Trace and Access Leak Detection for London Properties
When a pipe fails inside a wall or beneath a screed floor, the water has often been spreading for weeks before the damage becomes visible. Finding the source requires specialist equipment, not guesswork. Without a confirmed location, your insurer will not approve repair costs, and you cannot claim for the reinstatement of any floor or wall that needs to be opened up.
Signs You May Need a Trace and Access Survey
When a pipe fails inside a wall or beneath a screed floor, the water has often been spreading for weeks before the damage becomes visible. Finding the source requires specialist equipment, not guesswork. Without a confirmed location, your insurer will not approve repair costs, and you cannot claim for the reinstatement of any floor or wall that needs to be opened up.
ClearFlow carries out trace and access surveys using thermal imaging cameras and tracer gas detection equipment. We locate the leak source precisely, then issue a written report documenting the cause, the method used and the exact coordinates of the breach. The report is formatted to meet insurer requirements and is accepted without challenge by all major UK home insurers and loss adjusters.
Trace and access cover is included in most standard home insurance policies, but many policyholders do not know it exists until they need it. If your policy includes it, the cost of the survey and the remedial access work is typically recoverable from your insurer. We can advise on what your policy is likely to cover and what documentation your insurer will require before we begin.
- Unexplained rise in water bill with no visible leak
- Damp patches or staining on walls, floors or ceilings
- Sound of running water when all taps are turned off
- Soft or lifted tiles above an underfloor heating circuit
- Mould appearing on walls without an obvious source of moisture
- Water meter spinning continuously when no water is in use
- Unexplained cold or warm patches on floor surfaces
How We Carry Out a Trace and Access Investigation
We review the symptoms, building type and pipe layout before selecting any equipment.
One or more methods are deployed to identify the source zone, typically narrowed to within 10–30 cm.
A second method cross-checks the result before we mark the repair point — no guesswork.
A written report with findings and photographs is issued — suitable for insurance claims.
Trace and Access Situations We Cover
Underfloor heating pipe failure
Pinhole corrosion or joint failure in a pressurised underfloor heating circuit is one of the most common trace and access referrals we receive. Thermal imaging reads the temperature differential directly from the floor surface, and tracer gas confirms the precise breach point. No screed is broken until the exact location is identified.
Supply pipe leak in screed floor
A cold or hot water supply pipe running beneath a concrete or sand-and-cement screed can fail at any point, often without a visible drip at the surface. We detect the leak path using tracer gas and mark the breach for targeted access, minimising the area of floor that needs lifting.
Concealed leak inside a wall
When a pressurised pipe runs inside a studwork or masonry wall, a failure can saturate insulation and plasterboard without reaching the surface for weeks. Thermal imaging identifies the moisture zone and tracer gas pinpoints the pipe breach, keeping the access opening as small as possible.
Home insurance trace and access claim
If your home insurance policy includes trace and access cover, we carry out the full investigation and issue a report formatted to your insurer's requirements. We can liaise directly with your loss adjuster if required and have supported successful claims across all major UK insurers.
Leak between floors or properties
Where a supply pipe serves both an upper and a lower property, confirming which section is at fault is essential before any access work begins. Our investigation documents the source and confirms responsibility, which resolves disputes between leaseholders and their respective insurers.
Damage visible but source unknown
Sometimes the damage is extensive but the source cannot be identified by inspection alone. We carry out a systematic pressure-test and detection sweep of all suspect pipe circuits in turn, and consistently locate leaks that visual inspection and other engineers have failed to find.
What You Can Expect
We've been detecting hidden leaks across London for years. Every engineer is directly employed by us, DBS-checked and WaterSafe registered. We don't subcontract.
- Written insurer-accepted report included with every investigation
- No Find No Fee: if we cannot locate the source, you pay nothing
- Thermal imaging and tracer gas used together for cross-confirmed results
- Non-invasive: no floors or walls opened until the exact breach point is confirmed
- London-wide coverage, with engineers on-site within 2 to 4 hours for urgent cases
- Directly employed, DBS-checked engineers, no subcontractors
Trusted Across London
Absolutely quality service and what plumbers should exemplify. Turned up when they said, was kind, answered all my questions and wasn't being dodgy with anything. Skilful and efficient! Would highly recommend.
The technician arrived on time, was polite, and explained the process clearly before starting. They used advanced, non-invasive equipment to locate the leak quickly without causing any unnecessary damage to my property.
Really impressed with the service. They responded quickly and were able to accurately detect the leak without causing unnecessary damage. Professional, efficient, and clearly experienced — would highly recommend to anyone dealing with a hidden leak.
