fr.S. interest piqued in N ew Zealand-treated LVL

f, raw wooD rREArueNr that pro/a.tects laminated veneer lumber against both insects and decay-without compromising dimensional stability-is receiving serious attention from engineered wood manufacturers, wood treaters, and suppliers.

Azotek-which will be known as Taratek TC in the U.S.-was developed by Zelam Ltd., New Plymouth, New Zealand. The treatment has recently been included in the New Zealand building code as an acceptable solution for internal framing in residential and light commercial construction.

"This is a world-first," says marketing manager Noel Coxhead. "It essentially makes wet solvent treatments for LVL and plywood obsolete and opens the door to much wider use of LVL framing in building construction. It is difficult to get traditional treatments to penetrate the glue layers that bond the layers of LVL and plywood. The liquids involved also affect the dimensional stability of the finished product, which needs to be dried after treatment."

In contrast, application of Azotek takes place during manufacture, not after.

"The finished timber is dry and ready for use as soon as it rolls offthe production line," explains Coxhead. "Because the treatment compounds are present from the surface to the core of the timber, it can be drilled, sawn, and notched during building construction without any loss of integrity or need for retreatment."

In addition, traditional glue-line treatments protect against insects, but Azotek offers protection against both insects and decay-the first to do so, according to Coxhead.

Azotek-treated LVL has been available in New Zealand for more than a year. Its first commercial use was in the rebuilding of a cathedral in Christchurch, which was destroyed by a massive earthquake in 2011. Now known as the "Cardboard Cathedral" because of its innovative use of cardboard tubes, Azotek-treated LVL beams were used for the main structural elements.

"To my mind, Azotek is the best treatment on the market," says Andrew van Houtte, a sales engineer at Nelson Pine Industries. Nelson. New Zealand, which produces Azotek-treated beams, rafters, joists, lintels and bearers.

"In a technical sense, it is better than anything the industry has ever seen-exactly the right amount of chemical is applied and it penetrates throughout the product. It takes durability to a whole new level," he says. "It also has great environmental and health and safety credentials, because no heavy metals are involved in the treatment."

Coxhead says that the two fungicides in Azotek-triadimefon and cyproconazole-are widely used on food crops, but are new to wood treatment. Bifenthrin, a standard wood treatment insecticide, is also included in the formula.

"Finding suitable fungicides was a long journey for Zelam," he says. "We had many setbacks. Not only did the active ingredients have to be fit-for-purpose, they had to be readily available and affordable. Having two fungicides in the mix means it provides broad spectrum protection against rot and decay organisms, and a barrier against selection for resistance."

The LBM industry in Australia has shown much interest in Azotek-treated LVL, so field trials of treated LVL and plywood are now underway. "Our biggest market is driven by termites in Australia," says Andrew Thompson, Zelam' s general manager.

"But the bigger prize is likely to be the United States, where a lot of engineered wood is used in housing con- struction," adds Coxhead. "Already, wood processors there are showing a lot of interest."

DEEPER-PENETMTING treatment could ooen the door to oreater use of LVL framing in construction.

He explains thatZelam is conducting trials in Hawaiianother area with termite challenges, although with a different species than in Australia-testing the new treatment for the U.S. market.

"To supply the U.S. market, we need to complete a data set showing similar efficiency under local U.S. conditions," he says. "We have employed local consultants to assist us through this process, but we do not expect approval for another two years."

In the meantime, he adds, Zelam has received requests from U.S. suppliers "regarding New Zealand-treated product to complement the range of LVL products they are currently selling in the U.S. market."