Gaston Leak Detection investigates hidden water leaks, heating pressure loss and underfloor heating leaks across Hertfordshire, Buckinghamshire and north Greater London. Based in Watford, we combine specialist equipment with a methodical investigation to trace leaks beneath floors, behind walls and within pipework.
Tracing hidden leaks beneath the surface.Specialist tracer gas detection in action.
Hertfordshire, Buckinghamshire & North LondonWater & heating leaksTrace & access investigationsClear findings & next steps
01 / Explore the equipment
Our leak detection methods. How we investigate.
Hover over a method to explore it. On a phone, tap to select. We choose the tools to suit your property — every investigation is different.
Surface temperature patterns
Thermal imaging
A thermal camera turns surface temperature differences into a colour image, helping us identify patterns worth investigating.
Equipment we use
Infrared thermal imaging camera
How we work through it
Survey accessible walls, floors and pipe routes under suitable operating conditions.
Look for unusual warm or cool areas and compare them with the surrounding surfaces and known pipework.
Cross-check relevant patterns with moisture readings and plumbing tests before drawing conclusions.
Particularly useful for
Hot-water and heating pipe routes, underfloor heating investigations and moisture-related temperature patterns.
What the result tells us
It cannot see through walls or directly detect water. A thermal pattern is a clue, not proof of a leak.
Tracing concealed pipe leaks
Tracer gas detection
A specialist tracer gas is introduced into suitably prepared, isolated pipework. A detector searches for gas escaping from a defect and reaching the surface.
Equipment we use
Tracer gas, regulator and sensitive gas detector
How we work through it
Assess suitability, isolate the relevant section and prepare or drain it as required. Introduce the test gas at an appropriate controlled pressure.
Scan possible pipe routes, joints and surrounding surfaces with a sensitive probe. The commonly used mixture is 95% nitrogen and 5% hydrogen.
Compare and repeat readings around the suspected area, considering where gas may have travelled through voids or floor layers.
Particularly useful for
Concealed water and heating pipes, including leaks where thermal or acoustic evidence is limited.
What the result tells us
Gas may emerge away from the defect. Results need interpretation and may require targeted access for confirmation.
Listening for escaping water
Acoustic listening
Water escaping from a pressurised pipe can create vibration and sound. Sensitive listening equipment helps us compare those signals along a suspected pipe route.
Equipment we use
Electronic listening equipment and contact or ground sensors
How we work through it
Assess pipe material, water pressure and background noise to decide whether acoustic testing is suitable.
Listen at accessible pipework and appropriate surfaces, comparing the sound at different positions.
Recheck stronger signals and compare them with the pipe layout and other test results.
Particularly useful for
Pressurised supply leaks that produce a detectable sound, particularly where pipework transmits vibration well.
What the result tells us
Small leaks, plastic pipes, depth and traffic or equipment noise can reduce the strength or clarity of the signal.
Following the spread of damp
Moisture mapping
A series of moisture readings helps us map the affected area and understand how far dampness has travelled through the building fabric.
Equipment we use
Moisture meter with suitable surface or probe measurements
How we work through it
Inspect visible damage and take reference readings in comparable, apparently dry areas.
Measure accessible surfaces systematically, recording higher readings and changes across walls, floors or ceilings.
Compare the pattern with the building layout, nearby fittings and other test findings.
Particularly useful for
Damp patches, water-damaged ceilings and walls, and identifying areas for closer investigation.
What the result tells us
Water can travel away from its source. Material type, salts and concealed metal can affect readings; the wettest point is not always the leak location.
Checking whether a system holds
Pressure testing
Monitoring pressure in an isolated section helps establish whether water may be escaping from that part of the plumbing or heating system.
Equipment we use
Test gauge, suitable connections and isolation valves
How we work through it
Identify the system and isolate the section being assessed, checking accessible valves and connections.
Apply or establish a suitable test pressure and allow conditions to settle before monitoring over an appropriate period.
Assess any pressure change, checking for passing valves, temperature effects and other causes before recommending further tracing.
Particularly useful for
Narrowing down heating pressure loss or distinguishing between suspect hot and cold supply sections.
What the result tells us
A pressure drop does not identify the leak position by itself. Test conditions and isolation must be considered.
Checking unexplained water use
Water flow & meter tests
Checking water movement when outlets are shut helps us investigate unexplained consumption and establish which part of the supply needs attention.
Equipment we use
Water meter or flow measurement and supply isolation
How we work through it
Check that taps and relevant water-using appliances are off and account for cistern filling or other expected use.
Observe the meter or measure flow over a timed interval, then compare results with suitable sections isolated.
Use the isolation results and measured loss to plan a more focused investigation.
Particularly useful for
High water bills, continuous meter movement and suspected incoming mains or internal supply leaks.
What the result tells us
Passing valves, shared supplies and hidden appliance use can complicate results. A flow test alone cannot pinpoint the defect.
A closer look inside concealed spaces
Endoscope inspection
A small camera can help us inspect areas that are difficult to see directly, such as under baths, within boxing or behind accessible panels.
