Why leaks hide in commercial spaces
Many Fullerton commercial buildings are slab-on-grade, with water and drain lines running under the concrete. Kitchens add more hidden pipe behind cook lines, under bars and inside walls behind walk-in coolers. Floors are wet from mopping anyway, so a small leak can go unnoticed for months.
Hidden leaks show up in other ways: a water bill that climbs without explanation, a warm spot on the floor from a hot-water line, flooring that lifts, or a wall that stays damp. Walk-in coolers are a special case because condensate lines and door heaters add moisture that can look like a plumbing leak.
Signs of a hidden leak
A simple meter test you can do
- Close everything.After hours, make sure no fixture, ice machine, dish machine or irrigation is running.
- Read the meter.Note the reading and watch the leak indicator, if the meter has one.
- Wait.Check again after a period with no water use.
- Interpret.If the reading changed, water is going somewhere. Share the readings with your plumber.
How plumbers locate leaks
| Method | What it does |
|---|---|
| Isolation testing | Closing valves on sections of piping to narrow down which branch is losing water. |
| Acoustic listening | Electronic equipment picks up the sound of water escaping under a floor or in a wall. |
| Thermal imaging | Shows temperature differences, useful for hot-water leaks under slabs. |
| Pressure testing | Checks whether a line holds pressure after it is isolated. |
| Camera inspection | Used on drain lines to find cracks and failed joints that leak wastewater. |
Repair approaches for a slab leak
Spot repair through the floor
- Cut the slab at the leak and fix the section.
- Makes sense when the rest of the line is in good shape.
- Kitchen equipment may need to be moved and the floor restored.
Reroute the line
- Abandon the line under the slab and run new pipe through walls or ceilings.
- Can be better when the old line has several leaks.
- Avoids repeated floor cutting but changes where pipe is visible.
Questions to ask about leak detection
- Which methods will you use, and how confident are you in the location?
- Is the leak on a supply line or a drain line?
- Should we repair this spot or reroute the line?
- What equipment needs to move, and how long will the area be out of use?
- Will you document what you found for our landlord or insurer?
Common questions
How do I know if the leak is under the slab?
Warm floor spots, a meter that moves with everything off and damp flooring away from any fixture all point that way. A plumber can confirm with isolation testing and listening equipment.
Is water around a walk-in cooler always a plumbing leak?
Not always. Condensate drains, door gaskets and defrost cycles can cause water too. A refrigeration technician and a plumber may both need to look.
Does fixing a slab leak require a permit?
It depends on the scope. Rerouting or replacing piping often does. Check with the city and ask your contractor.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.