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Expert roofing and cladding solutions for commercial properties, delivered with precision and care.
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Proudly British Owned & Operated
Expert roofing and cladding solutions for commercial properties, delivered with precision and care.
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Proudly British Owned & Operated
Specialist commercial roofing tailored to the unique demands of your industry.
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Proudly British Owned & Operated
See how we've transformed commercial properties across London and the South East.
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Proudly British Owned & Operated
Non-invasive electronic leak detection for commercial flat roofs across London and the South East. We pinpoint the exact source of water ingress — no damage, no guesswork, no unnecessary disruption.
Leak Detection
Water ingress in a commercial building is rarely straightforward. The point where water appears inside is almost never where it's entering the roof. Without accurate leak detection, repair work is guesswork — and guesswork leads to repeat call-outs, wasted spend and ongoing damage.
Electronic leak detection uses specialist equipment to locate the exact point of water ingress through a flat roof membrane — without cutting, probing or causing additional damage to the roof. The process is non-invasive, highly accurate and significantly faster than traditional methods of elimination and investigation.
Exall Group provide electronic leak detection for commercial flat roofs across London, Essex, Surrey, Kent and Hertfordshire. We use low-voltage electrical field testing on single ply, built-up felt, liquid waterproofing and other membrane systems to identify breach points in the waterproofing layer precisely. Once the leak source is located, we can carry out the repair on the same visit or return to complete it as a scheduled works package.
Electronic leak detection is particularly effective on large flat roofs where visual inspection alone cannot identify the source, on roofs where a previous repair hasn't resolved the problem, and on new installations where a post-installation integrity test is required. It works alongside our condition surveys and drone surveys to give a complete picture of roof performance.
Our Process
We attend site and assess the roof type, membrane system and the reported area of water ingress. We confirm that electronic leak detection is the appropriate method and agree the scope of the test with you before starting.
The detection equipment is set up on the roof. For low-voltage electrical field testing, a low electrical charge is applied to the roof membrane. The system identifies any breaks in the membrane where water or moisture is present, allowing precise mapping of the breach location.
The equipment pinpoints the exact location of the leak — not just the general area, but the specific point of entry. We mark the location and document it with photographs for the report.
We produce a report confirming the leak location, the likely cause and our recommended repair. Where possible, repairs are carried out at the same visit. More complex repairs are quoted and scheduled separately.
Frequently Asked Questions
Electronic leak detection is a non-invasive method of locating water ingress points in flat roof membranes. It uses low-voltage electrical field testing to identify breaks in the waterproofing layer precisely, without cutting or probing the roof. It is significantly more accurate than visual inspection alone and avoids the damage caused by traditional investigative methods.
Electronic leak detection works on single ply membranes, built-up felt roofing, liquid waterproofing systems and other membrane-based flat roofs. It is not suitable for all roof types — we confirm suitability at the site assessment stage before proceeding.
No. The process is completely non-invasive. The low-voltage electrical field used in testing is harmless to the membrane and leaves no marks or damage. This is one of the main advantages over traditional investigative approaches.
In most cases yes. Once the leak source is identified, our team can carry out the repair on the same visit where the repair scope is straightforward. More complex repairs — failed laps, larger membrane failures or structural issues — are quoted and scheduled separately.
This is one of the most common situations we encounter. A repair to the wrong location will not resolve the problem. Electronic leak detection identifies the actual breach point in the membrane — which is often some distance from where the water presents internally. If a previous repair hasn't worked, this is the correct next step.
Yes. We cover the whole of London and the wider South East — including Essex, Surrey, Kent and Hertfordshire. Call 0800 255 0325 or use the contact form to book.
Tell us about your project and one of our commercial roofing specialists will get back to you within 24 hours.
