Case studies – Leak Detection

Non-Destructive Leak Detection on a New School's Green Roof

A recently opened school building, completed in 2024, was experiencing persistent and disruptive leaks in its classrooms, offices and hallways. Although initial repair efforts had been carried out, the school required absolute certainty that the underlying issues were fully resolved and that the roof structure was completely watertight before the problem could recur.

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Polygon's Leak Detection team was contacted to conduct a thorough, non-destructive investigation. Our reputation for innovation and expertise in complex leak detection scenarios, particularly involving modern roofing systems, made us the ideal partner.

The Challenge: Testing a New Green Roof

The Green Roof features a thin layer of vegetation over a membrane and drainage system. This multi-layered structure is highly challenging for traditional, non-destructive leak detection.

The primary objectives were:

  1. Confirm the roof was fully secure and no longer leaking.

  2. Verify that water was draining correctly into the guttering system.

  3. Achieve all results using non-destructive testing methods to preserve the integrity of the new structure.

Polygon's Non-Destructive Solution

Stuart and his specialist Leak Detection team deployed a comprehensive range of advanced testing techniques to guarantee the roof's security:

Visual Inspection & Endoscopy

  • Purpose: Initial survey and internal checks of ceiling voids and pipes. 
  • Key Insight: Identified areas of potential water entry and confirmed access routes.

Flow Rate Testing & Spray Bars 

  • Purpose: Simulating heavy water flow to test the waterproofing layer and drainage. 
  • Key Insight: Confirmed water handling capacity and drainage efficacy.

Tracer Dye Testing 

  • Purpose: Introducing a coloured, non-toxic dye to trace the path of water ingress.
  • Key Insight: Crucial for following the water flow through the complex green roof layers.

Thermography 

  • Purpose: Using thermal imaging to detect subtle temperature differences caused by trapped moisture.
  • Key Insight: Pinpointed precise areas of moisture accumulation beneath the roof layers.

Advanced Flat Roof Survey

  • Purpose: State-of-the-art equipment for non-invasively mapping moisture content within the roof assembly.
  • Key Insight: Provided a final, definitive map of the roof's watertight status.

Future-Proofing: A Complete Digital Solution

The project Area Manager, Simon, recognised the opportunity to leverage more of Polygon's expertise. Following the successful leak detection and verification, he recommended deploying Polygon’s Climate & Digital Solutions team.

The proposed second phase involves installing advanced humidity and moisture sensors within the ceiling voids. This proactive step will provide the client with real-time, continuous monitoring. Any future spike in humidity or moisture levels will immediately indicate a potential leak, allowing the school to address issues at the earliest possible stage, long before visible damage occurs.

Conclusion: Polygon's One-Stop Approach

This project demonstrates Polygon's unique capability to offer a seamless, one-stop solution for building security and maintenance. By combining our industry-leading Non-Destructive Leak Detection with cutting-edge Climate & Digital Monitoring, we provided the school with not just a fix, but a guaranteed, long-term assurance of a dry and healthy learning environment.

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