The short answer. A plumber repairs visible plumbing you can already see and reach. A leak detection specialist pinpoints a hidden leak first, behind walls or under floors, using non-invasive equipment, so any repair that follows is small and targeted rather than a guess. The two roles work hand in hand.
When water is coming up through the kitchen floor or a damp patch keeps spreading across a ceiling, most people reach for the phone and call a plumber. That is often the right instinct. But there is a moment, usually once the obvious checks come back clear, when the question changes from “how do we fix this” to “where on earth is the water actually coming from”. That is the line between a plumber and a leak detection specialist, and understanding it can save you a fair amount of money and a great deal of disruption.
This is not a case of one trade being better than the other. A good plumber is invaluable, and so is a good leak detection engineer. They simply solve different parts of the same problem. Here is how the two fit together, and how to tell which one you need first.
What a plumber does
A plumber installs, maintains and repairs the plumbing inside your home: taps, toilets, radiators, boilers, sinks, the pipework you can reach and the fittings that join it all together. When a leak is visible, a dripping joint under the sink, a failed seal on a washing machine, a radiator valve that has started weeping, a plumber is exactly who you want. They can see the fault, isolate the supply and put it right, often in a single visit.
Where it gets harder is when the water is showing up somewhere, but the source is hidden. A damp patch on a wall might be fed by a pipe running two metres away. Water pooling under a floor could be coming from a slab leak, a heating pipe, or even rain getting in from outside. A plumber can certainly fix the pipe once it is found. The challenge is finding it without lifting half the floor to look, and that is a different skill set entirely.
What a leak detection specialist does
A leak detection specialist does one thing extremely well: locating a hidden leak precisely, without tearing the property apart to find it. The job is diagnosis rather than repair. Using a combination of techniques, an engineer narrows the search down from “somewhere under this room” to a specific spot, often within a small margin, before anyone picks up a tool to open anything up.
The point of all this is to keep the eventual repair small. If you know the leak sits beneath one particular floor tile, you lift one tile. If you are guessing, you might lift the whole floor and still miss it. Specialist detection turns an open-ended, destructive search into a single, targeted opening, which is usually quicker, cheaper and far less stressful for the homeowner.
The main methods a specialist uses include:
- Acoustic listening equipment that picks up the faint sound of water escaping under pressure
- Thermal imaging cameras that read temperature differences on a surface to reveal warm or cold trails
- Tracer gas, a safe gas introduced into the pipe that rises to the surface at the exact leak point
- Moisture meters and damp mapping to follow how far water has tracked through a structure
No single method works for every leak, which is why a good engineer cross-checks one against another before marking the spot.
Why not just let a plumber go looking?
You can, and for a straightforward visible leak that is often the sensible route. The difficulty comes with concealed leaks. To find a hidden leak by eye, someone has to start opening things up: lifting floorboards, drilling into plaster, breaking out screed. If the first opening is in the wrong place, they open another, and the damage adds up quickly. The repair to the pipe might take twenty minutes; the making good afterwards can take far longer.
Specialist detection is built to avoid exactly that. By locating the leak before anything is disturbed, you swap an exploratory dig for a precise one. It is the difference between knowing where to look and hoping you have guessed right, and on a concealed leak that difference can be substantial.
Which one do you call first?
A simple rule of thumb helps here. If you can see the leak, or you know exactly which fitting has failed, a plumber is usually the right first call. If you can see the damage but not the source, a damp patch with no obvious cause, an unexplained drop in boiler pressure, a water bill that has crept up for no reason, or the sound of running water when every tap is off, that points towards leak detection first.
In practice the two often overlap. A homeowner calls a plumber, the plumber confirms the leak is hidden and recommends bringing in a specialist to find it. Once the spot is pinpointed, the repair can be carried out with confidence. We are happy to find the leak and then advise on the repair, and in many cases carry it out, so you are not left chasing two separate trades to put one problem right. You can read more about how we approach finding concealed leaks on our water leak detection page.
How insurance fits into the picture
Many home insurance policies include something called trace and access cover, which is worth knowing about before you spend anything. Broadly, it is designed to pay towards the cost of finding a hidden leak and reaching it, including putting right any damage caused while locating the source. What it typically does not cover is the repair of the leaking pipe itself, or the damage caused by the escaped water, such as ruined flooring. Cover and limits vary between policies, so it is always worth checking your own paperwork or asking your insurer directly before work begins.
This is another reason precise detection matters. A clear, documented location of the leak makes any claim far more straightforward, and keeps the access work, and therefore the cost, to a minimum. If your property is supplied by South West Water, it is also worth checking with them about responsibility for any pipework on the boundary, as the answer can affect who pays for what.
Two trades, one goal
It helps to think of leak detection and plumbing as two stages of the same job rather than rival services. Detection answers the where; plumbing handles the fix. When a leak is sitting out in the open, you may only need the second stage. When it is hidden, starting with the first stage protects your home from unnecessary damage and usually works out cheaper overall, because the repair is small and aimed at the right place from the start.
If you are not sure which you need, that is completely normal, and it is exactly the kind of thing we are happy to talk through. A quick conversation about what you are seeing is often enough to point you in the right direction, whether that turns out to be a plumber, a detection visit, or both. You can find more guidance in our articles, or see the areas we cover across Devon.
Frequently Asked Questions
It depends on the job. For a visible leak, a plumber alone is usually all you need. For a hidden leak, paying for detection first often works out cheaper overall, because it avoids the cost of lifting floors or opening walls in the wrong place. Costs vary by property and situation, so it is best to ask for a quote based on what you are dealing with.
Sometimes, but it often means opening up parts of the property to look, which can cause damage if the first guess is wrong. Specialist detection equipment is designed to pinpoint the source before anything is disturbed, so the repair can be kept small and targeted.
The aim of professional leak detection is to locate the leak with minimal disruption, using non-invasive methods such as acoustic listening, thermal imaging and tracer gas wherever possible. Any access needed afterwards can then be limited to the precise spot rather than a wide exploratory search.
We find the leak first and then advise you on the repair, and in many cases we can carry it out too. That saves you arranging two separate trades for one problem. If a specialist repair is needed that falls outside our scope, we will tell you clearly so you know your options.
Many policies include trace and access cover, which typically helps with the cost of finding and reaching a hidden leak, and making good the access afterwards. It usually does not cover the repair of the pipe itself or the water damage. Cover differs between policies, so check yours or ask your insurer before work starts.
Not sure who to call about your leak?
Tell us what you are seeing and we will help you work out the right next step. We locate hidden leaks precisely across Devon, with same-week appointments often available.