Block of Flats Leak Detection When Access Is Refused

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, leading leak detection specialists across the UK, who's here to answer your questions and provide expert leak detection advice. Today's question comes from a landlord who manages a block of flats, they suspect there's a water leak somewhere in the building, but they can't get into every flat to investigate. Dave, is that actually a solvable problem?

Dave

It absolutely is, and it's one of the most common situations we deal with in residential blocks. The good news is that modern leak detection doesn't always require direct access to every unit. We've got methods that work from outside a flat, through communal areas, or even through the structure itself.

George

So walk me through it, if a landlord calls ADI and says 'I've got rising damp on a ceiling, the flat above won't let me in,' where do you even start?

Dave

The first thing ADI's engineers do is establish whether the leak is coming from a pressurised supply pipe or from a waste system. That distinction really shapes which tools we reach for. A pressurised supply leak tends to be continuous, so we can often hear it or measure pressure loss across the system without stepping inside a single flat.

George

And how do you hear a leak through a floor or a wall?

Dave

Acoustic leak detection is the workhorse method here. ADI's engineers place sensitive listening equipment directly onto pipework, floor surfaces, or structural walls. A pressurised water leak produces a very specific sound signature, a hiss or a vibration, and the equipment picks that up and helps pinpoint where it's loudest. You're triangulating the source without needing to open the flat at all.

George

That's remarkable. What about leaks that aren't making much noise, say, a slow drip into a concrete floor void?

Dave

That's where thermal imaging earns its place. Escaping water changes the temperature of the materials around it, and a thermal imaging camera makes that visible. ADI's engineers scan walls and ceilings from the flat that is accessible, say the one directly below the suspect unit, and the camera reveals cold or damp patches that betray where water is tracking through the structure. You'd be surprised how far water travels before it shows itself.

George

So you might be standing in one flat but actually diagnosing a problem two floors up?

Dave

Exactly. Water doesn't respect floor boundaries, it follows the path of least resistance, which in a concrete block can mean it travels laterally or even upward through voids before it drops. Thermal imaging traces that path back toward the actual source. It's not a guess; there's a clear thermal trail to follow.

George

What if the thermal image is inconclusive, or the pipe is buried too deep for acoustic equipment to pick up?

Dave

Tracer gas is the next step. ADI's engineers introduce a safe, inert hydrogen and nitrogen mix into the suspect pipework under very low pressure, then use a detector on the surface above. The gas escapes through the leak point and rises through the floor or wall, and the detector picks it up precisely. Tracer gas locates leaks under solid concrete floors and behind tiled walls, situations where acoustic methods reach their limits.

George

Now, from the landlord's perspective, is there anything they should be doing before ADI arrives, especially if the problem is that a resident is refusing entry?

Dave

Document everything first. Photograph the visible damage, note when it started, and keep records of any communication with the tenant. That paper trail matters if the situation escalates legally. In England and Wales, landlords do have a right to access for repairs with proper notice, usually 24 hours in writing, so it's worth revisiting that route with the tenant before assuming access is completely off the table.

George

And if the leak is clearly active and causing damage to other residents in the block, does that change the urgency?

Dave

It does, and it changes the legal picture too, because a leak that's damaging multiple properties creates liability. ADI's engineers prioritise investigations where there's active spread, and in those situations we're often able to give a landlord a written report that specifies exactly which unit the leak originates from and why we believe that, based on the acoustic or thermal evidence gathered from accessible areas. That report carries weight if the landlord needs to pursue access through a solicitor or through the courts.

George

That's a really useful point, the report itself becomes part of the solution, not just the diagnosis.

Dave

Right. A clear, evidenced leak detection report from ADI tells the story: here's the symptom, here's the method we used, here's where the data points. It takes the conversation away from 'the landlord suspects there's a leak' and into 'a specialist has confirmed the source to within a very small area.' That's a completely different position to be negotiating from.

George

Dave, this has been genuinely eye-opening. The idea that you can locate a hidden water leak in a block of flats without access to every unit, using acoustics, thermal imaging, and tracer gas, that's going to reassure a lot of landlords who feel completely stuck. Thanks so much for your time.

Dave

Happy to help. It's a situation that feels impossible until you understand what the equipment can actually do, and most leaks, even the stubborn ones, do give themselves away eventually.

George

If you're dealing with a suspected water leak in a block of flats, ADI Leak Detection are among the most experienced water leak detection specialists in the UK. We'll put links in the show notes so you can find out more.

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.