What’s Electric Field Vector Mapping (EFVM?)
At ILD, we use a state of the art leak-detection method called EFVM. It's a low voltage test method that enables us to pinpoint defects in roofing membranes.
EFVM offers a more precise result than flood testing. By using EFVM, you’ll be able to locate your leak and repair it more effectively.
How does EFVM work?
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.
EFVM creates an electrical potential difference between a non-conductive membrane surface and a conductive substrate, which is earthed or grounded.
We apply water on the membrane surface and use it as a conductive medium. This creates an electric field.
Our EFVM technicians read the electric flow travelling across the membrane, enabling breaches to be mapped with pinpoint accuracy.
Concrete vs plywood:
Why the substrate of your building matters
Concrete vs plywood:
Why the substrate of your building matters
The substrate of your building will determine how we go about testing for leaks.
Membrane on plywood (non‐conductive substrate)
EFVM® requires (VMG™) Vector Mesh Grid between the plywood substrate and the membrane. If there is a breach in the membrane this will create a connection to the VMG™ beneath.
The VMG™ is a stainless steel grid that is a patented conductive medium when used with roofing/waterproofing systems that incorporate Electric Field Vector Mapping (EFVM®) leak detection systems.
Membrane on insulation (non‐conductive substrate)
EFVM® requires (VMG™) Vector Mesh Grid between the insulation and the membrane. If there is breach in the membrane this will create a connection to the VMG™ laid on top of the non‐conductive insulation.
Membrane on concrete (conductive substrate) - no mesh required
EFVM® electronic leak detection can be performed on the membrane application after the installation of the membrane. The concrete and reinforcing steel will create an electrical potential difference if there is a breach in the membrane.
