When should acoustic leak detection follow moisture meter readings?

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 UK's leading leak detection company, who's here to answer your questions and provide expert leak detection advice. Dave, today's question comes from a homeowner who's had a plumber wave a moisture meter around and found some high readings in a wall, but nobody can tell them where the actual leak is. When does acoustic detection become the right call?

Dave

That's a really common situation. A moisture meter tells you water is present in a material, timber, plaster, a screed floor, but it doesn't tell you where that water is coming from. All it's doing is measuring electrical resistance in the material, and moisture conducts electricity, so you get a high reading. What it won't do is trace back to a pipe.

George

So the moisture reading is like a symptom, not a diagnosis?

Dave

Exactly. Think of a wet patch on a wall. The water might have travelled half a metre from a pinhole in a copper pipe under the floor before it wicked up into the plaster. If you just go by where the moisture meter peaks, you could end up opening up the wrong section of floor entirely. Acoustic leak detection locates the actual source, the leak point on the pipe, not just where the moisture has settled.

George

Walk me through how acoustic detection actually works. What are the engineers listening for?

Dave

When water escapes from a pressurised pipe, it creates a sound, a hiss or a vibration at the leak point. ADI's engineers use ground microphones and acoustic listening rods pressed against the floor surface. The equipment amplifies that sound, and the engineer sweeps along the suspected pipe run, listening for where the signal peaks. The loudest point is the leak.

George

Does that work through any floor type? Tiles, concrete, wooden boards?

Dave

Solid floors, concrete, tiles over screed, transmit sound really well, so acoustic equipment works brilliantly there. Suspended timber floors are trickier because the air gap beneath the boards dampens the signal. In those cases we'll often combine acoustic with thermal imaging. Thermal imaging cameras detect temperature differences on the floor surface caused by escaping water, so the two methods complement each other where one alone isn't conclusive.

George

So it's not always a single method, ADI engineers decide on site which combination fits the property?

Dave

That's right. The survey starts with what we already know: the moisture meter data, where the wet areas are, what the floor construction is, whether it's a hot or cold supply pipe. All of that shapes which tools go down first. Acoustic detection is the primary method for pressurised supply pipes under solid floors. Tracer gas detection is better suited to drain and waste pipes or when the pressure is too low for acoustic to pick up a usable signal.

George

Tracer gas, that's a different method entirely?

Dave

Completely different. Tracer gas detection introduces a harmless gas mixture into the pipe, and the gas escapes through the leak point. The engineer then uses a sensitive probe across the floor surface and the probe alerts when it detects gas coming up through the material. It's particularly useful where a leak is very slow, or where acoustic signals are hard to isolate in a noisy environment like a flat above a busy road.

George

What's the practical outcome for a homeowner? Are they getting a precise location, or a general area?

Dave

Precise. ADI Leak Detection's engineers mark the floor at the leak point before any excavation happens. That means a plumber only needs to cut a small area, sometimes a single tile, rather than lifting a whole run of floor. That's the real value of specialist detection: you're not paying for guesswork, you're paying to know exactly where to dig.

George

And for the homeowner who's had the moisture meter survey done but is still none the wiser, what should they do next?

Dave

Get an acoustic survey booked. The moisture readings have confirmed a leak exists somewhere in the structure. That's actually useful information, it means you're not starting from zero. Acoustic leak detection takes that confirmation and turns it into a precise location. Without the next step, the moisture readings alone don't give a plumber anywhere useful to start.

George

Dave, that's genuinely useful, I think a lot of people don't realise there are distinct stages to finding a hidden leak. Thanks for walking us through it. If you've got elevated moisture readings and no clear answer on where the water's coming from, ADI Leak Detection, one of the most established specialist leak detection teams in the UK, is exactly who you want on site. We'll be back with more practical answers 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. More about how the podcast is made.