A practical guide to moisture for timber construction
Moisture is one of the greatest risks to timber construction, but it’s also one of the most manageable. This practical guide, developed by the Danish Technological Institute and funded by Built by Nature, offers a comprehensive, experience-based framework for managing moisture in timber buildings across all phases of construction and occupancy. The document is a step-by-step manual, with checklists, diagrams, and downloadable templates to support implementation, which draws on lessons from the Build-in-Wood Demonstrator in Denmark, a full-scale, open-access timber test building equipped with a digital twin and real-time moisture monitoring. Whether you are an architect, engineer, contractor, or building owner, this guide equips you with the tools and knowledge to prevent moisture-related damage, reduce delays, and extend the lifespan of timber structures.
What’s Inside the Guide
1. Understanding Timber & Moisture
- How timber interacts with humidity and water
- Key concepts: MC (Moisture Content), the percentage of water in timber relative to its dry weight. EMC (Equilibrium Moisture Content), the point at which timber has balanced its internal moisture with the surrounding environment. EMC varies depending on temperature and relative humidity (RH).
RH (Relative Humidity), the amount of water vapor in the air, expressed as a percentage of the maximum the air can hold at a given temperature. FSP (Fibre Saturation Point), the moisture level at which timber’s cell walls are fully saturated, but no free water exists in the cell cavities.
2. Risk Identification
- Common moisture sources and high-risk areas
- Effects on aesthetics, structure, and health
3. Pre-Construction Planning
- Developing a Moisture Management Plan (MMP)
- Construction scheduling, delivery logistics, and protective strategies
4. Construction Phase
- On-site implementation of the MMP
- Storage, monitoring, and response to water ingress
5. Post-Construction & Occupancy
- Long-term maintenance and moisture surveillance
- Use of sensors and contingency planning
6. Tools & Templates
- Moisture checklists, measurement protocols, and example MMPs (via QR code)
Key Takeaways
- Moisture risks are predictable and preventable. Most issues arise from poor planning, inadequate protection, or delayed response to water ingress.
- Moisture content (MC) is critical. Timber should remain below 16% MC during construction to avoid mould and decay.
- Design decisions matter. Vertical construction, just-in-time delivery, and protective membranes significantly reduce exposure.
- Monitoring is essential. Moisture meters, sensors, and regular inspections help detect issues early and avoid long-term damage.
- Team coordination is key. Clear roles, responsibilities, and communication across all project phases are vital for success
Download the full guide in this page.
