Claims Evidence
Tracer Gas Leak Detection London
Trace and access lines are challenged on one question more than any other: was the opening up reasonable given what was known when it was decided? That is the question tracer gas exists to answer well, because it is the method that produces a point on a surface rather than an area of suspicion, and a point is what keeps a hole small enough to defend.
Why tracer gas changes the access line
| Invoice line | How it is treated | When it is settled |
|---|---|---|
| Draining and charging the circuit | Part of the detection line, not an extra | Adds preparation time to the visit |
| Surface tracing to a single point | Detection line, fixed before attendance | Gas needs time to travel through screed |
| Recording what each method eliminated | Included, and it is what survives a query | Logged as the testing happens |
| Opening up at the traced point | Access line, and a point keeps it narrow | Quoted once the point is marked |
| Recommissioning the system afterwards | Stated separately from detection and repair | After the failure is exposed |
Fee basis, not a quote, and not a statement of what your own policy covers. Our detection figure is fixed and confirmed in writing before anyone travels.
The mix is hydrogen and nitrogen, inert, and light enough to travel up through screed, tile and floor construction to a detector at the surface. The circuit has to be drained and charged first, which takes time, and the gas has to be given time to travel. Rushing either produces a vague result, which defeats the purpose of choosing the method at all.
We reach for it on screeded floors, long buried runs and plastic pipework where sound goes nowhere. What goes in the report is the point it surfaced, the conditions at the time, and what the other methods had already eliminated before we got there, because a single point with no context behind it is as queryable as no point at all.
One fixed detection figure covering the drain down, the charge, the trace and the written findings, agreed before attendance. Opening up at the marked point, repairing the failure and recommissioning afterwards are quoted as separate lines.
What you get
- Certified Methodology: Our use of tracer gas follows industry-standard, certified procedures that insurers recognise and accept as valid evidence.
- Non-Invasive Precision: We accurately locate leaks behind plaster, under concrete slabs, and within cavities without unnecessary destructive searching.
- Comprehensive Digital Report: We provide a detailed report with photos, gas concentration readings, and a clear conclusion on leak source and pathway.
- Evidence for Cost Recovery: Our findings directly support the justification for necessary remedial works, aiding in the recovery of both detection and repair costs.
- Swift Mobilisation: We prioritise emergency leak detection across London to prevent further damage and begin the claims evidence-gathering process promptly.
- Insurance-Focused Documentation: Every stage is recorded to create a clear audit trail from detection to report, satisfying insurer due diligence requirements.
How it works
A method, not a guess
01
Eliminate before charging
The circuits and systems already cleared by pressure testing and other methods are logged first. Tracer gas is the method that decides, and what it decided between has to be on the file for the decision to mean anything.
02
Drain and charge properly
The suspect circuit is drained and charged with the inert mix at controlled pressure. That preparation is inside the fixed fee rather than added afterwards, so nobody is choosing between doing it properly and watching the clock.
03
Let the gas travel
Through screed and tile this takes time, and a detector swept too early gives a diffuse reading that narrows nothing. The wait is planned into the visit, because the whole value of the method is the precision at the end of it.
04
Mark the point and photograph it
The surface point is marked physically and referenced to something findable in the room, then photographed before any opening. That image is what the proportionality of the access is argued from later.
Six questions worth asking before a tracer gas survey
What had already been eliminated before the gas went in?
Tracer gas is the method that decides, and a decision only means something if the file shows what it decided between. A report saying gas surfaced at a point in the kitchen, with no record of the circuits that were pressure tested and held first, has produced an answer with no reasoning attached. The version that survives scrutiny lists what was cleared, by what test, before the gas was introduced. It costs nothing to log at the time and it is the first thing requested when somebody questions why one area was opened and not another.
Was the circuit properly drained and charged?
Gas cannot travel through a system full of water, and a circuit half drained gives a diffuse result that narrows an area rather than fixing a point. The preparation is the unglamorous part of the method and it is the part most often rushed when a visit is running behind. Ask whether the drain down and the charge are inside the quoted fee or billed as extra time, because a contractor who is being paid by the hour to do a slow preparation step is under exactly the wrong incentive.
Was the gas given time to reach the surface?
Through a screed floor with a tiled finish, the mix needs time to work its way up through the construction. Sweeping a detector across the floor too early produces a weak reading in several places, which narrows nothing and often gets written up as though it narrowed something. The visits that produce a usable point are the ones where the waiting time was planned into the day. If a contractor quotes a tracer gas survey at an hour on a screeded floor, ask how the timing is going to work.
Is the safety position set out in writing?
The industry mix is hydrogen in nitrogen at a concentration well below anything flammable, non toxic and leaving no residue. Most engineers will tell you that on the doorstep. Fewer put it in the report, and in a flat or a managed building somebody who will never meet you has to approve works they will not witness. A paragraph stating the mix used and why it is safe in occupied property turns a phone call with a managing agent into a signature, which is often the difference between starting this week and starting next month.
