DALLAS, TX – Scion, formerly known as the New Zealand Forest Research Institute, conducted a five-year field test with Accoya wood and other wood species, treated and untreated, in accelerated decay chambers and exterior ground contact. The study concluded that Accoya wood is more durable than four of the most naturally durable species and CCA treated wood.
The five-year trial began in March of 2005 with a series of Accoya wood’s acetylated stakes and those from cypress, old-growth western red cedar, kwila, teak, CCA H3.2 and CCA H4 treated radiata pines. In addition, comparison tests against untreated pine and treated pine with alternative processes were also conducted.The testing is particularly relevant to these timber types as they are traditionally used for joinery, siding, decking and external beams.
A selection of samples was put into chambers designed to accelerate natural decay. The conditions in the chamber were maintained around 80.6 degrees Fahrenheit and 85% humidity to ensure maximum exposure to the kind of environment that can cause rot and decay. The stakes were removed, washed and inspected at three monthly intervals and returned to freshly prepared soil beds. Another set of samples was installed in Scion’s established test site for assessing the durability of natural, treated and modified woods.
Each Accoya wood stake was in good condition after the five-year test, showing no established decay and achieving a top score of 9.8 out of 10 on the durability assessment scale (Index of Condition). The stakes were clean below the ground line, with some minor weathering resulting in a gray color above the ground mark.
In comparison, untreated stakes had an average life span of just eleven months. The stakes treated with CCA H3.2 and H4 specification showed moderate to severe, and slight to moderate decay respectively. In the last 12 months, three of the C3.2 CCA treated stakes failed while the remaining stakes were in poor condition. Two of the H4 stakes also failed during this period. Cypress, old growth western red cedar, kwila and teak all performed well below Accoya wood’s results.
Manufactured by Accsys Technologies, Accoya wood undergoes an acetylation process, which alters the wood’s reaction with water by permanently replacing free hydroxyls within the wood with stable acetyl groups that will not bond with water. Acetyl groups are naturally present in all wood species, which means that nothing toxic is added into the wood. The altered cell structure of the wood makes it unrecognizable to insects as food, as well as increasing its strength and stability. Accoya wood carries a 50-year above-ground and 25-year below-ground warranty against rot and decay.
“We are very pleased with these test results, as it clearly shows Accoya outperforms 4 of the most durable species including teak,” said Chris Adair, director, business development manager with Accsys Technologies. “Accoya wood has always held Class 1 durability and this further validates our claims that Accoya is a leading sustainable, high-performance wood,” he added.
Accoya wood is available throughout North America through a network of independent distributors. For more information about Accoya wood visit Accoya.com.
Source: Accsys Technologies
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