What can acoustic leak detection confirm or rule out in a concealed pipe leak?

Full transcript

George and Dave in conversation. Every word of the episode, exactly as recorded.

George

Welcome to the ADI Leak Detection podcast. I'm here with Dave from ADI Leak Detection, the country's leading name in leak detection, who's here to answer your questions and provide expert leak detection advice. Dave, today's question comes from homeowners who've been told they might have a concealed pipe leak but aren't sure what the investigation actually involves. So let's start at the beginning: what does acoustic leak detection actually do?

Dave

Acoustic leak detection picks up the sound and vibration that a pressurised leak creates as water forces its way through a breach and into the surrounding material. The pipe doesn't have to be visible. As long as it's under pressure, it's producing a signal, and our listening equipment reads that signal through the floor surface or the wall above it.

George

So the leak has to be active for this to work? You can't detect an old, dry crack?

Dave

Exactly right. Acoustic listening needs an active, pressurised leak to give us anything useful. A pipe that cracked six months ago and has since equalised won't produce that sound signature. That's one of the first things the method rules out, actually. If we're getting no acoustic signal on a live pressurised system, it tells us either the leak is extremely slow, or the escaping water is tracking somewhere that dampens the sound before it reaches the surface.

George

And what does a clear positive result look like? How do you know you've found it?

Dave

The signal peaks directly over the breach. ADI's engineers walk the listening device along the pipe run, and the sound intensity rises as you approach the leak point and drops away as you move past it. On a solid concrete floor with a copper supply pipe running below, that peak is often very sharp. You can get to within a few centimetres.

George

What makes it harder? Because I'd imagine not every house has a nice, simple concrete floor.

Dave

Background noise is the main complication. A busy road outside, a boiler running, even a washing machine on the other side of the wall can all mask the frequency we're listening for. Timber suspended floors add another layer because the wood absorbs and scatters the vibration rather than transmitting it cleanly. In those situations, acoustic listening narrows the search area rather than pinpointing to a single spot.

George

So it rules things in, but it can also rule things out. Can you give me an example of a case where acoustic detection ruled something out completely?

Dave

A good one is when a homeowner has damp appearing at a specific point and assumes the supply pipe beneath that spot is leaking. We listen across the whole pipe run and get nothing, no acoustic signature anywhere on that supply. That tells us the water source isn't a pressurised pipe leak at all. We're then looking at a drainage issue, a condensation problem, or water tracking from somewhere else entirely. Without that acoustic check, a lot of unnecessary excavation can happen.

George

That's a really useful distinction. So it's not just about finding the leak, it's about not digging in the wrong place.

Dave

That's exactly how ADI's engineers think about it. Every method we use is as much about ruling out locations as confirming them. Acoustic listening on a pressurised cold supply pipe is very reliable for an active breach. Where it has limits, we bring in tracer gas or pressure testing to fill the gaps.

George

How does pressure testing fit alongside the acoustic work?

Dave

Pressure testing confirms there is a loss happening somewhere on the system before we start listening. If the pressure holds steady, there's no active leak on that pipe run, and acoustic detection will tell you nothing useful. Pressure testing and acoustic listening used together mean we never spend time searching acoustically on a system that isn't losing water.

George

What about property type? Does it matter whether it's a Victorian terrace versus a modern new-build?

Dave

It matters quite a bit. Older properties often have longer, more complex pipe runs, sometimes running under quarry tiles or original flagstones, which can actually transmit sound surprisingly well. New-builds tend to have plastic pipework, and plastic leaks produce a weaker acoustic signature than copper or iron. The signal is still there, but it's quieter, so our engineers need to work more carefully and may rely more on tracer gas alongside the acoustic survey.

George

Dave, that's been really clear. Before we close, is there a simple way for a homeowner to think about what acoustic detection is for?

Dave

Think of it this way: acoustic leak detection answers the question of whether an active pressurised leak exists and, if it does, roughly or precisely where it is. It doesn't tell you about slow seepage below detection threshold, or drainage failures, or condensation. But paired with pressure testing and tracer gas, ADI's engineers can build a complete picture of what's happening under any floor or inside any wall without unnecessary damage to the property.

George

That's a great place to leave it. Thanks, Dave. And if you've got a suspected concealed leak at home, ADI Leak Detection is among the most trusted names in the field for this kind of specialist investigation. We'll be back with more answers to your real-world questions very soon.

How this episode was made. This episode was produced using AI-generated voices and script, based on real leak detection questions and the working knowledge of ADI Leak Detection engineers.