Abstract
Mass timber elements have gained increased global interest as builders seek more carbon neutral materials. These products are primarily intended for interior uses where the risk of wetting is minimal. Moisture can have many detrimental effects on engineered wood products including swelling, cracking, delamination and, if prolonged, fungal decay. These products are manufactured using dry wood (<15 % depending on the product), but wetting can occur in between manufacturing and final building closure. Understanding the rates and degree of moisture intrusion can guide moisture management strategies to mitigate the risk of wetting and ensure performance. Water uptake was assessed over 24 days in Douglas-fir mass ply panels. Moisture contents exceeded 40 % in the upper four plies after 1 day of wetting but increased more slowly further inward. Prolonged wetting (24 days) resulted in moisture levels above 20 % deeper in the panel. The results highlight the speed with which wood moisture content can increase in MPP with rainfall and can be used to develop mitigation methods to minimise the risks of wetting.