CMW Electronic Leak Detection (ELD) Services

CMW Roof Consulting Inc provides electronic leak detection services to a range of clients for roofing and waterproofing projects. We offer ELD testing for High Voltage (dry testing) and Low Voltage (wet testing), designed to identify defeciency in the assembly of building enclosures.

Currently, CMW has been trained and has the capability to perform High-Voltage testing, Low-voltage horizontal scanning platform, and Low-Voltage vertical membrane scanning.


Electronic Leak Detection Intro

The goal of a roofing or waterproofing system is that it is watertight.  For years, water (flood) testing was the go-to ‘leak’ detection method.  ELD testing was introduced to North America about 20 years ago.  While flood testing detects leaks, ELD testing detects breaches in the membrane.

So, what is the difference?  By definition, a leak is the appearance of water below the deck and a breach is defined as defect or abnormality in the membrane that allows water to “breach” the membrane onto the deck (substrate).

Testing Benefits

Pinpoint Exact Breaches

As we said, for years flood testing was the go-to method, but ELD testing can provide additional benefits including, being able to pinpoint exact breaches, being able to identify breaches when the underside of the area in question is not accessible, and ease and efficiency of repairing found breaches or defects.

Also, once a breach is identified and repaired, the repair can be tested immediately, whereas flood testing would require the area to be dried, then repaired, and then flood tested again (24-72 hours) to reassess.  The two primary methods of testing are low-voltage (wet) testing and high-voltage (dry testing).

*Note typical flood testing requires water to be 4-inches deep, whereas low-voltage requires that water create a continuous path extending from the breach to the grounded substrate and high-voltage requires that the surface be dry, and an air gap extends from the breach to the grounded substrate.

Testing Methods

ELD Mapping, Scanning, & Testing

ASTM D7877 recognizes 4 types of ELD test methods and discusses their applications, which are Low-Voltage horizontal scanning platform, Low-Voltage field vector mapping, Low-voltage vertical membrane scanning, and High-voltage membrane testing.

Although these methods differ, they all require the same basic principles.  They all require a conductive substrate directly below the membrane, a ground connection connected to the substrate, exposed membrane (no overburden), and an electrical pathway from the top of the membrane to the conductive substrate.

ASTM D7877 also discusses the limitations of the four methods.  There are 3 basic types of roofing and waterproofing assemblies, non-conductive, semi-conductive and conductive membranes.  All ELD methods are capable of testing non-conductive membrane, low voltage scanning platform is the only method for semi-conductive membranes, and typically a conductive membrane cannot be ELD tested.

Building Enclosure Consulting

Building Enclosure Consulting, also known as Building Envelope, is focused on helping prevent problematic issues before they escalate by bringing decades of experience in the Construction Industry to the table.

Leak & Moisture Investigations

Investigating issues related to water leakage, condensation, or moisture is a cornerstone of CMW.

These investigations include identifying sources of water intrusion, cause of condensation, and cladding deterioration or failure.

Construction Phase Services

CMW provides construction phase services to a variety of clients. These services are intended to further the design review by providing observation services during installation of the work. CMW helps to ensure conformity of the installation regarding the contractors work.

Recent Projects

Construction observation

Burlingame 3 Affordable Housing

For City of Aspen, CO

Building Condition Assessment

Multiple Retail Shopping Centers


Roofing & Waterproofing

Roof Replacement Projects

Multiple School Districts, CO