Field Study of Hygrothermal Performance of Cross‐Laminated Timber Wall Assemblies with Built‐In Moisture

Cross-laminated timber (CLT) panels have potential market in North America for building mid-rise structures due to their good structural and seismic performance, lightweight, and prefabricated nature. However, to ensure long-term durability, the hygrothermal performance of CLT wall assemblies needs to be evaluated in terms of drying and wetting potential before their widespread adoption in North America. A test wall was constructed with initially wetted CLT panels, and monitored over a year. The drying behaviour of the panels was analysed, and results were compared to hygrothermal simulations. It was found from the field data that no tested wall assemblies in the given climate prevented the panels from drying in enough time to prevent decay initiation. The hygrothermal simulation program is capable of predicting general trends, and can predict if a wall be safe, but tends to be overly conservative. Further refinement of the model for wood is needed.