Service
Roof Leak Detection & Condition Surveys
Independent electronic leak detection has become the standard for giving principal contractors, latent defect insurers and clients the assurance that the roof has been handed over without defect.
Talk to Vector
By Ben Hickman, Technical Director
· 30 May 2026 · Updated 11 September 2026
Contributing author, CIRIA C817 (Blue Roofs) · contributing committee member, BS 8102:2022 revision
What a roof leak detection and condition survey is
A roof leak detection survey locates the breach in a waterproofing membrane that is letting water into a building; a roof condition survey records the overall state of the roof build-up, including entrapped moisture, defects and remaining service life. The two are usually instructed together: the condition survey establishes what kind of roof you are dealing with, and the detection work finds the specific point of failure.
Vector Leak Consultants offers the full range of roof leak investigation and integrity testing. We are independent of the installer — our advice is right for the roof, not for a margin or a warranty position. We have experienced field technicians to carry out these services nationwide.
Not only can we identify the cause of a roof leak — we can provide a professional service to project manage the repairs.
If you want to compare the available techniques before instructing anyone, our reference guide to nine flat roof leak detection methods sets out what each one detects and where it fails.
Capabilities
Three core surveys.
Rainfall simulation
Controlled water testing that reproduces the leak conditions in situ. Used to confirm a hypothesis or to verify a repair.
Learn more →Tramex entrapped-water survey
Capacitance moisture mapping across the roof build-up. Locates trapped water and zones of failed waterproofing — without breaking the surface.
Learn more →Electronic leak detection
HVELD and LVELD methods applied per LRWA GN18:2025. Precise breach location on accessible single-ply, bituminous and liquid-applied membranes.
Learn more →Frequently asked questions
What is a roof condition survey?
A roof condition survey is a structured assessment of a roof’s waterproofing and build-up that records its present condition, identifies defects and entrapped moisture, and sets out what needs to be done. It differs from a leak investigation in purpose: a condition survey describes the state of the whole roof, while a leak investigation locates one specific breach.
What is the difference between leak detection and a condition survey?
Leak detection answers “where is the water getting in?” and produces a located breach. A condition survey answers “what state is this roof in?” and produces an inventory of defects, moisture distribution and remaining service life. Most instructions need both — the survey establishes the context, the detection work finds the breach.
Which survey methods do you use?
Rainfall simulation to reproduce leak conditions, Tramex entrapped-water surveys to map moisture without breaking the surface, and electronic leak detection — both high-voltage and low-voltage methods applied per LRWA GN18:2025.
Which standards do your surveys follow?
Electronic integrity testing follows LRWA GN18:2025. Flat roof inspection and maintenance follows BS 6229:2025. Where the roof sits over a buried or below-ground structure, BS 8102:2022 governs the waterproofing design the survey is assessing against.
Can you survey a roof that is already covered with ballast, paving or planting?
Yes. Electronic integrity testing needs access to the membrane, so where the waterproofing is concealed we use buried leak location instead — electrical field mapping that locates the breach through the overburden, without strip-out.
Are you independent of the installer?
Yes — completely. We hold no installation contracts and no manufacturer ties, so the advice is right for the roof rather than for a margin or a warranty position.
Do you provide a report suitable for insurers?
Yes. Every survey produces a written report with a photographic and survey record, suitable for contractors, owners and insurers. Where a repair follows, a post-repair verification survey confirms the fix worked.
Do you work outside London, and can you manage the repair?
Yes to both. Vector has experienced field technicians carrying out leak detection and condition surveys nationwide, and as well as identifying the cause we project-manage the repairs and verify the fix afterwards.
Related technical resources
BS 6229:2025 · LRWA GN18:2025 · 9 leak detection methods compared · Monitoring vs integrity testing · How we approach an investigation
Get an estimate and an initial assessment.
Tell us about the leak. We will be on site, with the right equipment, at the right time.
Talk to Vector