The nitty gritty on how electronic leak detection works.

At ILD, we use a leak detection method called EFVM.  It's a low voltage test method, which is more accurate than flood testing.


What's EFVM?

EFVM is a state of the art testing method that enables us to locate defects in roofing membranes. 

Sometimes these defects happen during or after installation – perhaps due to mechanical damage caused by others, or workmanship defects, material defects, design faults, weather related defects or membrane deterioration.

By using EFVM, you’ll be able to pinpoint your leak and repair it more effectively.

How does EFVM work?

EFVM creates an electrical potential difference between a non-conductive membrane surface and a conductive substrate, which is earthed or grounded.

By applying water on the membrane surface and using the water as a conductive medium, an electric field is created and a breach in the membrane creates a vector (ground fault connection).

Your EFVM technician then reads the electric flow travelling across the membrane, enabling breaches to be mapped with pinpoint accuracy.


Some nifty diagrams to explain this further.


This membrane is watertight ...

If the membrane is watertight, the electricity can't find a ground earth connection. In other words, there's no leak.


... this one is not.

If the membrane isn't watertight, the electricity makes a ground connection and is pulled towards the positive pole, effectively locating the leak.


Concrete vs plywood: 
Why the substrate of your building matters.

The substrate of your building will determine how we go about testing for leaks.


Non-conductive substrates

For non-conductive substrates such as plywood or insulated roofs, mesh is required. Your waterproofer or builder will need to lay the mesh before testing can happen.




Conductive substrates

For conductive substrates such as concrete, mesh isn’t required and testing can be completed after the membrane is installed.


What you can expect from your ILD report

Our fully trained and certified technicians complete the EFVM integrity test by conducting a visual inspection of all wall junctions, perimeter details and membrane penetrations, then providing CAD drawings, picture documentation and a written report detailing the locations of the breaches.