Electronic Leak Detection (ELD) Frequently Asked Questions

JST Development provides professional Electronic Leak Detection (ELD) testing for roofing and waterproofing systems using Detec Systems IntegriScan™ technology.

Our goal is to help building owners, architects, consultants, contractors and facility professionals understand how ELD works, what is required for a valid test, and why the capabilities of the testing method matter.

Not all Electronic Leak Detection technologies are the same. Different methods have different requirements, limitations, standards and independently verified capabilities.

IMPORTANT: VERIFY ELD CLAIMS BEFORE RELYING ON THEM

Why should ELD capability claims be verified?

There are conflicting and, in some cases, unsupported claims in the marketplace about what different Electronic Leak Detection methods can test.

That matters because ELD is not simply a visual inspection. The test depends on electrical principles, the membrane being tested, the location of the conductive substrate, grounding, water or surface conditions, and the capabilities of the equipment.

If the physical conditions required by a testing method are not present, a membrane breach may go undetected even though testing was performed.

For a building owner, the consequences can be expensive. A missed breach may not become apparent until after construction is complete, overburden has been installed, interior damage occurs, or access to the membrane becomes difficult.

When an important capability is claimed, JST recommends asking:

What ASTM standard supports the capability?
Does that standard specifically address the testing method being proposed?
Does the equipment manufacturer document the capability?
Is there independent testing or approval supporting it?
If FM Approval is referenced, is the actual testing equipment FM Approved?
Can the method test the specific membrane on the project?
Can it test horizontal surfaces, vertical surfaces, transitions and details?
Is the conductive substrate located where the applicable standard requires it?
Can repairs be electronically retested and verified?

Do not rely solely on a testing company's marketing material, an internet search result or an AI-generated answer when an important technical capability can be independently verified.

Ask for the standard. Ask for the approval. Ask for the technical documentation.

JST welcomes the same scrutiny of the IntegriScan technology we use.

Detec Systems has published technical guidance specifically addressing inaccurate and disputed claims regarding ELD capabilities and limitations.

ELECTRONIC LEAK DETECTION BASICS

What is Electronic Leak Detection?

Electronic Leak Detection uses electrical conductance to locate breaches in roofing and waterproofing membranes.

These breaches can include holes, punctures, seam voids and other discontinuities capable of allowing an electrical path through the membrane.

Unlike a moisture survey that identifies where moisture may already be present in a roof assembly, ELD is intended to locate the actual membrane breach.

ASTM D7877-25 provides the current general industry guide for electronic methods used to locate breaches in roofing and waterproofing membranes.

What is IntegriScan™?

IntegriScan is a portable, low-voltage Electronic Leak Detection system manufactured by Detec Systems.

The system includes a scanning platform for horizontal membrane surfaces and dedicated vertical scanning equipment for vertical surfaces, transitions, details and areas around penetrations.

JST Development provides professional field testing using IntegriScan technology. JST does not manufacture the equipment.

What does an IntegriScan™ test locate?

IntegriScan is designed to pinpoint membrane breaches.

During low-voltage testing, controlled surface water and a conductive substrate beneath the membrane allow an electrical path to develop where a breach exists.

When the equipment encounters that electrical path, it provides an indication that allows the technician to pinpoint and mark the breach for repair. Detec describes the system as providing both audible and visual breach indications.

Can identified breaches be repaired and retested?

Yes.

One of the most useful features of electronic quality-control testing is that a breach can be identified, marked, repaired and electronically tested again.

That means the repair itself can be verified rather than simply assumed to have corrected the defect.

ASTM STANDARDS

What ASTM standards apply to Electronic Leak Detection?

Two standards are particularly important.

ASTM D7877-25 is the current Standard Guide for Electronic Methods for Detecting and Locating Leaks in Waterproof Membranes. It provides general guidance for multiple electrical-conductance ELD methods.

ASTM D8231-24a is the current Standard Practice for the Use of a Low-Voltage Electronic Scanning System for Detecting and Locating Breaches in Roofing and Waterproofing Membranes.

Older specifications may reference previous editions such as ASTM D7877-14 or ASTM D8231-19.

Why is ASTM D8231 important?

ASTM D8231 is much more than a general reference to Electronic Leak Detection.

