Electronic leak detection for commercial roofs
Electronic leak detection (ELD) finds the exact point where a waterproofing membrane is breached, without cutting or flooding anything. A small electrical potential across the membrane can only cross where the membrane is compromised, and the equipment traces that current to the spot, which gets marked on the roof, mapped on a plan, and written into the report.
When a roof needs this test
At close-out
A new roof or waterproofing system, tested before the warranty starts and before the overburden goes down. The breach a crew made in week three gets found now, while the fix is an hour's patch rather than a tear-up.
When it already leaks
Water shows up inside a building far from where it enters. ELD works from the membrane side and finds the entry point itself, so the repair happens where the breach is, not where the stain is.
Before and after repairs
Before a repair program, a test scopes the real work: how much of the roof is actually compromised. After repairs, a re-test proves they hold.
Low voltage or high voltage: the roof decides
Low voltage
A thin film of water on the membrane carries the signal; probes read the voltage field and vector straight to the breach. Suits membranes over a conductive deck, and works on finished roofs, in many cases under pavers or vegetation.
High voltage
A conductive brush sweeps the dry membrane and arcs at a breach. No water at all, so it suits roofs that cannot be wetted, works on vertical surfaces, and finds pinholes a water-based method can miss. The signal is low-current, at static-electricity scale rather than hazard scale.
Both methods test single-ply membranes, hot melt, liquid-applied systems, built-up felt, asphalt, torch down, silicone, and white EPDM. Comparing electronic testing against the old way? Read ELD versus flood testing. For a flat roof that is actively leaking, start at flat roof leak detection. Specifying a new assembly over a non-conductive deck? The conductive mesh specification, Section 07 01 91, is published for project use.
What the test runs to, and who runs it
Leaks located by Atlantic Testing Services technicians.
The standard guide for electronic methods of locating breaches in waterproofing membranes. Our tests run to it.
The standard practice for low-voltage electronic scanning specifically.
High voltage and low voltage both, carried in-house, so the roof picks the method. Firms that own one platform test with the one they own.
Most ELD specifications require the testing agency to show at least five years of ELD experience, a bar written into specs for good reason: the method is only as accurate as the field setup. Our own test and material specifications, including scope language you can paste into a project spec, are published on the specifications page and summarized for specifiers on Specify Atlantic.
Consultants, not contractors
Atlantic Testing Services tests, marks, maps, and reports, and bids none of the repair work it finds. On a close-out or warranty test, that independence is the product: the owner, the insurer, and the contractor proving the work was sound can all read one report without asking who profits from its conclusions.
Every test delivers a marked roof plan locating each breach, photographs of each finding, and a re-test of the repairs.
What drives the price of a test
Four things set the cost of an ELD test: the roof area, the method the roof needs (wet low-voltage or dry high-voltage), whether overburden has to be moved to reach the membrane, and mobilization, meaning where the building is. A test with a full marked plan and report typically runs a small fraction of the cost of one exploratory tear-off, and unlike the tear-off it finds every breach the survey covers, not just the one you opened.
Call with the roof size, membrane type, and location and we will give you a real number, usually the same day.
Questions owners and specifiers ask
What is electronic leak detection?
Electronic leak detection (ELD) is a non-destructive test that puts a small electrical potential across a waterproofing membrane and follows the current to any point where it passes through. Because current only crosses the membrane at a breach, the method locates the exact point of failure, not just the general area, without cutting, flooding, or damaging the roof.
How accurate is ELD?
ELD locates the breach itself, to the point, rather than narrowing down an area the way moisture surveys or visual inspection do. It finds breaches too small to see, including pinholes, before water shows up inside the building. Accuracy depends on correct setup, meaning a conductive path under the membrane and a properly isolated test field, which is why specifications require an experienced agency.
How much does electronic leak detection cost?
Cost depends on roof area, the method the roof needs (wet low-voltage or dry high-voltage), whether overburden such as pavers or vegetation must be moved, and where the building is. A single mobilization with a marked roof plan and written report typically costs a small fraction of one exploratory tear-off, and unlike a tear-off, it tells you every breach in the tested area, not just the one you opened. Call with the roof size and membrane type and we will give you a number.
Do I need low voltage or high voltage testing?
The roof decides, not preference. Low voltage (also called EFVM or LVIT) wets the surface with a thin film of water and suits membranes over a conductive deck, including many roofs with overburden. High voltage sweeps a dry membrane with a probe and suits roofs that cannot be wetted, vertical surfaces, and pinhole-level breaches. Tell us the membrane, deck, and overburden and we will tell you which one your roof needs.
Is high voltage testing safe for the building?
Yes. The test signal is low-current, comparable in energy to everyday static electricity. It poses no hazard to people, the structure, or building systems, and it introduces no water. The equipment is purpose-built for membrane integrity testing and operated by certified technicians.
When should ELD be specified?
The highest-value moments are close-out of a new roof or waterproofing system (before the warranty clock starts), leak investigations where interior signs do not point to a source, before an overlay or repair program to scope the real work, and after repairs to verify them. Many specifications now require an ELD test at close-out; scope language you can paste into a spec is on our specification page.
Tell us about the roof
Membrane, deck, roughly how big, where it is, and what stage the job is at. If electronic testing is not the right tool for it, we will tell you that instead.