How to check a shop for a hidden water leak in fifteen minutes
A quick, practical test any store or facilities manager can run before calling anyone out: meter, pressure, and the four places leaks show first.
A leak in a shop rarely announces itself. It shows up as a water bill that has crept up, a floor tile that lifts, or a smell in the stock room that no amount of cleaning shifts. Before you book anyone, fifteen minutes with the water meter and a torch will tell you whether you have a leak and, often, roughly where it is.
1. Find and read the water meter (five minutes)
Most retail units have a meter at the boundary, in a footpath chamber outside the unit, or in a service corridor. Shopping centre units are often fed from a shared riser, so ask the centre management team where your sub-meter is.
- Turn off every tap, urinal, cistern and appliance that uses water. Ice machines, coffee machines and water-fed chillers count.
- Read the meter, including the red digits or the small dial.
- Wait ten minutes without using any water.
- Read it again.
If the reading has moved, water is leaving the pipework between the meter and your outlets. A slow creep on the small dial points to a small leak, such as a weeping joint or a dripping ball valve. A steadily turning dial with everything off usually means a break in a supply pipe, often underground.
2. Check the heating pressure (two minutes)
If the unit has a gas or electric boiler for heating or hot water, look at the pressure gauge on the front. A sealed system should hold its pressure between visits. If someone is topping it up every week, the water is going somewhere: a radiator valve, a buried pipe under the floor, or the boiler itself.
Note the pressure each morning with the system cold. If it keeps falling between cold readings and needs topping up, that points to the heating circuit (or a faulty relief valve or expansion vessel) rather than the mains supply.
3. Walk the four places leaks show first (five minutes)
Take a torch and walk the unit in this order:
- Under and behind the tills. Cold-water pipes to the customer WC and staff kitchen often run under the counter run. Look for lifted vinyl, staining on the plinth and a musty smell.
- The customer and staff toilets. Check for water around the base of the pan, a cistern that keeps refilling, and damp on the wall shared with the shop floor.
- The plant room or boiler cupboard. Look at the pipe insulation for staining and at the floor beneath any pressure-relief pipe.
- The stock room ceiling and party walls. In parades and centres, the leak is often next door or upstairs. A stain that is worse at the top of the wall points upwards; one that is worse at the skirting points to your own floor.
4. Decide what to do
| What you found | What it usually means | Next step |
|---|---|---|
| Meter moves, no visible water | Underground or under-floor supply leak | Call for a non-invasive survey. Do not dig. |
| Boiler pressure drops, no visible water | Heating circuit leak, often under the floor | Call for a heating leak survey with tracer gas or thermal imaging. |
| Visible drip or wet joint | Plumbing fault at a fitting | A WaterSafe plumber can repair it directly. |
| Stain high on a wall or ceiling | Leak from the unit above or the roof | Tell the landlord or centre team the same day and photograph it. |
Why not just start digging?
Because the wet patch is often not over the leak. Water travels along pipe runs, under screeds and along the top of damp-proof membranes, and surfaces wherever there is a gap. Opening up the floor where the stain is means a closed shop, a damaged fit-out and a good chance the pipe is not there. Thermal imaging, acoustic listening and tracer gas find the actual break from above, so any opening is usually small and in the right place.
If the meter test says you have a leak, take a photograph of both readings and the time between them. That number is useful to the engineer and to your insurer.
Frequently asked
The meter is still moving with everything off. Is that definitely a leak?
Almost always, yes. Check that no urinal flush, ice machine, coffee machine or water-fed chiller is drawing water, then repeat the test. If the dial still turns, water is leaving the pipework somewhere between the meter and the taps.
Our unit does not have its own meter. What then?
Ask the landlord or managing agent which meter serves your unit; shared supplies in centres and parades are common. If a test is impossible, a leak engineer can isolate and pressure-test your section instead.