Wayne and his colleague came and within an hour found the leak deep underneath my cellar and came up with a perfect plan which made the pipe redundant and re-routed it the following morning. An excellent option if you're having a problem with a leak you cannot find.
Called Wayne Monday and he was round Tuesday evening — came out of hours to help me out. Very professional, punctual and great with communication. Fair priced too. Will definitely recommend and use again.
Contacted them and they were at the property within an hour. Honest, well priced and gave a detailed report that will likely save me hundreds of pounds. Will definitely recommend and if necessary will use again.
Wonderful efficient service — came out the same day, nothing was too much trouble. Engineers were professional and polite, explained the problem and persevered until the blockage was cleared. Would highly recommend this company.
The staff were so professional and friendly. The technician was nice and informative — he advised me the leak was outside and wrote me a report which I sent to Thames Water. In a few days they sent a repair team and found the leak. Clear Flow are great at what they do.
I received a letter from Thames Water about high water usage. Wayne arrived on time, was so professional, guided me through what he was doing and advised me of the next steps. He also wrote me a report to send to the water board. 100% recommend.
How We Confirm the Leak
A trace and access investigation begins with a pressure test of the suspect pipe circuit to confirm an active leak is present. Once confirmed, our engineer introduces a hydrogen-nitrogen tracer gas mix into the pipe under low pressure. The gas migrates through the pipe wall at the point of failure and permeates upward through the surrounding substrate. A handheld electronic probe detects the gas at the surface, accurate to within a few centimetres even through concrete screed, sand-and-cement bed or tile adhesive.
Non-Invasive Detection Methods
Thermal imaging is used alongside tracer gas wherever the pipe layout permits. An active leak in a pressurised hot water or heating circuit creates a measurable temperature differential at the floor or wall surface, which the thermal camera reads as a heat signature. The two methods cross-confirm each other: thermal imaging narrows the search zone and tracer gas pins the exact breach point. This combined approach reduces false positives and means any access opening is kept to the absolute minimum necessary.
Detailed Investigation Report
At the end of every investigation, we issue a written report containing the findings, the detection method used, annotated photographs of the breach location and a clear repair recommendation. The report is structured to meet the evidential requirements of UK home insurers and loss adjusters, so your claim handler has everything needed to process the claim without requesting further documentation. Reports are issued the same day in most cases and can be sent directly to your insurer or loss adjuster on request.
Understanding Your Trace and Access Policy
It is worth understanding what trace and access cover does and does not include. The policy typically pays for the cost of the investigation itself and the making good of any floors, walls or surfaces that needed to be opened to access the pipe. It does not cover the cost of repairing the pipe, which is classified as maintenance rather than accidental damage. Some policies also impose a limit on the total trace and access payout, so it is worth checking your policy schedule before the investigation begins.
Trace & Access Investigations
FAQs About Trace & Access
Can't find what you're looking for? Call us on 0203 886 2316 and we'll answer on the spot.
What is trace and access cover and does my home insurance include it?
Trace and access cover is a benefit included in many standard home insurance policies. It pays for the cost of locating a hidden leak and exposing it for repair, but does not cover the cost of fixing the pipe itself, which insurers treat as a maintenance matter. Check your policy schedule under additional benefits, or call your insurer directly to confirm whether this cover is included.
What does a trace and access survey involve and how long does it take?
Our engineer uses thermal imaging and tracer gas detection to locate the source of a hidden leak without opening any floors or walls. The survey typically takes one to three hours depending on the size of the property and the complexity of the pipework. At the end, you receive a written report with annotated photographs and a precise description of the breach location.
How much does trace and access leak detection cost in London?
Most residential trace and access investigations in London fall between £300 and £600, depending on property size and the number of pipe circuits to be tested. If your home insurance policy includes trace and access cover, these costs are typically recoverable from your insurer. We operate on a No Find No Fee basis, so if we cannot locate the source you pay nothing for the investigation.
Where can I find a trace and access plumber near me?
ClearFlow covers London and the South East, with engineers across all major zones of the city. We can typically attend within 2 to 4 hours for urgent cases. Call us directly for an accurate arrival estimate based on your postcode and the nature of the leak.
What happens if my trace and access claim is refused by my insurer?
The most common reasons for a refused trace and access claim are that the policy does not include the cover, a specialist report was not obtained before access work was started, or the reported cause does not match the policy wording. Our written report is structured to satisfy insurer requirements from the outset. If you have already been refused, we can review your situation and advise whether a re-submission supported by our documentation is likely to succeed.