Slab Leak Detection & Repair in San Jose, CA
Almaden, Blossom Valley, Cambrian and Santa Teresa are full of houses built slab-on-grade between roughly the mid-fifties and the mid-eighties, with the copper supply lines buried in the concrete. That was a sensible way to build. It becomes a problem fifty years later, when one of those lines finally fails and there is a slab sitting on top of it.
What catches people off guard is that a slab leak almost never shows up as water. You get a patch of floor that is warm underfoot, a water bill that has climbed for no reason you can name, a water heater running more than it used to, or a faint hiss late at night with everything in the house shut off. Any of those can be explained away for months, and usually is.
What happens next is better than most people fear. We pressure-test the system and isolate the hot and cold sides to work out which one is losing, then pinpoint the spot acoustically before anybody touches concrete. Nine times out of ten we do not break the slab at all. Abandoning the failed run and rerouting a new line overhead through the attic or the walls is faster and cheaper, and it keeps a jackhammer out of your living room. When the slab genuinely is the only route, we say so and explain why.
When people call us about this
- A warm patch on the floor that is still warm at night
- Water bill climbing over consecutive months with no change in use
- The meter still turning with every fixture in the house shut off
- A faint continuous hiss with the house quiet
- New cracks in flooring, or a floor that has started to lift
Questions we get asked
How can I check for a slab leak myself?+
There is a simple test and it takes about twenty minutes of patience. Shut off every fixture and appliance in the house that uses water, including ice makers and irrigation. Go out to the meter, note the reading, and leave it a couple of hours with nobody flushing or washing anything. If the meter has moved, water is going somewhere it should not be. That does not prove the leak is under the slab, but it proves you have one, and it is the single most useful piece of information you can give us over the phone before we arrive.
Do you have to break up my floor?+
Usually not. Our default is a reroute: we abandon the failed section in the slab, leave it where it is, and run a new line overhead through the attic or inside the walls to reconnect the fixture. That is generally faster and cheaper than breaking concrete, and it avoids the dust, the noise and the flooring repair that comes with opening a slab. Where a reroute is not practical (an awkward layout, a single-story house with no attic access, or multiple failures), opening the slab is the right answer and we will explain exactly why before starting.
If one line has failed, will the rest go too?+
Everything under that slab is the same age, the same material, and has spent the same fifty years in the same conditions, so one failure does raise the odds on the next. That said, a single leak in an otherwise sound system is a repair and should be treated as one. We are not going to tell you to repipe on the strength of one pinhole. What changes the picture is a pattern. A second or third under-slab failure within a couple of years is the system telling you something, and at that point a whole-house reroute usually costs less than the repairs will.
Further reading: How to Spot a Slab Leak Before It Wrecks Your Floor and 5 Signs of a Hidden Water Leak in Your San Jose Home.
Describe it to us and we will tell you what it is.
Phone consultations do not cost anything. If it turns out to be something you can sort out yourself, we will say so.
Related work
Slab Leak Detection & Repair across the South Bay
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