A two-year test evaluation conducted by coatings manufacturer Teknos UK Ltd has named Accoya as the best performing wood.
In March 2009 Teknos, in conjunction with Vincent Timber, devised a test to provide “real life” data on the performance of three of its coating systems on durable timbers western red cedar, Siberian larch, pine and Accoya, applied to differing cladding profiles and timber substrates.
Four separate test panels were used in the comparison. Each panel consisted of nine boards of the same profile, with three boards from each of the tested timber species.
Two panels were constructed using the VT10 profile, while two additional panels used the VT10B and the enhanced shiplap profiles. These two contained just one “cut” joint in each of the three timber species.
Each board was coated using the same application method. The Aqua Primer 2900 Teak was applied by dip application followed by a mid coat of Aquatop 2600 Cypruss Gloss. Once dry, a topcoat of Aquatop 2600 Cypruss Gloss was applied to the front face of each board.
All drying was carried out at ambient air temperature with air circulation provided by overhead ceiling fans. The backs of each panel were sealed using a sheet of 9mm plywood to protect the rear face of the boards.
After 25 months of being exposed to the Oxfordshire countryside, Vincent Timber inspected the panels.
Most panels showed signs of weathering of the coating, moisture ingress and cracks in the timber substrate.
“Accoya outperformed the other two timber species with very little evidence of being exposed for two years; no problems were recorded that could be associated with possible differential movement,” the report concluded.
