- Public
- Education
- Flat roof
Ensuring Longevity: Moisture Monitoring for Copenhagen’s School Roofs
- Customer
- Byggeri København
- Location
- Denmark

At a glance
- Building type
- Multifunctional school roofs (kitchens, green space, solar)
- Stage
- Construction and long-term operation
- Primary moisture risk
- Water ingress through heavily used flat roofs
- Consultant/contractor
- COWI and NCC
- Outcome
- Rainwater ingress detected and assessed during construction
“It’s not if water comes in through the roof, it’s about when.”
Challenge
Tackling Moisture Risks of Multifunctional Roofs
The multifunctional roof design had multiple areas of use, including outdoor kitchens, green spaces, and solar panels. Previous projects faced expensive repairs due to undetected water ingress, making proactive moisture management critical. The building owner had a clear problem statement going into the collaboration with Tector:
“It’s not if water comes in through the roof, it’s about when” - Mads Alleslev, Byggeri København
With flat roofs, localising the source of water ingress can be highly complex and costly, especially when roof surfaces are heavily utilised.
Solution
Proactive Moisture Monitoring with Tector’s Sensor System
Through COWI’s introduction, Tector’s moisture monitoring system was selected for its ability to detect potential water ingress during both the construction and maintenance phases. The sensors were strategically placed in vulnerable roof areas - near penetrations, drains, and assemblies. The sensors are installed beneath the insulation layer, ensuring that if water infiltrates through the top membrane, it is quickly detected.
During construction, an uncovered assembly allowed rainwater to penetrate, highlighting the value of the sensors in identifying the breach. This real-time insight allowed the contractor, NCC, to assess the roof’s condition and determine whether drying was necessary before further work continued. Long-term, the system will provide continuous monitoring to detect and localise any future moisture issues, enabling prompt repairs and avoiding costly damage.
Impact
Tector Detects Moisture Ingress During Construction
The moisture monitoring system gave the project team early warnings of water ingress, saving both time and money. The sensors will continue to play a critical role in maintaining the roof’s integrity, especially as it endures daily use from students and staff. By identifying issues early, the municipality can avoid the potential of 100x costlier repairs and extend the life of the multifunctional roofs.
This case highlights the importance of early detection in moisture management, especially for complex, heavily-used roof structures. Planning a green or multifunctional roof? See how Tector supports building owners.