It establishes a specific standard practice for low-voltage electronic scanning. Its scope expressly includes locating membrane breaches on both horizontal and vertical surfaces. It also requires equipment and testing procedures to meet established detection sensitivity and calibration requirements.

The standard also recognizes use of the scanning method on certain moderately conductive membranes.

These are important distinctions when comparing different ELD technologies.

Does saying that a method is included in ASTM D7877 establish every capability claimed for it?

No.

ASTM D7877 is a broad industry guide covering multiple electronic leak-location methods. It does not mean that every method described within the guide has identical testing capabilities.

Specific claims—such as the ability to test a particular membrane type or vertical surface—should be evaluated against the actual procedure, equipment documentation and applicable standard.

General ASTM recognition should not be confused with independent verification of every claimed capability.

FM APPROVAL

Is IntegriScan™ FM Approved?

Yes.

Detec identifies IntegriScan as the only FM Approved ELD testing method. Versico Roofing Systems separately describes IntegriScan as the first and only FM Approved listing for Manual Scanning Roof Leak Detection equipment.

FM Approval is an important distinction because FM describes its approval process as independent testing and certification backed by scientific research and technical evaluation. FM Approved products and services are listed through the FM Approval Guide and RoofNav.

Why does FM Approval matter?

It provides a form of independent third-party verification.

Anyone can make a statement about the performance of their own testing technology. FM Approval means that the approved product or service has gone through an independent certification process rather than relying solely on the manufacturer's own claims.

For building owners and design professionals comparing ELD services, that is a meaningful distinction.

Are all ELD methods FM Approved?

No.

A testing method can be mentioned in an FM document, used on an FM-insured building, or associated with an FM Approved roofing assembly without the testing equipment itself necessarily carrying FM Approval.

When FM Approval is represented as a qualification, verify the approval that applies to the actual equipment or system being proposed.

MEMBRANE TESTABILITY

What roofing and waterproofing membranes can IntegriScan™ test?

Detec identifies IntegriScan as capable of testing most common roofing and waterproofing membranes, including TPO, PVC, EPDM, modified bitumen, fluid-applied systems and traffic coatings.

A particularly important capability is testing certain semi-conductive membranes, including black EPDM.

The appropriate equipment and procedure depend on the membrane and project conditions.

Can black EPDM be electronically tested?

Yes.

IntegriScan scanning technology can test black EPDM and certain other moderately conductive membranes.

Black EPDM contains carbon black and is electrically different from conventional non-conductive roofing membranes. The testing equipment therefore must be capable of distinguishing the electrical characteristics of the membrane from an electrical path created by an actual breach.

ASTM D8231 expressly states that the electronic scanning practice can be used on certain moderately conductive membranes.

Carlisle also documents that IntegriScan can be used with electrically conductive roofing materials such as black EPDM when the assembly includes an appropriate conductive medium directly beneath the membrane.

Can every ELD method test black EPDM?

No such capability should be assumed.

Detec states that conventional vector mapping and high-voltage testing cannot reliably test semi-conductive black EPDM, while the IntegriScan scanning platform was developed for this application.

Carlisle's technical guidance likewise states that low-voltage vector mapping and high-voltage testing do not work with electrically conductive roof material such as black EPDM, while identifying the scanning platform as capable of testing it when properly configured.

If another testing provider claims equivalent black EPDM capability, ask for the independent technical documentation supporting that specific claim.

Can IntegriScan test vertical surfaces?

Yes.

ASTM D8231 specifically establishes electronic scanning procedures for both horizontal and vertical membrane surfaces.

IntegriScan includes a dedicated Vertical Scanning Unit for vertical surfaces, transitions and detailed areas.

Carlisle also identifies the low-voltage vertical roller as part of the IntegriScan system and notes that it is described within both ASTM D7877 and ASTM D8231.

Can every ELD method test verticals and transitions in the same way?

That should not be assumed.

ASTM D8231 independently establishes a standardized scanning procedure for horizontal and vertical membrane surfaces.

Detec states that its vertical scanning equipment is designed to pinpoint breaches in verticals, transitions, penetrations and detailed areas, while identifying limitations in other ELD approaches for these conditions.

If another provider claims equivalent conclusive vertical-testing capability, ask what independent standard or technical procedure specifically supports that claim.

Can IntegriScan test around drains and penetrations?

