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Building Under Construction
Waterproofing Integrity  Testing


Detecting leaks across the UK 

Testing of newly installed roof waterproofing membranes and coverings 

Waterproofing integrity testing is for newly installed and existing roof membranes, and coverings to ensure it is free from breaches, which is particularly beneficial for roofers and contractors when completing a project and is often a requirement prior to hand over of a roof to a main contractor.

This test can also be undertaken at any point during project, giving peace of mind to all parties that the waterproofing is free from defects as sometimes damage can occur to roofs on busy building sites, plus identify any potential problems before finishes such as green roofs and paving are installed.

Electronic Leak Detection

Electronic Leak Detection

The process involves electronic leak detection of the waterproof covering and is typically undertaken by one of two methods, depending on the roof build-up and waterproofing to be tested.


The wet test method, also known as earth leak detection, low voltage testing or “Wet test” relies on the insulating properties of the membrane and electrically conductive properties of water and substrate beneath to be effective....


Also know as Holiday or Dry  Testing, this method is non-destructive and highly accurate, detecting pinholes barely visible to the naked eye and can save considerable amounts of time and water...

Both test methods rely on the electrically conductive properties of the substrate and insulating properties of the waterproofing for accurate detection of breaches and is suitable for most types of membranes.


The test can be undertaken to both horizontal and vertical waterproofing, ensuring the entire roof is tested.

In some circumstances, however, electronic testing is not possible. For example, EPDM membranes are electrically conductive, in which case Thornton Consulting may be able to offer our Differential Pressure Test, whereby air is drawn through surfactant over laps, thereby testing them for integrity. 

Building Under Construction
Tall Buildings

Differential Pressure Testing

Our Differential Pressure Testing of waterproofing membranes service was developed as an additional technique for roof leak detection when electronic testing is inappropriate or technically incorrect for a specific roof construction or membrane type, such as non-conductive timber deck or EPDM membrane.

It is a non-destructive test which works by reducing pressure on an area of waterproofing membrane within a vacuum chamber and by drawing air through a surfactant applied over membrane laps, we can test them for integrity.

As with other electronic test methods, Differential Pressure Testing has replaced the need for flood testing in many circumstances and provides an efficient and cost-effective solution for roof leak detection.

Differential Pressure Testing

Our Reports

A test report and marked up plan will be issued for each roof and test area completed and a Certificate of Waterproofing Integrity (CWI) issued at completion of the project.

Our Work

To find out more about Electronic Leak Detection and how we use it in our work read our case studies and blogs below.

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