld in Scotland where it has just installed a low-pressure plant (see pp24-25). The 10m-long double vacuum plant allows the company to offer a full range of preservation treatments from one location.

Pressure from Europe
From January, however, many small treatment plants will be under pressure from the European Industrial Emissions Directive, under which local authorities will license and police them for pollution control. While private sawmills will carry on, some of the small builders merchants and other on-site operations may find it difficult to uprate their treatment facilities and the likelihood is there may be some consolidation, said PTG managing director Neil Ryan.

"At Cumbernauld we want to create a super treatment site for Scotland, whereas Perth and Rosyth also handle timber off the ship. We have six-and-a-half acres where we have two high-pressure and one low-pressure plant, and we will add a fire retardant plant in the future. All the high pressure plants will be tilting plants to improve drainage."

The near future, one supplier said, is probably more about tinkering. "Innovation is driven by demand and legislation. I don't see anything on the horizon. Demand for homegrown spruce will grow rather than kiln-dried redwood. I think there will be tinkering around the edges of the formulations rather than changes in the active ingredients or processes."

Also there does not appear to be any rush into products for modified wood. "We have some projects out there, but my personal feeling is that there are a number of technologies that are very strong, but struggling to get market share, so for the time our priorities are elsewhere," said Mr Ewbank.