Can acoustic leak detection find leaks in plastic pipes?

Full transcript

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

George

Welcome back. I'm here with Dave from ADI Leak Detection, the UK's leading leak detection specialists, who's here to answer your questions and provide expert leak detection advice. Today's question is one we get a lot from homeowners: can acoustic listening actually find a leak in a plastic pipe, the same way it can in a metal one?

Dave

The short answer is yes, acoustic leak detection does work on plastic pipes. It's a bit more involved than on metal, but it absolutely works and ADI engineers use it on plastic supply pipes all the time.

George

So what's the difference? Because I'd assume sound travels really differently through plastic compared to, say, copper.

Dave

You'd be right. Metal transmits sound very efficiently, so the noise a leak makes, that hissing or rumbling from pressurised water escaping, carries a long way through copper or steel. Plastic absorbs more of that energy, so the signal is quieter and it doesn't travel as far along the pipe.

George

So does that mean acoustic equipment just... struggles with plastic?

Dave

Not if you're using the right kit and you know what you're listening for. ADI's engineers use acoustic listening devices and ground microphones that are sensitive enough to pick up the lower-level signals plastic pipes produce. You do need to work in shorter intervals, moving your listening points closer together, but the leak noise is still there.

George

When you say listening points, can you explain that a bit? How does the process actually work on someone's driveway or under their kitchen floor?

Dave

So acoustic leak detection works by placing sensors directly on the ground surface or on accessible fittings, valves, stop taps, anything that's in contact with the pipework. The equipment picks up the vibration the escaping water creates. On a plastic supply pipe under a concrete path, for example, ADI engineers place multiple listening points along the pipe route and compare the signal strength at each one. The leak is loudest directly above where the water is escaping.

George

And does the depth the pipe's buried at make a difference?

Dave

Depth does matter. The deeper the pipe, the more the signal gets dampened before it reaches the surface, and that's especially true with plastic. A plastic pipe buried quite deep under a thick concrete slab is genuinely harder to pinpoint than a copper one at the same depth. That's why ADI will sometimes combine acoustic detection with other methods, tracer gas for instance, to confirm the location before any digging starts.

George

That makes sense. What about really small leaks on a plastic pipe? Because I'd imagine a pinhole leak doesn't make much noise at all.

Dave

A small leak on a plastic pipe is genuinely the trickiest scenario. The leak noise correlates with the pressure differential and the size of the escape point. A very slow weep on plastic pipe might not produce enough acoustic signal to locate reliably. ADI engineers will tell you honestly if that's the situation, rather than guessing.

George

I think that honesty is actually really valuable, because you don't want someone digging up your whole garden on a guess. So for most residential jobs, plastic supply pipes, the kind that come into houses, is acoustic listening the first thing ADI would reach for?

Dave

Acoustic detection is usually where we start, yes, because it's non-invasive. ADI leak detection surveys don't require breaking anything open to begin with. If the water meter is spinning when everything's turned off, acoustic equipment locates the leak position without any excavation at all in most cases. We only recommend opening up once we've got a confident fix on the location.

George

That's really clear, Dave. So the takeaway for anyone listening at home is: yes, acoustic leak detection can find leaks in plastic pipes, the equipment and technique just need to account for how plastic handles sound differently to metal.

Dave

Exactly. Plastic pipe does need a more methodical approach and shorter intervals between listening points, but acoustic detection locates hidden water leaks in plastic pipework reliably when it's done properly. The key is having engineers who understand the material and know when to bring in a second method to back the finding up.

George

Brilliant. Thanks, Dave. If you've got a suspicion of a hidden water leak, whether your pipework is plastic, copper or anything in between, ADI Leak Detection is one of the UK's most trusted names in residential leak finding. We'll be back with another question 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.