Modeling Moisture Accumulation and Decay Potential in Cross-Laminated Timber Wall Assemblies Exposed During the Construction Phase

This study examines decay risks in cross-laminated timber (CLT) wall assemblies with built-in moisture, aiming to develop a simulation-based methodology to assess moisture dynamics during the construction phase. Differing from previous research, this study focuses on the central regions of CLT wall panels. Moisture distribution within the panel, especially in the exposed layer, is critical for understanding potential degradation. A series of simulations were conducted to determine the necessary level of detail for moisture profiling, comparing approaches that use a single average value, layer-specific averages, and a refined profile that distinguishes the outer 5 mm from the remaining material. The influence of factors such as wood type, glue type, delivery moisture content, orientation, and rain exposure was systematically evaluated to define realistic moisture profiles at the end of the construction phase. Subsequent degradation assessments incorporated these profiles along with variations in insulation materials to evaluate the time of wetness, dose accumulation, and heat flux increases. Results indicate that a detailed moisture profile is essential for accurately predicting decay risk and that trade-offs exist between moisture management and thermal performance depending on the insulation used. These findings provide a framework for predicting decay risks in CLT assemblies and offer insights for designing more durable and energy-efficient structures.