Monitoring Mass Timber Performance in the Irish Climate

Opening Context Mass engineered timber (MET) can help Ireland meet its climate commitments and support the European Union’s growing focus on reducing whole-life carbon emissions from buildings, but confidence in wider use depends on evidence of reliable long-term performance. Products such as cross-laminated timber (CLT) and glued-laminated timber (glulam) meet structural requirements and offer lower-carbon alternatives to concrete and steel. The next challenge is to demonstrate how completed buildings perform over time under different climatic conditions. This is especially relevant in Ireland, where humidity, wind-driven rain and limited drying periods create challenging conditions for timber structures. Once occupied, many timber elements are concealed and cannot be inspected routinely. Our research uses continuous structural health monitoring to verify that buildings are performing as designed, reassure clients and provide robust data on performance under Irish conditions for the wider sector. The same system can also identify sustained increases in moisture, allowing potential issues to be investigated early. Research Overview Presented by former ATU colleague, Dr Samar Momin, at the Civil Engineering Research in Ireland Conference 2026 in Belfast, the work combines practical sensor placement and data management into a single framework. Moisture and temperature sensors can be installed at different depths within mass timber elements, while a moisture detection grid can monitor areas that are normally hidden from view, such as roofs and floors. Indoor conditions and weather data are also monitored to help understand how factors such as ventilation, occupancy and changing weather affect the mass timber elements over time. A Timber-Structural Health Monitoring Suitability Index (T-SHMSI) was also developed to identify the most appropriate monitoring locations, considering factors such as moisture exposure, structural importance and accessibility. Tests were conducted at the University of Galway using a five-layer timber panel monitored for 250 days under controlled climatic conditions. The sensing approach is now being used in case-study buildings to examine how mass timber structures perform over the longer term. Key Insights / Findings Two points are central. First, the framework is designed to build a long-term evidence base for mass timber performance in Ireland. Data from moisture, temperature and indoor-environment sensors can demonstrate that timber elements remain within expected conditions when buildings are designed, detailed and constructed appropriately by experienced professionals. This gives clients a clear record of performance and provides the wider industry with evidence from buildings in use. Second, the laboratory experiment tested and confirmed the effectiveness of the sensing method before it was used in buildings. Under controlled humidity conditions, sensors installed at different depths responded in sequence as moisture moved through the mass timber panel, showing that the system could detect changes within the panels over time. The monitoring framework can then compare data from buildings with weather, ventilation and building-use conditions and identify any unexpected, sustained changes that may require further investigation. Why It Matters (Impact & Relevance) The main value of monitoring is reassurance. Clients, designers and contractors gain an objective record showing whether the timber structure is performing as intended under Irish weather conditions and normal building use. This evidence can demonstrate the success of well-designed mass timber projects, address concerns about a relatively unfamiliar construction system and support more confident adoption across the industry. Long-term data can also help professionals refine design details, construction practices and maintenance planning by showing which approaches deliver stable performance. Early warning remains a secondary benefit. If the monitoring system detects consistently high moisture levels, the facilities team can check the relevant location before a potential issue develops further. The framework therefore provides evidence of long-term performance while allowing for targeted intervention where necessary. It can also contribute valuable evidence to inform industry guidance, standards and public-sector decision-making. Wider Context / Application / Next Steps The framework is designed for mass timber buildings, with the number and position of sensors adjusted to each building's exposure, use and specific conditions. The next stage is long-term monitoring that compares indoor measurements with rainfall, humidity and wind. A web-based dashboard can present seasonal trends, allowing clients and the wider industry to see how the building performs over time. Automated quality checks will help ensure that the monitoring system and data are working as intended. If consistently high moisture levels are detected, a traffic-light notification can prompt a targeted review of the relevant area. Future work will also monitor how the mass timber panels move relatively over time alongside changes in moisture levels. The recorded data will support computer-based modelling of performance under different climatic conditions, helping to further develop and optimise mass timber systems for use in Ireland.