Hygrothermal Performance Analysis of Wooden Basements under Critical Conditions

Basements are integral to contemporary building design, serving as foundational structures with diverse functions in residential and commercial constructions. The utilization of wood as a natural, economical, and CO2 storage material for basement construction significantly influences the future of construction, necessitating established concepts to guarantee sustainability, and foremost, avoid possible damages induced by moisture intrusion. This paper explores the hygrothermal performance of a wooden basement when subjected to severe indoor and outdoor climates and in the absence of pressuring groundwater. Using both 1D and 2D numerical simulations, this study conducts risk analyses for several cases to evaluate how the wooden basement behaves under critical conditions, such as moisture accumulation in the assembly due to air convection through a gap in the insulation layer, air leakage through the waterproofing membrane, and high-vapor pressure caused by the high moisture load in the indoor space. The thresholds are determined for the initial wood moisture and indoor relative humidity, under which supports are given for the use of wooden elements in the basement structures, exhibiting satisfactory performance and avoiding wood decay in the construction. Additionally, the impact of the waterproofing membrane on avoiding wood decay in the assembly is highlighted.