Yes, when the assembly and test conditions allow.

The horizontal scanning platform and vertical scanning equipment are designed to work together so that exposed membrane can be evaluated around penetrations, transitions, details and other areas that cannot be addressed by the horizontal platform alone.

THE CONDUCTIVE SUBSTRATE

Why is a conductive substrate required?

Electrical-conductance ELD requires a return path beneath the membrane.

ASTM D7877-25 states that the electrical methods covered by the guide require a conductive substrate under the membrane to serve as the ground-return path for the test current.

Without that electrical path, a breach may not be detectable.

What happens when insulation or coverboard is between the membrane and conductive deck?

Materials such as insulating foam and protection board interrupt the electrical path.

ASTM D7877 specifically addresses this situation and states that it can be remedied by placing conductive material directly under the membrane.

This is one of the most important technical requirements to understand when designing a roof for future ELD testing.

Does it matter where the conductive medium is installed?

Yes.

Placing a conductive material somewhere within the roof assembly is not necessarily equivalent to placing it immediately beneath the membrane.

If electrically insulating coverboard, insulation or another layer separates the membrane breach from the conductor, the required electrical path can be interrupted.

Current ASTM D7877 expressly describes placing conductive material directly under the membrane when insulating materials interrupt the path to the conductive deck.

This is a technical requirement worth verifying when comparing proposed ELD systems.

Can roof fasteners alone provide the conductive substrate?

Metal fasteners may provide individual conductive points, but that does not automatically create a continuous conductive surface beneath the membrane.

Detec cautions that if testing relies on fasteners, water from a membrane breach must actually reach a grounded fastener before an electrical circuit can be established. If it does not, the breach may remain undetected.

For new-construction quality-control testing, JST prefers a deliberately established and verified conductive medium.

TRUGROUND® CONDUCTIVE PRIMER

What is TruGround?

TruGround is a water-based conductive primer manufactured by Detec Systems.

It can be applied to non-conductive substrates such as coverboard, insulation, wood and lightweight concrete to create the conductive layer required directly beneath the roofing or waterproofing membrane.

Is TruGround FM Approved?

Yes.

Detec identifies TruGround as FM Approved. Roofing manufacturer documentation also identifies roof assemblies that have been tested and approved by FM with TruGround incorporated into the assembly.

Is TruGround UL listed?

Yes. Detec identifies TruGround Conductive Primer as UL listed.

Does TruGround replace membrane adhesive or other required primers?

No.

Its purpose is to provide electrical conductivity for ELD testing.

The roofing or waterproofing system still needs to be installed in accordance with the requirements of the membrane manufacturer, including required adhesives, primers and other components.

Who applies TruGround?

TruGround is normally incorporated into the roofing or waterproofing installation by the contractor.

JST can coordinate with the project team and verify electrical continuity and testability before final IntegriScan testing.

HOW INTEGRISCAN TESTING WORKS

Is water required?

Yes, for low-voltage IntegriScan testing.

Water is applied to the membrane surface so that an electrical path can develop where a breach connects the surface to the conductive substrate beneath the membrane. Detec describes IntegriScan as using a low-voltage current and water paths to pinpoint membrane breaches.

No.

The scanning platform creates a localized test area as it moves systematically across the roof surface. Detec identifies minimal setup and no perimeter wire as advantages of the IntegriScan approach.

Does IntegriScan™ require a perimeter wire around the entire test area?

How much setup is required?

When the project is properly prepared, setup is relatively limited.

The technician must establish an appropriate ground connection, confirm testing conditions, wet the membrane and prepare the scanning equipment.

Detec states that the system can typically be test-ready in under ten minutes under suitable conditions.

Does JST verify conductivity before testing?

Yes.

The validity of ELD depends on a functioning electrical path.

JST confirms that the assembly provides the required conductivity and ground path before relying on the final membrane-integrity scan.

What condition should the roof be in before testing?

The membrane should be exposed, accessible and sufficiently clean for the testing equipment to make proper contact with the test surface.

Stored materials, debris and other conditions that prevent access to portions of the membrane should be removed before final quality-control testing.

How much roof can be tested in a day?

Production depends on the project.

A large open horizontal roof can be tested faster than a roof containing numerous penetrations, transitions, separate test areas and vertical surfaces.

