Morris, P. I. and Winandy, J. E.
2002 Thirty-third Annual Meeting of the International Research Group on Wood Preservation, May 12-17, Cardiff, South Wales, UK. Stockholm, Sweden
Morris, P. I. and Winandy, J. E., (2002), "Limiting conditions for decay in wood systems", Thirty-third Annual Meeting of the International Research Group on Wood Preservation, May 12-17, Cardiff, South Wales, UK. Stockholm, Sweden.
Abstract:
Description: Hygrothermal models can predict temperature and moisture conditions in wall components subjected to real weather data, but specific data and a fundamental understanding of how temperature and wood moisture content dictate the progression of decay under these conditions is required for modellers to predict consequences of decay on building performance. It is well understood that wood will decay above 30% moisture content and will not decay below 20% moisture content. Moisture contents between 20% and 30% represent a grey area. This paper describes cooperative work underway at our two Institutes to define limiting conditions of humidity/moisture and temperature that allow the initiation and progression of decay to diminish the structural performance of wood and wood composites as used in North American light-framed construction. Some preliminary results on time to initiation of decay in wood composites and moisture thresholds for wood materials under steady state environmental conditions are presented. Such a fundamental understanding of the limiting thresholds and eventual rates of decay above those thresholds is mandatory before legitimate models can be developed to predict the expected or residual serviceability of new or old building materials, respectively.
"Wood components within a wall would be expected to have considerably lower exposure to the air-spora unless there is a deficiency or opening in the fa?ade allowing them to enter the wall."
