Do I need a conductive substrate for electronic integrity testing?

Yes. Both low-voltage wet testing and high-voltage dry testing require a conductive substrate directly below the waterproofing membrane — typically a concrete or metal deck. On timber decks, a conductive medium such as wire mesh or conductive glass felt can be installed during construction to enable EIT. See LRWA Guidance Note 18 (2025) for full substrate requirements.

Can you electronically test a green roof or buried waterproofing?

Not with standard EIT once the overburden is in place. For buried waterproofing, the correct method is electrical field mapping (EFM) — a buried leak location technique that locates membrane breaches to within approximately one metre without lifting the overburden. CIRIA C817 and the GRO Green Roof Code both recognise EIT as a pre-covering QA method and EFM as the post-burial investigation method.

What is the difference between moisture mapping and leak detection?

Moisture mapping tells you where moisture has accumulated within the roof build-up. It does not tell you where the membrane has failed. Leak detection methods such as low-voltage EIT or electrical field mapping locate the actual breach in the membrane. The two are complementary: moisture mapping identifies which areas need investigation; breach-location methods find the source.

Is flood testing safe for flat roofs?

Flood testing carries real risks. A 150mm head of water adds approximately 150kg per square metre of loading — structural sign-off is essential. Water can take many hours to manifest internally, making short test periods unreliable. Flood testing can also cause structural deflection that opens up laps and details. It has a legitimate role in post-repair verification of specific, structurally appropriate areas only.

What qualifications should a roof leak detection specialist hold?

Look for: NVQ Level 3 in waterproofing testing and inspection; RAWTA membership (the Roofing and Waterproofing Test Association); and a demonstrable CV in flat roofing and waterproofing systems. Under the Building Safety Act 2022, appointing an incompetent inspector carries legal liability for duty holders.

Which leak detection method works on a single ply membrane?

For QA of weld continuity at laps and details, vacuum box testing is most reliable. For field-sheet investigation with a conductive substrate, low-voltage wet EIT is standard. High-voltage dry testing also works on non-conductive single ply on conductive substrates. Black EPDM membranes are generally not suitable for EIT due to carbon black content.

How does permanent sensor monitoring differ from leak detection surveys?

Leak detection surveys are point-in-time investigations locating a breach. Permanent sensor monitoring is continuous infrastructure embedded during construction, monitoring moisture in real time and triggering automated alerts. CIRIA C817 specifies permanent monitoring for blue-green roofs; BS 6229:2025 references electronic devices for detecting leaks between inspections.

Does electronic leak detection work in the rain?

Low-voltage wet testing requires a wet surface so rain is not a problem. High-voltage dry testing requires a dry membrane and cannot be performed in wet conditions. Tramex capacitance mapping works in most weather. Infrared thermography requires dry sunny conditions. Tracer gas is best in calm dry conditions as wind disperses escaping gas.

Roof Leak Monitoring & Location

Stop hoping the roof is watertight.
Start knowing it is.

Preventing, monitoring, and locating leaks.

INDEPENDENT ROOF LEAK SPECIALISTS • 20+ YEARS EXPERIENCE • EXCLUSIVE EUROPEAN SENSOR TECHNOLOGY • TRUSTED BY TIER 1 CONTRACTORS

The problem most roofs have — and nobody talks about

Landscape roofs, green roofs and buried waterproofing systems are complex. When they leak, the water travels. The entry point and the symptom are rarely in the same place. Visual inspection finds nothing. The contractor visits twice more. The defect liability period ticks down. Meanwhile the damage spreads — slowly, invisibly, expensively.

Vector changes that equation. We start with an initial site inspection to assess the roof, understand the construction and pinpoint the investigation strategy. From there, our buried leak location survey maps the defects — producing a contour map that locates leaks to within approximately one metre. No guesswork. No repeat visits hoping to catch it in the act. Just precision, backed by European sensor technology that nobody else in the UK can offer.

What our clients say

“Their approach accurately identified numerous leak locations, allowing us to resolve the issues with precision and minimal disruption—much to the relief of both the client and residents. I would highly recommend Vector for similar challenges.”

Martin Farrell | Senior Contract Manager, Balfour Beatty

Waterproofing Design Review

Independent review of your waterproofing specification at RIBA Stage 3. Before systems are locked in. Before mistakes become expensive. We tell you what the contractor won’t.

Sensor Monitoring & PPM

Embedded sensors. Continuous data. You stop hoping and start knowing. Ideal for complex landscape roofs, green roofs and CLT structures where moisture ingress is a latent risk that doesn’t show itself until it’s expensive.

Buried Leak Location

Electrical field mapping. We locate the exact breach in your waterproofing membrane without destructive investigation. One visit. One report. One precise location. No guesswork.

How We Work

From design review to lifetime monitoring — we protect the roof at every stage.

01 Design Review

We review the waterproofing design at RIBA Stage 3 — catching risks before they become defects.

02 Sensor Design

We design a bespoke leak sensor array tailored to the building’s construction and risk profile.

03 Quality Assurance

On-site QA during installation ensures the waterproofing and sensors are commissioned correctly.

04 Long-Term Prevention

Planned preventative maintenance and continuous sensor monitoring — protecting the building for its lifetime.

Trusted by leading contractors and developers

BALFOUR BEATTY | ARGENT | BARRETT | JOSEPH HOLMES | QUINTAIN

The technology — and the people behind it

Vector has built exceptional partnerships with several niche technology suppliers across Europe. Our leak sensors come from Norway. Our buried leak testing technology comes from the Netherlands. These are precision instruments built for exactly this purpose — and we’re the only firm in the UK with access to them.

But technology is only as good as the people using it. Vector’s team combines a lifetime of flat roof experience — from hands-on defect investigation and quality assurance on some of the UK’s most complex roof systems — with structural waterproofing consultancy at expert witness level. It’s why we find what others miss, and why Tier 1 contractors and serious developers trust Vector with their most difficult projects.

Roof Leak Monitoring & Location

Stop hoping the roof is watertight.Start knowing it is.