Finding breaches also affects production because the purpose of the process is not merely to scan the roof—it is to locate defects so they can be corrected and verified.

JST's priority is thorough, valid testing rather than reaching a predetermined square-foot production number.

COMPARING TESTING TECHNOLOGIES

Are all ELD methods basically the same?

No.

ASTM D7877 describes several electrical-conductance approaches, and the methods can differ substantially in equipment, setup, membrane limitations, test conditions and the areas that can be evaluated.

A building owner should compare capabilities, not simply whether two companies both use the term “ELD.”

How does IntegriScan™ differ from vector mapping?

Both are low-voltage ELD approaches, but they establish the electrical test field differently.

Vector mapping uses a comparatively large wetted test area and perimeter conductor. IntegriScan creates a small localized testing area that moves systematically across the membrane.

Detec identifies several practical differences, including reduced setup, no perimeter conductor around the entire scanning area, less extensive isolation around grounded penetrations, and the ability to test certain semi-conductive membranes such as black EPDM.

Carlisle's technical guidance separately describes the two methods and identifies black EPDM as testable with the IntegriScan platform but not with low-voltage vector mapping.

The purpose of this comparison is not to suggest that vector mapping has no legitimate uses. It is to make clear that the two technologies should not be assumed to have identical capabilities.

How does IntegriScan™ compare with high-voltage ELD?

High-voltage testing uses a substantially higher electrical potential and normally requires a dry membrane.

The appropriate voltage must match the membrane and its thickness. Detec notes that insufficient voltage may miss breaches while excessive voltage can potentially damage the membrane. Detec also identifies semi-conductive membranes such as black EPDM as a limitation of conventional high-voltage testing.

Carlisle similarly notes the dry-surface requirement and the inability of the high-voltage method it describes to test electrically conductive black EPDM.

How does ELD compare with flood testing?

Flood testing and Electronic Leak Detection answer the problem differently.

Flood testing introduces a volume of water to determine whether a waterproofing installation leaks. Electronic testing is intended to locate the individual membrane breach.

Carlisle notes that flood testing can introduce a large amount of water into a new roof assembly when a significant leak is present, while ELD uses much less water—or none, depending on the electrical method.

How does IntegriScan™ compare with infrared thermography?

They answer different questions and can complement one another.

Infrared thermography can identify thermal patterns associated with moisture that may already be present within a roof assembly.

IntegriScan is intended to locate the membrane breach itself.

ASTM D7877 also makes clear that ELD is not intended to replace visual, infrared or other inspection methods and can be used together with other forms of roof investigation.

How does IntegriScan™ compare with impedance or capacitance moisture testing?

Moisture surveys can help identify areas where moisture may already be present within a roof system.

That is not the same as electronically pinpointing the membrane opening responsible for the intrusion.

Depending on the investigation, moisture mapping and IntegriScan testing can be used together to answer two different questions:

Where has moisture traveled?

and

Where is the membrane breached?

EXISTING ROOFS

Can IntegriScan™ be used on an existing roof?

Often, yes.

ASTM D8231 recognizes forensic testing of existing roofing and waterproofing membranes, although specific limitations apply.

Detec also identifies IntegriScan as suitable for investigating existing roofs with active leaks when the necessary electrical conditions are present.

JST evaluates the roof assembly and conductivity before determining whether electronic testing is appropriate.

Does an existing roof always require TruGround?

No.

An existing roof with moisture already within the assembly may have an electrical path from the breach to a conductive deck or other suitable ground.

Detec describes this as one of the circumstances that can allow forensic ELD testing of an existing roof.

The actual testability of the roof must be confirmed in the field.

OVERBURDEN

Can ELD be performed on membranes beneath overburden?

Some electronic leak-location methods can be used in certain covered-membrane applications. ASTM D7877's general scope includes both exposed and covered roofing and waterproofing membranes.

However, covered assemblies can introduce additional variables into the electrical path and can make access to identified breaches much more difficult.

For new construction, JST strongly recommends performing membrane-integrity quality-control testing while the membrane is exposed whenever practical, particularly before pavers, vegetative roof components or other significant overburden conceal the waterproofing.

Should testing through overburden automatically be considered equivalent to testing an exposed membrane?

No.

The complete assembly and testing procedure matter.

