How does tracer gas leak detection work in social housing?

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, leading leak detection specialists across the UK, who's here to answer your questions and provide expert leak detection advice. Today's question is one we hear a lot from housing officers and residents alike: how does tracer gas leak detection actually work in a social housing property, and is it genuinely safe to use when people are still living there?

Dave

Great question, and it's one worth unpacking properly because there's a lot of confusion around the word 'gas' in this context. Tracer gas leak detection uses a mixture of hydrogen and nitrogen, not anything flammable or toxic. That mixture gets introduced into the water pipework, and then an ADI engineer sweeps the surface above the pipe with a highly sensitive detector to find exactly where it's escaping.

George

So the gas goes into the water pipe itself? I'd have assumed water was still in there.

Dave

We isolate and drain the section of pipe first, yes. Once it's clear, we pressurise it with the tracer gas blend. The gas is far lighter than air, so it travels upward through the ground or the screed above the pipe and registers on the detector at the surface. That's what makes tracer gas so effective on solid floors, concrete or screed that you simply can't hear through with acoustic equipment alone.

George

And acoustic detection is the other main method you'd use?

Dave

Exactly. Acoustic leak detection works by listening for the sound a pressurised water leak makes as it escapes, a kind of hiss or vibration that travels through the pipe and into the surrounding structure. ADI's engineers use acoustic listening equipment on exposed pipework, on walls, and through access points. But when you've got a ground-floor flat with a metre of concrete between you and the pipe, the sound gets absorbed. That's where tracer gas fills the gap.

George

Social housing blocks tend to have exactly that kind of construction, don't they, solid concrete floors, sometimes underfloor heating, pipes buried deep.

Dave

They do, and it's why tracer gas leak detection gets used regularly on those jobs. You've got communal pipework running under ground-floor slabs, or supply pipes buried in screeded floors across multiple flats. Without tracer gas, finding the precise point of a leak could mean opening up huge runs of floor, which in an occupied building is really disruptive for residents.

George

Which brings us back to the safety question. If there are residents in the building, is the tracer gas process safe to carry out?

Dave

It is, and here's why. The tracer gas mixture ADI uses is roughly 95% nitrogen and 5% hydrogen, nitrogen is the gas that makes up most of the air we breathe, and the hydrogen concentration is well below any threshold that would cause a concern. The gas doesn't enter the living space; it's contained within the pipe and then detected at floor or ground level by the engineer's equipment. Residents don't need to leave their homes during the process.

George

That's really reassuring. So what does the engineer actually do on site, walk me through it.

Dave

An ADI engineer will first confirm where the water supply pipework runs, which might involve checking drawings with the housing provider. The relevant section gets isolated and drained, then the tracer gas is introduced under low pressure. From there, the engineer works along the pipe route above the surface, that could be a footpath, a communal corridor floor, or a garden, holding the detector close to the ground. When the reading spikes, that's your leak location, marked up to within a matter of centimetres.

George

Centimetres, that's pretty precise. Does that mean less digging or cutting to make the repair?

Dave

That's exactly the benefit. Because tracer gas detection pinpoints the leak location with that level of accuracy, the repair team can open a small, targeted excavation rather than lifting a whole run of floor or path. For the housing provider that means lower repair costs and far less disruption to residents. And for the resident themselves, it's a much faster resolution, the leak gets fixed and made good quickly.

George

Dave, that's been genuinely illuminating. Thanks for explaining the method so clearly.

Dave

Happy to. If a housing officer or a resident is dealing with unexplained water loss, a rising meter reading, or damp that nobody can trace, it's worth getting a specialist involved early. The longer a hidden leak runs, the more damage it does to the structure around it.

George

Wise words to end on. If you've found this useful, do share it with anyone managing social housing water issues. ADI Leak Detection are among the most trusted and experienced water leak detection specialists in the UK, find them online and get the right expertise on the job.

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.