Cross-Laminated Timber (CLT) is increasingly adopted in sustainable construction due to its structural performance and environmental benefits. However, its long-term durability under varying service conditions remains a concern. Therefore, this study aimed to investigate long term durability of CLT members through accelerated aging tests of small-scale specimens to simulate degradation of the member within a specified timeframe. The practical environment is simulated using experimental programs where CLT specimens will be subjected to cyclic wetting–drying, freeze–thaw. The elevated degradation-causing exposure will simulate moisture-induced swelling, thermal degradation, and adhesive deterioration to the CLT specimens. Mechanical properties, dimensional stability, and bond integrity will be evaluated before and after aging cycles to quantify performance loss and identify dominant degradation mechanisms. This experimental demonstration, conducted under an accelerated aging environment, will affect the material properties over time. The deterioration of the specimen will be studied to predict the long-term durability of the CLT specimens. The theoretical observation suggests that the degradation-based performance is linked to the service life of the specimen in the system. Therefore, the findings from the adhesive bond failure will be further studied to determine the effect on the service life of the CLT. This approach will enable the development of predictive models and performance-based durability assessment. Overall, the study contributes to improving reliability and sustainability in timber construction by integrating accelerated testing with service life modelling.