No one catches leaks like ILD®. That’s why we’re the world leader.
ILD® IS THE WORLD LEADER IN ELECTRIC FIELD VECTOR MAPPING (EFVM®) TECHNOLOGY. WE CREATED IT. WE OWN IT.
EFVM® is a low-voltage leak test method that creates an electrical potential difference between a non-conductive membrane surface and conductive structural deck or substrate, which is earthed or grounded. EFVM® is unique in its ability to test the integrity of waterproofing membranes with overburden or ballast. This non-destructive method is important for green roofing systems because the EFVM® test can read through the overburden and ballast, while still providing perfectly accurate results.
HOW EFVM® WORKS
An electric field is created by applying water on the surface of the membrane and using the water as a conductive medium. The EFVM® equipment delivers a low voltage pulsating electrical charge between the non-conductive waterproofing membrane and the conductive structural deck.
A watertight membrane will isolate the potential difference, while breaches in the membrane will cause an electrical connection to occur. Our certified inspectors read the directional flow of the current with a potentiometer to locate the point of entry with pinpoint accuracy.
The EFVM® technicians then complete the test by conducting a visual inspection of all wall junctions, perimeter details, and membrane penetrations. All breaches are numbered to allow for repairs by the waterproofers onsite and are retested to confirm watertightness. A report follows with picture documentation of every breach and a detailed drawing noting the wire placement and breach locations.
- Small electrical pulses are directed onto the membrane. The electricity searches for a ground connection.
- If the membrane is watertight, the electricity is isolated and does not find a ground connection.
- If the membrane is not watertight, the electricity makes a ground connection and is pulled toward positive poles.
A. Small electrical pulses are directed onto the membrane. The electricity searches for a ground connection.
B. If the membrane is watertight, the electricity is isolated and does not find a ground connection.
C. If the membrane is not watertight, the electricity makes a ground connection and is pulled toward positive poles.
TOP 10 ADVANTAGES OF USING EFVM®:
- Pinpoints the exact location of any membrane breaches
- Defects can be repaired and retested the same day
- Non-destructive to the membrane
- Requires only a limited use of water
- Eliminates removal of overburden to locate a breach
- Can be performed in inclement weather
- Can be performed on sloped structural decks
- Overburden installation can proceed immediately after or during test
- Membrane performance can be monitored through the overburden
- Effective on vertical surfaces
- Developed by ILD® Germany in the early 1990s, EFVM® quickly became a valuable tool for leak investigations on existing systems. Introduced to North America in 2001, the EFVM® testing procedure has become the standard for waterproofing verification.
- ILD® has tested over 200 million square feet of membrane worldwide (including hot or cold liquid applied membranes, coatings, and various sheet membranes). Our certified inspectors perform non-destructive integrity tests on new or existing waterproofing membranes and containment liners using our pinpoint-accurate EFVM® technology.
- Only ILD® technicians are trained and certified in performing EFVM® testing, providing superior detection of all waterproofing defects and breaches (particularly in cases where water exit location may not correspond with point of entry).