- As the operator
walks across the roof pressing the handheld extension probe onto
the surface of the EPDM roofing material, low frequency (17-20 KHz)
signal is passed through the electrically conductive EPDM material.
- A second lead from
the Side-Kick the roof deck by means of an alligator clip connected
to a protrusion through the roof surface or edge trim.
- During an instant
of the AC cycle, an area of the EPDM roofing surrounding the probe is
positive and the deck is negative.
- As opposite charges
are attracted to each other, negative charges will try to flow towards
positive charges and visa versa.
- When the roof construction
is dry, the roof deck and underside of the EPDM is wet, the resistance
decreases by at least 6 order of magnitude (i.e. 1,000,000 times) and
hence a current flows and is measured.
- The greater the
density of moisture (wetness), the stronger the audible and visual signal
from the Side-Kick.
- Leak tracing on
roofs having EPDM or Butyl rubber-waterproofing membranes above the
insulation (water often leaks into the building a considerable distance
from the point of entry into the roof).
- Preventive Maintenance
(indicates presence of moisture between the EPDM membrane and the roof
deck, which cannot be accessed by visual inspection or core cuts alone).
- Assessing condition
and extent of moisture prior to repairs, retrofit or re-roofing.
- Quality control
inspection on new roofs.