The effect of artificial ageing on the durability of wood-based board materials against basidiomycete decay fungi

In the biological testing of wood based board materials it has been demonstrated that the exposure of boards in a closed vessel system may lead to inaccurate results due to the build-up of volatile substances that inhibit the test fungi. It is assumed that this is a transitory effect of freshly manufactured boards. Our results with the European standard for testing the fungal durability of board materials, which is currently under development (ENV 12038:1996), confirm that this inhibition has a significant effect on the reliability of the durability results obtained. In the standard, a leaching procedure is used as part of a preconditioning method to remove this effect. Several factors suggest that leaching may not be the most appropriate method for this task. Therefore, a variety of alternative ageing procedures were studied, including natural weathering, leaching and evaporative procedures, to determine the most appropriate preconditioning protocol for the decay test. The results show that non leaching procedures can be more efficient, and possibly more meaningful, than leaching for use on board specimens.