Potential for decay in mass timber elements: A review of the risks and identifying possible solutions

Mass timber represents a range of composite materials, including glued- or nail-laminated timber, cross-laminated timber, laminated veneer lumber, and mass plywood panels that are increasingly used to construct multi-story structures. The potential of these wood materials has energized the architectural and engineering communities as they seek less energy-intensive building materials. However, performance optimization of mass timber buildings will require careful consideration of the potential effects of moisture intrusion on performance. This paper reviews the roles of moisture in building performance, discusses the potential effects of moisture on mass timber, outlines steps to limit moisture intrusion and, if this cannot be prevented, discusses possible steps for wood protection. The paper concludes with a call for further collaborative research to better understand the role of moisture in mass timber structural performance.