Equipment we use
Flexible inspection camera with illuminated camera head
How we work through it
Identify a safe existing opening or accessible panel from which to inspect the suspected area.
Guide the camera into the available space and inspect visible pipe joints, waste connections or signs of water.
Where suitable, observe during a controlled test and record the visible findings. Any new access opening is agreed first.
Particularly useful for
Restricted voids, concealed fittings and visually checking suspected drips or water tracks.
What the result tells us
The camera only sees within its line of sight. Insulation, obstructions and inaccessible cavities can prevent a complete view.
Separating waste and seal leaks
Dye & controlled water tests
Testing one fitting or water pathway at a time helps distinguish a leaking waste connection from a seal, overflow or another source.
Equipment we use
Suitable tracing dye and controlled fixture testing
How we work through it
Inspect the fitting and plan separate checks of the waste, overflow or surrounding seals as appropriate.
Run controlled amounts of water and use suitable tracing dye where it can help identify the route, protecting finishes and monitoring for leakage.
Observe accessible areas below or nearby, stopping when sufficient evidence is obtained and comparing results between tests.
Particularly useful for
Bath and shower wastes, overflows and leaks that appear only when a particular fitting is used.
What the result tells us
Intermittent leaks may not occur during the visit. A test with no observed leakage does not rule out every possible defect.
These methods form our investigation toolkit. Suitability depends on the system, access and conditions; not every visit requires every test.
02 / From first signs to next steps
A clear process. No unnecessary guesswork.
We build a picture from the symptoms, isolate possible causes and compare test results before recommending the next step.
01
Initial non-invasive assessment
We discuss when the leak appears, inspect accessible fittings and damage, and assess the plumbing layout. Moisture readings, thermal checks and suitable supply or pressure tests help establish which system may be affected.
Outcome: initial findings and a proposed investigation plan.
02
Detailed tracing & investigation
Where further work is needed, we explain the scope and cost before proceeding. Targeted testing may include tracer gas, acoustic listening, isolating sections and inspecting concealed areas. Any invasive investigation is discussed and agreed first.
Outcome: a suspected location supported by evidence.
03
Agreed access & confirmation
Where required, we agree targeted access to visually confirm the defect and assess repair options. Repairs, follow-up testing and making good are clarified separately so you understand what is included.
Outcome: confirmation, findings and practical next steps.
You stay informed throughout. If the evidence points to a roof, seal, waste connection or another source rather than a pressurised pipe, we explain the findings and the appropriate next step.
03 / Choosing the right approach
Your symptoms guide our investigation.
These are typical starting points, not a diagnosis. We select and adapt tests after assessing your property.
Boiler losing pressureSystem checks and isolation → pressure testing → thermal, acoustic or tracer gas investigation where suitable.
Underfloor heating pressure lossManifold and isolation checks → assess individual circuits where practical → pressure testing and targeted tracing where suitable.
Unexpectedly high water billsMeter and flow checks → supply isolation → targeted tracing of the affected pipework.
Damp walls or wet floorsMoisture mapping → thermal survey → checks to distinguish supply, waste and building-related sources.
Leak when the shower runsControlled fixture testing → separate checks of supply, waste and seals → dye or camera inspection if appropriate.
Leak during heavy rainfallPattern and moisture assessment → accessible visual or camera inspection → advice on roofing or building repairs where indicated.
04 / Good to know
A little clarity before we arrive.
Will you need to lift floors or open walls?
We start with non-invasive methods wherever practical. Concealed defects may still require targeted access for visual confirmation or repair. We explain the evidence, proposed access and costs before agreed invasive work begins.
Can one device pinpoint every leak?
No. Pipe material, depth, floor construction, background noise and the size of the leak all affect results. Combining methods helps us test a suspected location rather than relying on a single reading.
Can a thermal camera see through my walls?
No. It records surface temperatures. Patterns may indicate a concealed hot pipe or an area affected by moisture, but insulation, heating and other conditions can create similar patterns. We interpret images alongside other evidence.
What is trace and access?
Trace and access describes investigating the source of a concealed leak and making access where needed. The investigation, repair of the pipe and reinstatement are different elements. If you intend to claim, check your policy and your insurer’s authorisation requirements. We can provide investigation findings; cover and claim acceptance are determined by your insurer.
Which areas do you cover?
We are based in Watford and prioritise Hertfordshire, Buckinghamshire and north Greater London. Contact us with your postcode to confirm availability for your property.
Will I receive an investigation report?
We provide detailed findings and practical recommendations following the agreed investigation. Reports can support an insurance claim where applicable; cover and claim acceptance remain subject to your policy and insurer.
What should I tell you when I book?
Tell us when the problem started, whether it is constant or intermittent, any boiler pressure loss or high water bills, and whether it happens during rainfall or when a particular fitting is used. Photos of the damage and accessible pipework are helpful.
Leaks found. Problem solved.
Tell us what you’ve noticed and your property’s postcode. We’ll confirm availability and the appropriate next step. Call 0203 576 5576.
