Forintek Canada Corp. will assess the performance of hardwood and softwood treated blocks exposed to decay fungi. An evaluation of the potential of wood treated with copper thiocyanate, zinc thiocyanate, copper salicylate, zinc salicylate and zinc methylsiliconate for use in moderate or severe decay hazard conditions will be made. The work will be performed under Canadian Forestry Service contract 3-65-57-020.
Various treated commodities and simulated commodities have been put in test by Forintek Canada Corp. and its predecessors the Western and Eastern Forest Products Laboratories. This report draws together performance data on sawn-wood commodities pressure treated with CCA and pays particular attention to the relationship between preservative penetration and commodity performance. Non-incised, hem-fir decking with penetrations close to the proposed CSA 080, 2 inch decking standard has remained sound after 7 and 10 years exposure in British Columbia. Material which did not come close to this standard showed early signs of decay. In contrast, non-incised, finger-jointed SPF lumber samles have remained sound, despite very shallow preservative penetration, after 10 years above-ground exposure, possibly due to very low decay hazard conditions. In Ontario non-incised landscape ties made from sawn red pine have performed well over five years in test; hovever, even CCA-treated aspen-poplar peeler cores have performed well over this short time period.