The problem: water you can hear but not see
Water under pressure makes noise when it escapes through a small opening. A pinhole in a supply line, or a failing joint, can produce a hiss or a steady trickle, and in a quiet room that sound carries through the floor and walls. Because the line is buried in or under the slab, nothing is visible, which is what makes the sound so puzzling.
The sound is often noticed late at night or early in the morning, when the household is quiet and the air conditioning is cycling off. People describe it as a hiss, a gurgle, a faint rushing or the sound of a tap left slightly open. Some can pinpoint a room. Others only know that it seems to come from the floor.
What else may go with it
The sound may be the first sign, or it may sit alongside others: a water meter that moves with everything off, a bill that has risen, a warm patch on the tile or damp along a baseboard. In some homes it comes and goes, which can make it easy to dismiss.
Pay attention to when you hear it. A sound that is constant, regardless of the time of day or what else is running, points toward a leak under constant pressure. A sound that appears only after a toilet flush or after an appliance has run is more likely to be something in the plumbing that is working as designed.
Describe the sound and we will ask a few questions.
Speak With Someone LocalWhat else produces the sound
Not every noise in a pipe is a leak. A toilet whose fill valve has not fully shut will hiss while it tops up the tank. A water softener or a treatment system can cycle on its own. An ice maker refills. A water heater can tick and rumble as it heats. Pipes expand and contract with temperature and can knock or creak. An irrigation timer may start a zone before dawn.
Pool equipment, an auto-fill or a nearby neighbor's plumbing in a condo building can carry sound as well. Going through these takes a few minutes and often explains the sound. If it still persists after you have checked them, a meter check is the next step.
Check toilets first. Lift each tank lid or listen close to the fill valve. A hiss that stops after a moment is normal. One that continues is a toilet issue, not a slab leak.
Look at timers and appliances. Irrigation controllers, the ice maker, a softener and the dishwasher can all draw water when no one is nearby.
Note where it is loudest. Walk slowly and write down the room and whether the sound is louder near a wall, a floor or a fixture.
Do the meter check. With everything off, watch the leak indicator. Movement means water is going somewhere on the property.
Why Florida slab homes carry the sound
Concrete conducts sound well, and a slab can carry the noise of a leak some distance from its source. In a house with tile throughout, there is little to muffle it. Many Florida homes also have water lines that run through the slab beneath the rooms they serve, so a leak is physically close to the floor you stand on.
Sandy soil and a high water table in many areas mean escaping water drains away, so the sound may be the only sign for a long time. A leak that is quiet in the daytime can seem loud at night. See why Florida leaks hide for the longer explanation.
A person answers, day or night.
Call Now: (855) 731-0997What to do and what not to do
Do the meter check and write down what you hear and where. If water is surfacing, turn off the main shutoff if you can reach it safely, keep clear and move valuables. If the sound is loud and the meter is moving fast, closing the main and calling is sensible.
Please do not press your ear to a wall with water nearby, do not cut into drywall or break the floor to find the source and do not touch electrical items near damp areas. If you smell gas, leave the building and call the gas utility and emergency services from outside. The technician has equipment made for this job.
How a technician listens
The technician starts by isolating the water system, closing off sections so that only one line is under pressure at a time. Sensitive acoustic microphones are then moved across the floor in a pattern, and the sound of escaping water is loudest closest to the break. The technician filters out other noise and checks the reading at different points.
Pressure testing confirms whether the line holds, and thermal imaging helps on hot lines. The position is marked and cross-checked before anyone discusses repair. See how slab leaks are found and slab leak detection.
Timing depends on location and is confirmed on the call.
Get a Leak Crew Out TodayIf it is a slab leak
The technician explains the options for that line: a spot repair through the slab, a reroute above the slab, lining where suitable, or wider repiping if several lines are involved. A line that is making noise may be one that has been leaking for some time, so the technician may also describe what they see on nearby pipe.
Upfront pricing and no hidden fees apply before work begins, and the decision is yours. See slab leak repair for how each option works.
Afterwards
After a repair, the lines are tested to confirm that pressure holds, and the sound should be gone. If you still hear something, tell the technician, since it may be a second source.
Restoration companies handle drying and cleanup of any wet flooring. If the noise returns later, or comes from a different part of the house, read about repeat slab leaks.
Describing where you hear it
Walk through the house with everything off and note where the sound is loudest. Is it in a wall, near the heater, by the front of the house or in the middle of the floor? Does it come and go? A short description helps the technician start in the right place.
Avoid putting your ear to a wall that has outlets. Stand back and listen from a safe distance.
Listening in the quiet hours
Early morning and late evening are the best times, when the street and the neighbors are quiet. Switch off fans and the air handler for a minute if you can do so safely. A faint hiss that you did not notice in the day can stand out.
If you hear it and the meter is also moving, call.