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Cost-effective and accurate roof leak detection

Updated: Nov 10, 2023

Accurate roof leak detection is crucial for property owners, building managers and roofing contractors to prevent extensive water damage, reduce repair costs and maintain the structural durability of the property. Traditional methods of detecting leaks, such as visual inspections are often time-consuming and may not yield precise results. Fortunately, advancements in technology have introduced innovative solutions that offer both efficiency and accuracy.

With over 30 years of experience in the field of roof leak detection and building leak investigations, the high number of satisfied clients and prestigious contracts throughout the UK and Ireland, are testament to the exceptional level of service provided by Thornton Consulting. Our experienced team of field testers and consultants will employ various detection techniques as appropriate, following an initial evaluation of the roof area.

One effective testing method is the utilisation of electronic leak detection (ELD) of waterproofing membranes. There are two main techniques, but both rely on the same principal of the waterproofing membrane being an electrical insulator and the substrate beneath being an electrical conductor. Therefore, any breaches in the waterproofing can be detected where an electrical signal finds a path to earth.

  1. Low voltage “wet method”. A pulsed electrical signal is passed through the wet surface of the waterproofing membrane. A technician walks over the surface of the roof with a detector unit attached to two probes. Where a signal is located the detector unit indicates the direction of the breach which can then be located by homing in on the signal in a grid formation.

  2. Pinhole “holiday” method – A high voltage current is passed through a phosphor bronze brush which is swept across the surface of a dry roof. A breach is located when the signal finds a path to earth, alerting the techinican by an audible signal from the test equipment.

Both methods are highly accurate and locate breaches barely visible to the naked eye. ELD is also a non-destrcutve and cost-effective enabling testing of a roofs waterproofing in timely and efficient manner. Electronic leak detection is particularly useful as an integrity test for detecting breaches in newly installed waterproofing systems. Roofers and main contracters alike benefit from this service as it provides an assurance of the conditon of the waterproofing prior to hand over of the roof.

It is also a useful technique in building leak investigations, where it is important to establish the condtion of the waterproofing to locate the source of water ingress into a building. Its benefit is in either establishing the source of the leak as the waterproofing, or confirming that it is function satisfactorily so investigations can be targeted elsewhere.

Thornton Consulting takes a client-focused, comprehensive and systematic approach to the testing and location of breaches in the roof’s waterproofing material. Addressing existing leaks with an early resolution, or undertaking pro-active procedures to strengthen any identified weak areas, will extend the roof’s lifespan and preserve the overall integrity of the building, protecting your investment in the long-term.

If you would like further information on either test method for electronic leak detection, please contact our office on 01342 410508, or visit our website


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