In This Guide
What does trace and access mean?
Trace and access is the term used for finding a water leak you cannot see and getting to it so it can be repaired. It is used both by plumbers describing the work and by insurers describing a section of a buildings policy, which is why the phrase turns up in two quite different contexts.
The name is literal. Trace means locating the leak, narrowing it down from a damp patch or a moving water meter to a specific point in the pipework. Access means opening up whatever sits between you and that point, whether that is floorboards, tiles, plaster or ground outside.
The reason it exists as a named service at all is that on a hidden leak the finding is usually the hard part. Once a failed pipe is exposed, repairing it is often quick and inexpensive. Getting to it without demolishing half a room is the skilled work, and that is what trace and access describes.
Why is it called trace and access?
Splitting the term in two reflects how the job is actually carried out and, on an insurance claim, how the costs are assessed.
The trace stage is investigative and non-invasive. Nothing is opened up. The engineer works across the surface with detection equipment until the leak is pinpointed, ideally to within a few centimetres.
The access stage is physical. Once the location is confirmed, the engineer opens up that specific spot and no more. The order matters: tracing accurately first is what keeps the access work small. Opening up speculatively and hoping to find the leak is how a small job becomes a large one.
How does trace and access work?
A typical investigation runs in this order.
First, the engineer confirms a leak is actually present and gathers the evidence. That usually means checking the water meter, looking at where damp is showing, and asking what has changed recently. If you want to do this part yourself before calling anyone, our guide to tracking and tracing a water leak covers the water meter test.
Second, the area is narrowed down. Moisture mapping across walls and floors shows where water is present and, more usefully, where the concentration is highest, which is normally closest to the source.
Third, the leak is pinpointed with the appropriate equipment for the situation, which is covered in the next section.
Fourth, the access work is carried out at the confirmed point, taking up the minimum floor, wall or ceiling needed to expose the failure.
Fifth, the findings are documented. On an insurance job this written report is as important as the work itself, since it is what the insurer assesses the claim against.
The repair itself is a separate job that follows, and so is putting the room back to how it looked. Trace and access covers finding the leak and reaching it, not fixing it.
Do not simply redecorate over water stains or damp patches. Painting over a damp wall without fixing the source will result in the stain reappearing within weeks.
What equipment is used to trace a leak?
Method | What it does | Best suited to |
Thermal imaging | Reads temperature differences across a surface, so a hot pipe shows against a cold floor | Heating pipes, underfloor heating, hot supply leaks in walls and ceilings |
Acoustic detection | Amplifies the sound of water escaping a pressurised pipe | Supply pipes, leaks under concrete or paving, underground runs |
Tracer gas | A safe inert gas is put into the pipe and detected where it surfaces | Underground pipes, leaks under screed or slab where sound carries poorly |
Moisture meters | Measure water content in building materials | Mapping how far damp has spread and finding the wettest point |
No single method suits every leak, which is why an investigation usually combines two or three. A thermal camera might show a warm area in a wall, acoustic testing then confirms whether a pressurised pipe is behind it, and a moisture meter maps how far the water has tracked. Reading those results together is what separates an accurate trace from a guess.
How long does trace and access take?
Most straightforward domestic leaks are located within a single visit. A leak in an accessible position with clear symptoms can be pinpointed in an hour or two.
Complex cases take longer. Underground supply pipes, leaks under solid floors, intermittent leaks that only show when the heating runs, and leaks affecting more than one property all extend the work. A leak that only appears intermittently is the most awkward of all, because the conditions that cause it have to be recreated before it can be traced.
The access work afterwards depends entirely on what sits over the leak. Lifting a floorboard is quick, cutting a tiled floor is not.
Don’t mask it — find it
Air fresheners and dehumidifiers do not address water that is continuing to leak into the structure. Investigate the plumbing, don’t cover up the smell.
Trace and access on an insurance claim
Trace and access is also the name of a benefit in most UK buildings insurance policies, which pays for exactly this work. That is why people often come across the term while reading their policy rather than while dealing with a leak.
The short version is that the benefit pays to find the leak and reach it, and usually to make good the area opened up, but not to repair the pipe or put right the water damage. Limits, exclusions and how to check whether you have it are covered in full in our guide to trace and access cover. If you want to know what the work costs without insurance, our guide to how much trace and access costs sets out current market ranges.
Who carries out trace and access work?
This is specialist work rather than general plumbing. It needs the detection equipment, the experience to interpret what that equipment shows, and the ability to produce a report an insurer will accept. A general plumber with basic tools can find an obvious leak, but a hidden one is a different job. Our guide to who carries out trace and access work covers what to look for, and our step by step guide to a trace and access inspection walks through what happens on the day.
How 0800 Homefix carries out trace and access
0800 Homefix carries out trace and access across London and the South East. We locate the leak using acoustic detection, thermal imaging, tracer gas and moisture meters before anything is opened up, keep the access work to the minimum the repair requires, and produce a written report documenting the method, findings and photographs.
We charge the first hour’s labour in advance, with any further investigation or access work quoted and agreed with you before it begins. Current rates are on our rates page. Our labour is guaranteed for 12 months, and any manufacturer part we fit carries the manufacturer’s own 12-month guarantee. We work seven days a week, 365 days a year. You can read more on our trace and access service page.
Helpful resources
WaterSafe maintains the national register of approved plumbers for work on water supply pipes. The Association of British Insurers publishes guidance on what buildings insurance policies typically cover.
Frequently Asked Questions
What does trace and access mean in plumbing?
It means finding a hidden water leak and opening up the floor, wall or ceiling to reach it so it can be repaired. Trace is locating the leak with detection equipment, access is exposing it. The repair itself is a separate job.
What is the difference between trace and access?
Trace is the investigation, locating the leak without opening anything up, using thermal imaging, acoustic equipment, tracer gas and moisture meters. Access is the physical work of removing floor, wall or ceiling material at the confirmed point to expose the pipe.
How does trace and access work?
A reset only clears the code, it does not repair anything. If F2 comes straight back, something is still stopping a stable flame, most often a dirty flame-sensing electrode, a faulty gas valve, or a fan or flue fault. These need an engineer to diagnose and fix.
How long does trace and access take?
Most straightforward domestic leaks are located within a single visit, often in an hour or two. Underground pipes, solid floors, intermittent leaks and leaks affecting more than one property take longer, and the access work depends on what covers the leak.
Does trace and access include repairing the leak?
No. Trace and access covers finding the leak and exposing it. Repairing the pipe and putting right any water damage are separate pieces of work, and on an insurance claim they sit under different sections of the policy.
Can trace and access find a leak under a concrete floor?
Yes. Acoustic detection can pick up water escaping a pressurised pipe through solid concrete, and tracer gas can locate leaks beneath a slab or screed where sound does not carry well. Both avoid breaking up the floor to search.
Think You Have a Hidden Leak?
If you have damp patches, a rising water bill or a meter that moves with everything switched off, the sooner the leak is traced the smaller the repair. 0800 Homefix locates hidden leaks across London and the South East before anything is opened up, seven days a week. Book online or through our trace and access page to arrange an inspection.
Spotted Any of These Warning Signs?
Our leak detection specialists cover London and the South East using acoustic detection, thermal imaging and moisture meters — no unnecessary damage, full written report, available 7 days a week.
Editorial note: This article is intended as a general homeowner guide. All plumbing work on supply pipes should be carried out by a qualified, WaterSafe-registered plumber. If you suspect a gas leak, leave the property immediately and call the National Gas Emergency Service on 0800 111 999.