What happens if the gas surfaces in more than one place?
It is not unusual, and it is informative rather than embarrassing. Multiple surfacing points generally mean either more than one failure or a single failure with water tracking along a void before escaping. The right response is to record every point with its position and say which is most consistent with the pressure testing and the moisture readings. The wrong response, and the one that causes trouble later, is to pick the most convenient point and present it as a single confident finding.
Who is paying for the recommissioning?
Draining a heating circuit means refilling it, rebalancing it and in most cases dosing with inhibitor afterwards. Those are routine maintenance items, policies generally exclude them, and folding them into a detection figure does not get them paid. It gets the detection figure queried while the part that would have been settled waits behind it. Ask for recommissioning to be quoted as its own line before the visit, so nobody is surprised by it and nothing else on the invoice is contaminated by it.
Compare like for like
The method that keeps the access line small
Tracer gas earns its place on the jobs where nothing else will commit: screeded floors, long buried runs, plastic pipe that swallows sound. Its value to a claim is specific. It produces a point rather than a zone, and a point is what keeps the opening up narrow enough to defend when the trace and access line is examined.
| What to check | A one line invoice | A listen only firm | Emergency Leak Detection 247 |
|---|---|---|---|
| Zone or point | A zone at best, and the opening up is then sized to the uncertainty rather than to the leak. | A zone on plastic and under screed, because that is where acoustic methods lose the signal. | A marked point on the surface where the gas emerges, which is the difference between lifting two boards and lifting a room. |
| Preparation and drain down | Skipped, and the survey proceeds on whatever the system happens to be doing. | Not applicable to their method, which is part of why the method stops short here. | The circuit is drained and charged properly, and the preparation time is inside the fixed detection fee rather than added to it afterwards. |
| What gets recorded | The result. Nothing about the sequence that produced it. | The acoustic findings, with the inconclusive ones often left out. | What each method eliminated and in what order, because the eliminations are what an adjuster asks for when a claim stalls. |
| Safety framing in the report | Unaddressed, which becomes awkward in a block where a managing agent has to approve the works. | Not relevant to them, so not covered. | The inert hydrogen nitrogen mix used, and why it is safe around occupied property, is stated plainly so a managing agent can sign it off without a call. |
| Time allowed for the trace | Whatever the visit runs to, with the clock running. | Short, because sound is immediate and the trade off is accuracy through screed. | Gas needs time to travel through screed and tile. That time is built into the fixed fee, so nobody is deciding between accuracy and the clock. |
| How it appears on the invoice | One figure. Detection, access and repair are indistinguishable, so the covered element cannot be paid on its own. | A detection fee, which is clean, followed by somebody else's repair invoice that may describe the failure differently. | Detection, access, repair and making good on separate lines, described consistently, so the file reads as one account of one failure. |
| If nothing is found | You pay for the time spent and are told to try again. | Occasionally waived, and most often not waived in exactly the cases where the method could not see the leak. | Where we attend a confirmed live loss and cannot locate it, the detection fee is waived and you keep the full record of what was tested and cleared. |
What claimants ask
The questions policyholders and agents ask most
Tracer gas comes up on the DIY and housing discussions mainly in two situations: somebody has been quoted for it and wants to know whether it is worth the money, or somebody has had every other method fail. The replies from people who have been through the second situation are usually the more useful ones.
Posters who paid twice because the first method could not commit
A common sequence on the public discussion. An acoustic survey narrows a screeded floor to a general area, a floor is opened on that basis, nothing is found, and a gas survey is then booked. The regulars point out that the cheaper first visit was not cheaper. Our take is that the method should be chosen for the construction rather than for the price list, which is why we ask about floor build up and pipe material at booking rather than turning up with one technique and hoping.
Worry about introducing gas into a home
A recurring anxiety, and a reasonable one to raise. The discussions settle quickly once someone explains the mix is mostly nitrogen with a small hydrogen fraction, non toxic and below the flammable range. Our take is that the reassurance belongs in the written report rather than only in conversation, because in a leasehold flat the person who has to be satisfied is often a managing agent who was never in the room and will not take a verbal account of it.
Arguments about how big the hole needed to be
Reinstatement disputes are a constant, and they turn on the precision of what preceded them. Forum advice increasingly tells people to ask what location accuracy the method produces before agreeing to any breaking out. Our position is that this is exactly the right question, and it is why gas is used where precision matters, since a marked surface point supports a small opening in a way that a suspected area never does.
