The potential of moisture content measurements for testing the durability of timber products

Traditionally, the durability of timber is determined in laboratory decay tests or ground contact field tests. Since it is commonly accepted that results from those tests are not directly transferable to less severe above-ground exposures, this study aimed at assessing alternative durability measures related to the moisture performance of wood. Results from above-ground tests including continuous wood moisture monitoring were analyzed. Decay ratings determined in double-layer field tests were compared with time of wetness, and temperature- and moisture-induced dose according to a dose–response model for above-ground decay. Significant differences between European wood species were found in façade, decking, sandwich, lap-joint, and double-layer tests with respect to their moisture performance. It is concluded that for many wood-based products intended for above-ground use, a combination of short-term laboratory decay tests and mid-term moisture performance field tests may serve as time-saving alternative to long-term decay tests in the field.