Abstract
This report presents the first integrated update on an in-situ monitoring and analysis programme that investigates how moisture influences the durability and structural performance of mass timber elements in a subtropical building at the University of the Sunshine Coast’s Moreton Bay Campus. The project combines long term field data from embedded OmniSense sensors with upcoming laboratory tests to build predictive models and practical guidance for designers, builders, and facilities teams. 46 sensors using both shallow and deep screws were installed across CLT walls and ceilings and GLT beams and columns with coverage on all principal orientations and at multiple depths. Three data gateways were deployed, and while connectivity interruptions created several gaps, most sensors now provide a robust and continuous dataset from late 2024 to August 2025 for building location specific interpretation.
Across the monitored period the timber remained dry and resilient. Moisture content typically sat between 7 and 15 percent and never entered the biological risk bracket. Three wet periods (including Cyclone Alfred) around 10 March, late March to early April, and late April to early May lifted indoor relative humidity and dew point for a few days, yet moisture content stayed comfortably low and returned to baseline quickly.
Moisture dynamics were governed by indoor vapour conditions rather than by liquid water. Dew point rarely approached surface temperatures and condensation risk was low. Orientation affected timing and amplitude rather than safety. West faces showed slightly larger afternoon vapour peaks and slower recovery. South facing areas were cooler and a little more humid than the north. Depth of screw penetration affected timber moisture content readings more than air side metrics. In general, deeper screws recorded slightly higher and slower changing moisture that reflects inner lamella behaviour, while shallow screws captured quicker surface responses.
Location specific checks confirmed these patterns. Ground level sensors near glazing remained below 20 % and re-stabilised within three to five days after rain. Level 1 positions beneath the cool and freezer rooms showed small but coherent offsets, with the cool room side marginally cooler, more humid, and about 0.7 % higher in mean moisture. Level two beams along the south curtain wall were uniformly dry and stable. Corridor sensors showed the south side a little more humid and the end wall position the driest. No location showed evidence of liquid water ingress or sustained wetting.
The project now moves to strengthen coverage and deepen analysis. Priority actions are to restore all offline sensors and installed one additional gateway to enhance the signal coverage, maintain a daily health check on batteries and connectivity, and consider an onsite weather station to replace the 10 km proxy. The analysis plan will standardise correlation and lag studies and build event database for rain and humid periods. These steps will calibrate predictive models in the upcoming PhD programme and formalise alert thresholds, typical lags, and orientation and depth expectations. The expected outcome is a validated evidence base and practical recommendations that improve the moisture resilience of mass timber assemblies in Australian Southeast Queensland subtropical conditions and inform design and operational guidance for industry.