Durability Assessments of Wood-Frame Construction Using the Concept of Damage-Functions

Review of the state-of-the-art on fungal damage of wood materials showed that a combination of period of cumulative time when moisture and thermal regimes are above specified minimum is needed for fungal activities to cause biological decay in wood. The long-term performance of a typical wall assembly was evaluated using an existing computer model of heat, moisture, and air transfer in conjunction with a biological damage-function model. The hygrothermal behaviour and the associated biological damage were evaluated using virgin materials properties. The damage results are rather conservative because test results revealed that subsequent wetting and drying change the microstructure features of typical engineered wood products.