Hygrothermal Analysis of Cross-Laminated Timber (CLT) in Canadian Climates With and Without Adhesive Layers Using a 1D-HAM Numerical Modelling Tool

Cross-laminated timber (CLT) construction in Canada is becoming increasingly popular, however, due to a lack of local mass timber building precedents and minimal hygrothermal testing and research, the durability of the product in Canadian climates is a source of concern. Current 1D HAM (heat, air, and moisture) modelling softwares used to analyze the hygrothermal performance of cross-laminated timber (CLT) do not account for the adhesive layers integral to the composition of CLT. The purpose of this study is to investigate the impact of adhesive layers on the moisture and air transfer in CLT through the use of a novel HAM 1D numerical modelling tool. The development and verification of the 1D HAM numerical modelling tool utilized for this study was completed by Vyas, et al. To further Vyas’ research, this study investigates the impact of adhesive layers on the hygrothermal performance of CLT in a range of Canadian climate conditions. The analytical model was used to test 3-layer and 5-layer CLT with and without adhesive layers in order to determine the impact of adhesive layers on the hygrothermal performance of CLT situated in Toronto, ON, Vancouver, BC, Calgary, AB, Yellowknife, NWT, and Halifax, NS. The results of the analysis show that the adhesive layers slow the rate of moisture transfer within the 3-layer and 5-layer CLT and that the direct exterior climate conditions do not have a significant impact on the hygrothermal performance of CLT in service when insulated on the exterior. The impact of adhesive layers on the long-term durability of CLT requires further validated through laboratory testing and long-term field testing.