What is Electronic Leak Detection?
Electronic Leak Detection is the process of detecting the prescence of and pinpointing the location of faults and leaks in non-conductive waterproof membranes and coatings; such as flat roofing materials and bridge deck coatings.
Buckleys' electronic leak detection equipment falls in to one of two categories: wet or dry testing.
The Wet Roof Pro' uses a conductive perimeter wire on the surface of the test area; covered with water and connected to a 'Pulse Generator' which produces low-voltage current that propagates over the test area via the water.
An earth-return lead connects the Pulse Generator to a known earth point on the building’s structure. Pulses of current are applied across the roof covering via the water on the surface.
This current finds a path to earth through leaks and holes in the non-conductive roofing membrane.
The roof’s entire surface must be adequately covered with water to allow decent current flow.
The roofing membrane or coating thickness has no impact on the wet testing process.
A 'Detector Unit' measures this current flow and directs the operator towards the exact location of any leaks
As the current created by the Pulse Generator propagates away from the boundary wire and towards a fault, the voltage decreases. The Detector Unit's test probes are placed in contact with the roof's surface at a comfortable distance apart. The distance between the two probes enables the Detector Unit to identify a decreasing voltage towards a leak and direct the operator left or right.
By methodically surveying the entire roof's surface, the operator is able to accurately pinpoint any leaks. Once pinpointed and marked, leaks can be isolated with an additional loop of boundary wire connected to the outer boundary wire and testing for further leaks can continue.
The Dry Roof Pro' applies a high-voltage DC current to the surface via an electrode (such as a phosphor-bronze brush) connected to the detector unit. An earth return lead from the detector unit is connected to a known earth on the building’s structure.
As the operator passes the electrode brush over the roof’s non-conductive surface, any holes allow the completion of an electrical circuit - triggering the detector unit’s alarm - highlighting a fault's location.
Dry testing is a far quicker process than wet testing although accurate membrane thickness measurement and detector set-up is fundamental.
Most non-conductive roofing membranes have a small amount of low-level electrical conductivity.
Buckleys' Dry Roof Pro' test kit accommodates this ambient conductivity by allowing the user to set a sensitivity threshold below which the detector’s alarm system will not be triggered.
To successfully undertake a dry roof leak detection test, the roof’s entire surface must be completely dry and free from moisture, although moisture beneath the membrane (from leaks) may actually help the dry testing process, as it can improve conductivity beneath the membrane to earth.
Capable of testing a wide range of coating thicknesses (from 64 microns to 25.6mm) and with an equally wide sensitivity threshold range, there arent many non-conductive coatings or membranes the Dry Roof Pro' can't test.
Simply input the coating's thickness and the Dry Roof Pro' works out the correct voltage to use (acccording to NACE SP0274). Sweep the electrode over the entire test area and every time it passes over a fault, an electrical circuit is created through the fault.
Compatible roof types
There are many types of membranes and coatings. The roofing industry have been successfully using this type of equipment to aid them in finding defects/leaks on flat roofs for a number of years. Each membrane or coating should be checked initially to determine that an effective test can be carried out.
The roof types shown below are known to be compatible with Buckleys' flat roof leak detectors. This is not an exhaustive list and many other non-conductive roofing materials and build-ups may also be testing using our products.
Single-ply on mechanically-fixed foil-faced insulation
Single-ply on tissue-faced insulation
Single-ply on timber
Hot-melt on concrete
Asphalt on concrete