Slab Leak Detection & Repair in Pomona, CA
Most pipe leaks are easy to spot. Water shows up on the floor, in the ceiling, or under a sink. A slab leak is different. The pipe is buried under your concrete foundation, so by the time you notice anything, it’s often been leaking for weeks.
We’ve pulled up more than one Pomona driveway to find a pinhole leak in a copper line that had been dripping onto the same spot of soil for a month, slowly working its way through a crack in the slab. It’s rarely dramatic. It’s just quiet and expensive if it sits too long.
Signs You Might Have a Slab Leak
- Your water bill jumped and nothing changed. This is usually the first clue. A leak that runs 24/7 under your house adds up fast, even if it’s small.
- A warm spot on the floor. If the leak is on your hot water line, the slab above it can actually feel warm to the touch, sometimes even through carpet or tile.
- You can hear water running when every faucet is off. Turn everything off in the house, go somewhere quiet, and listen. A hissing or trickling sound near the floor is a real sign.
- Damp carpet or flooring with no obvious source. If a section of flooring stays damp and there’s no spill, no nearby plumbing fixture, and no rain gutter issue outside, the water may be coming from below.
- Cracks in the slab or nearby walls. Water pressure building up under a foundation can eventually push up through a crack or cause new cracking in drywall above it.
- Mold or musty smell with no visible water. If something smells damp but you can’t find a leak anywhere above the floor, it’s worth checking below it.
How We Actually Find the Leak
We don’t guess and we don’t tear up your whole driveway hoping to get lucky. The first step is always acoustic leak detection — a sensitive listening device that picks up the sound of water escaping under pressure through a tiny crack or hole. Water moving through a small gap makes a specific sound, and with the right equipment, we can narrow down the leak to a fairly small area before anyone touches a shovel or a saw.
Once we’ve marked the spot, we open a small section of concrete right there, not the whole slab. Most slab leak jobs involve a hole a few feet across, not a full excavation.
What Causes Slab Leaks in Pomona
A few things show up again and again in this area:
- Old copper pipe. A lot of Pomona homes still have the original copper supply lines run under the slab when the house was built. Copper doesn’t last forever, especially with the area’s harder water slowly wearing at it from the inside.
- Ground movement. The San Gabriel Valley sees real, if generally minor, seismic activity, and normal soil shifting over decades can put slow pressure on a rigid pipe until it finally gives.
- Abrasion. Sometimes a pipe was laid too close to a rock or a rough patch of soil when the house was built. Every time water pressure makes the line move even slightly, it rubs against that same spot for years until it wears through.
- A poor original installation. Sharp gravel backfill or a pipe that wasn’t properly wrapped can cause slow damage that doesn’t show up for decades.
Repair Options
Spot Repair
If the leak is isolated to one small section, we can access just that spot, cut out the damaged piece, and replace it. This is usually the fastest and least expensive option when it’s available.
Reroute
Sometimes it’s actually simpler and more reliable to leave the damaged pipe under the slab alone and run a new line through the attic or along a wall instead. This avoids repeatedly disturbing the foundation and can be a smart move if the existing under-slab line is old enough that more leaks are likely.
Full Repipe
If your home still has its original copper or galvanized lines and you’re dealing with more than one leak, it may be time to talk about repiping the whole house rather than patching each new leak as it shows up.
| Job Type | Typical Cost |
|---|---|
| Leak detection only | $150 – $400 |
| Spot repair (small concrete access) | $1,000 – $3,500 |
| Reroute (avoiding the slab entirely) | $1,500 – $4,000 |
| Full repipe | $4,000 – $15,000+ |
The real number depends on how long the leak ran before it was caught, how deep the pipe sits, and whether the water reached your flooring or drywall. A free inspection with acoustic detection is the only way to get an exact figure for your home. For a broader breakdown of burst pipe repair pricing in general, see our full cost guide.
Will Insurance Cover a Slab Leak?
Usually, the sudden water damage the leak caused (warped flooring, damaged drywall) is covered if the leak was recent and sudden. The cost of finding and fixing the pipe itself is sometimes covered under a “hidden water damage” or “tear-out” provision, but not always; it depends on your specific policy. Worth a call to your insurer with the leak detection report in hand. For the full picture on what California policies typically cover, see our insurance claims guide.
Frequently Asked Questions
How do I know if it’s a slab leak and not just a regular pipe leak?
A regular leak usually shows up fast, near a visible fixture like a sink or a water heater. A slab leak shows up slowly, through a rising water bill, a warm spot on the floor, or a sound of running water with no visible source. If you can’t find where the water is coming from above the floor, it’s worth checking below it.
Do you have to break my whole driveway or floor to fix it?
No. Acoustic leak detection lets us find the leak within a fairly small area first, so we only open the section of concrete that’s actually necessary, usually just a few feet.
How long does a slab leak repair take?
Detection and a spot repair can often be done in a single day. A reroute might take one to two days depending on the distance. A full repipe is a bigger job, often several days.
Can a slab leak cause foundation damage if I wait?
Yes, over time. Water sitting under a foundation for months can erode soil and, in rare cases, contribute to settling or cracking. It’s not usually an emergency-today situation, but it’s not something to put off for months either.
What’s the first thing I should do if I suspect a slab leak?
Check your water meter with everything in the house turned off. If the dial is still moving, you have a leak somewhere. From there, call for acoustic leak detection rather than guessing at the location yourself.
Call Now: (840) 226-2371