Leak Detection
In a loft building the stain on the ceiling and the hole in the pipe are often in different rooms. Opening up under the stain is how you end up with two holes.
Why the obvious spot is usually wrong
Water leaving a pipe follows the structure, not gravity alone. It runs along the top of a ceiling deck, tracks the underside of a joist, follows a conduit or a sleeve through a wall, and emerges at the first place it can get through. In the wide-open floor plates of a converted warehouse that first place can be a long way from the failure.
So the job is to find the pipe, not the stain. That is the whole difference between a targeted repair and a series of exploratory holes in someone's finished ceiling.
How we locate it
- Meter isolation. Shut things off progressively and watch the meter. It will not tell you where, but it establishes whether you have a supply leak at all, and which branch it is on.
- Acoustic. A pressurised pipe leaking under a floor or behind plaster makes a characteristic noise. Amplified and traced, it narrows the position to a manageable area.
- Thermal imaging. Wet material holds temperature differently from dry. Useful for mapping the extent of the spread, and very good at finding hot water leaks.
- Moisture metering. Systematic readings across a surface to find where the wet ends, which is often the opposite of what the visible staining suggests.
- Dye and isolation testing for waste-side leaks, where nothing is under pressure and acoustic methods have nothing to hear.
Supply leak or waste leak
Worth separating early because they behave differently and the responsibility often differs too.
| Supply | Under pressure all the time. Constant, gets worse, shows on the meter, and will not stop on its own |
|---|---|
| Waste | Only wet when something upstairs is used. Intermittent, often worst in the morning and evening, invisible on the meter |
| Neither | Condensation on cold lines, a failed shower pan or grout, a roof or facade issue. Common, and worth eliminating before opening anything |
Between two apartments
The awkward case. The leak is in one unit and the damage is in another, which makes it a question of access as much as plumbing. It is generally worth involving the managing agent early rather than late, because the diagnostic needs both apartments and the repair may well need a wall opened in the one that has no visible problem at all.
Turn off every fixture in the apartment, including anything on a timer. Note the meter reading, wait an hour, read it again. Movement with everything off means water is going somewhere.
Need this doing?
Call and describe the problem. You will get the price before anyone starts.