How to Find a Hidden Water Leak in Your Home
The most damaging leaks are the ones you can't see. Here's how to catch a hidden leak early — before it becomes mold or rot.
A hidden leak can run for weeks behind a wall or under a floor, quietly feeding mold and weakening structure. Catching it early is the difference between a small repair and a major restoration.
Warning signs of a hidden leak
• An unexplained jump in your water bill with no change in usage.
• A musty smell in a particular room or closet.
• Stains or discolouration on walls, ceilings, or baseboards.
• Peeling paint, bubbling, or warped flooring.
• The sound of running water when nothing is on.
• Warm spots on the floor, which can indicate a hot-water line leak.
The water-meter test
This simple test confirms whether you have a leak anywhere in the system:
• Turn off every water fixture and appliance in the house.
• Find your water meter and note the reading.
• Wait one to two hours without using any water.
• Check the meter again. If it moved, water is escaping somewhere — you have a leak.
Common places hidden leaks start
• Under sinks and behind toilets — check for dampness and corrosion.
• Around the water heater and its connections.
• Behind the dishwasher, washing machine, and fridge water lines.
• Inside walls where pipes run — often only visible as a stain.
• The foundation and basement, where groundwater can mimic a plumbing leak.
When to call a professional
If the meter test confirms a leak but you can't find the source, or if you see staining and smell mold, it's time for help. We use moisture meters and thermal tools to locate hidden water and assess the damage, then handle the restoration — including any mold remediation the leak has already caused.
Don't wait it out
Hidden leaks never get cheaper. Mold can take hold within 24 to 48 hours of materials staying wet, so the faster a leak is found and dried, the less you lose. If you suspect water where it shouldn't be, our 24/7 team can help you track it down.