Confusion about what happens to the heating afterwards
Threads where somebody was surprised by a refill and inhibitor charge, or found their system noisy and unbalanced after a detection visit. The advice is to agree the recommissioning before the drain down. We quote it separately as a matter of course and describe it as maintenance, because it is, and because an insurer looking at a mixed line tends to query the whole line rather than the part that bothered them.
People asking whether the result is admissible for a claim
A frequent question phrased in various ways, usually meaning whether an insurer will accept a gas finding. The replies are consistent that the method is not the issue, the documentation is. Our take matches that. What makes a tracer gas finding usable is the record of what was eliminated first, the position of the surfacing point referenced to something findable, the photograph taken before anything was opened, and a plain statement of what the survey did not establish.
Questions
Asked before every booking
Is the gas safe in an occupied flat or a managed block?
The mix is hydrogen in nitrogen at a concentration well below anything flammable, it is non toxic, and it disperses without residue. That is worth stating in writing rather than just saying, because in a managed building somebody has to approve works they will not be present for. Our report sets out the mix used and why it is safe in occupied property, so a managing agent or a freeholder can sign it off without ringing us.
Why is tracer gas chosen when acoustic detection is quicker?
Because on some constructions acoustic detection does not commit. Plastic pipe absorbs the frequencies the method relies on, deep screed muffles what is left, and a long buried run under a driveway can give a signal that narrows a stretch without fixing a spot. Gas does not care about the acoustics. It travels to the surface at the point of escape. On a claim that difference shows up directly in how much floor had to come up.
Does the system have to be drained?
Yes, for the circuit being tested, and that is worth knowing in advance because it affects the visit. A heating circuit will need refilling, rebalancing and in most cases inhibitor afterwards. We quote that as a separate line and describe it as maintenance, because wordings routinely exclude maintenance and burying it inside a detection fee is a good way to have the detection fee queried.
What if the gas surfaces in more than one place?
Then the report says so, and that is genuinely useful information rather than a failure. Multiple points usually mean either more than one failure or a single failure with water tracking along a void before it escapes. Either way the correct response is to record all of them with their positions and say which is most consistent with the other evidence, not to pick the convenient one and present it as certain.
Will the marked point survive until the repair happens?
We mark it physically and reference it to fixed features in the room, and we photograph both, so the point can be re established if there is a gap before the opening up. That matters when an insurer wants to inspect before work starts, or when a managing agent has to arrange access, because a mark that only exists in somebody's memory is not evidence of anything.
How does tracer gas leak detection work?
The suspect circuit is drained and charged with an inert mix of hydrogen and nitrogen. The mix is lighter than air and small enough in molecule to pass through screed, tile, grout and floor construction, so it rises from the point where the pipe has failed and emerges at the surface. A sensitive detector is then swept methodically across the floor to find where the concentration peaks. The result is a point rather than an area, which is why the method is chosen when precision is what matters.
When is tracer gas better than acoustic or thermal methods?
On plastic pipework, which absorbs the frequencies acoustic detection relies on. Under deep screed, where sound is muffled and thermal patterns are slow and diffuse. On long buried external runs, where correlation narrows a stretch but rarely fixes a point. And on cold water circuits with no temperature differential for a camera to read. The honest way to put it is that gas is the method that works when the construction has defeated the quicker ones.
Is tracer gas safe around children, pets and occupied flats?
The mix used in this work is overwhelmingly nitrogen with a small hydrogen fraction, well below the concentration at which hydrogen becomes flammable. It is non toxic, it leaves no residue and it disperses on its own. It is introduced into a drained pipe rather than released into the room. We set out the mix and the safety position in the written report so that a managing agent, a freeholder or a landlord can satisfy themselves without needing a conversation with us.
How long does a tracer gas survey take?
Longer than the alternatives, and that is intrinsic to the method. Draining the circuit takes time, charging it takes time, and the gas needs time to travel through the construction to the surface. Most domestic surveys sit within a working day. Deep screed, stone finishes and long external runs can take longer, and we would rather build that into the plan than sweep a detector across a floor before the gas has arrived and call the result a location.
Will a tracer gas report be accepted for a trace and access claim?
The method is well established and is not usually the point of difficulty. What determines whether a report is accepted is whether it states the mechanism of failure, references the location to something a stranger can find, records what was tested and eliminated, contains dated photographs covering the area before access and the failure in position, and says explicitly what the evidence does not establish. We write to that standard. What no report can do is guarantee payment, because the decision belongs to your insurer under your wording.
What if the gas does not surface anywhere?
Then either the circuit tested is not the one that has failed, or the escape is somewhere the gas cannot reach the surface from, and the report says which of those is more likely and why. A negative gas result on a properly charged circuit is a meaningful elimination and it narrows the search for whoever continues it. Where we attend a confirmed live loss and cannot locate it, the detection fee is waived and you keep the complete record of what was tested.
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Covering all 33 boroughs
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