Drainage materials, root barriers, insulation, protection layers and other components can affect electrical continuity and access to the membrane.

If testing through substantial overburden is proposed, ask the provider to explain the electrical path, the limitations of the procedure and the independent technical documentation supporting the proposed test.

IMPORTANT CLAIMS TO VERIFY

What types of ELD claims deserve additional verification?

Building owners, architects and consultants should be particularly careful when encountering claims that:

Every low-voltage ELD method can test black EPDM or another semi-conductive membrane.
All ELD methods have equivalent vertical-testing capabilities.
Any location of a conductive medium within the roof assembly is acceptable.
Isolated roof fasteners provide the same test condition as a continuous conductive substrate beneath the membrane.
Testing through complex overburden is equivalent to testing the exposed membrane.
General reference to ASTM D7877 establishes every capability claimed for the testing equipment.
Association with an FM project or FM Approved roof assembly means the testing equipment itself is FM Approved.
Different ELD technologies can be compared solely on the basis that they are all called “Electronic Leak Detection.”

These claims involve specific technical conditions. They should therefore be supported by specific technical documentation.

A company's own statement about the capabilities of its service is not independent industry verification.

Why is this warning important?

Because the greatest concern is not simply receiving an incorrect test result.

The greater risk is receiving confidence from a test that was not capable of detecting a particular condition in the first place.

If a breach remains undetected, the cost may not appear until the membrane has been concealed, the building has been occupied, or water intrusion has damaged other portions of the assembly.

Taking a few minutes to verify the testing method before the work begins can prevent a very expensive misunderstanding later.

QUESTIONS TO ASK ANY ELD PROVIDER

What should I ask before selecting an Electronic Leak Detection service?

JST recommends asking:

What exact ELD method and equipment will you use?
Which ASTM standard applies to that specific procedure?
Can the equipment test my specific membrane?
If the membrane is black EPDM or otherwise semi-conductive, what documentation verifies that capability?
Can the method test horizontal surfaces, verticals, transitions and details?
Where is the conductive substrate located?
How will conductivity and the ground path be verified?
Can identified repairs be electronically retested?
Is the actual ELD testing equipment FM Approved?
If testing through overburden is proposed, what are the method's documented limitations?

A qualified provider should be comfortable answering these questions.

WHY JST DEVELOPMENT USES INTEGRISCAN

IntegriScan:

Uses the low-voltage electronic scanning methodology specifically addressed by ASTM D8231.
Operates within the broader ELD framework addressed by ASTM D7877.
Scans horizontal membrane surfaces.
Includes dedicated equipment for vertical surfaces, transitions and details.
Can test certain semi-conductive membranes, including black EPDM.
Pinpoints membrane breaches so they can be marked for repair.
Allows repaired areas to be electronically retested.
Requires minimal setup compared with large perimeter-conductor test fields.
Carries FM Approval; Detec identifies IntegriScan as the only FM Approved ELD testing method, while Versico identifies it as the first and only FM Approved listing for Manual Scanning Roof Leak Detection equipment.

Most importantly, JST believes building owners should not have to simply take a testing company's word for what its technology can do.

Electronic Leak Detection should be based on verifiable standards, documented testing capabilities, independent approvals and sound electrical principles.

Our objective is straightforward:

Locate membrane breaches, have them repaired, electronically verify the repairs, and provide the building owner with documented membrane-integrity results at the time of testing.

“FINDING WHAT OTHERS MISS”

Why does JST Development use the phrase “Finding what others miss”?

JST Development has been called to numerous projects after the source of a leak could not be located by others.

These projects have included previous investigations by ELD testing providers, engineers, roofing contractors and waterproofing contractors.

JST has been successful in many of these situations because of several factors:

• Selecting the right testing method for the project. No single inspection or testing method is appropriate for every condition.

• Understanding equipment limitations. Knowing what a testing method can and cannot reliably detect is essential to obtaining meaningful results.

• Following established standards and procedures. JST technicians carefully follow applicable industry standards, testing procedures and equipment requirements.

• Experience and training. JST technicians receive appropriate training and certification before performing field testing.

Finding difficult leaks requires more than simply having testing equipment. It requires selecting the appropriate method, understanding its limitations and using it correctly.

That is what JST means by:

Finding what others miss.