Leak Detection & Slab Leaks in Newark, CA

A lot of Newark was built slab-on-grade in the 1960s and 1970s, which means the home sits directly on a concrete slab and the water lines run inside or beneath that slab instead of through a crawlspace. When a supply line under the slab springs a leak, you cannot just look under the house and see it. The water is trapped below the concrete, and the first clue is usually indirect: a water bill that climbs for no reason, a warm spot on the floor over a hot line, or the faint sound of water running when every fixture is off.

After fifty or sixty years, the original copper under those slabs is at the age where pinhole leaks start showing up. Newark's water from the Alameda County Water District is moderately hard, and over decades that mineral content works on copper from the inside, which is one of the reasons a single pinhole can turn into several across the same run. We see this pattern across the older slab homes in Old Town Newark and Lakeshore in particular.

The whole point of leak detection is to pinpoint the problem so we are not jackhammering the floor to go looking for it. We start with electronic detection: acoustic listening equipment that hears water escaping under the slab, plus correlation tools that narrow the location down to a small area rather than a whole room.

When the question is whether a hidden line is leaking at all, pressure testing answers it. We isolate the supply system, put it under pressure, and watch whether it holds. A line that bleeds off pressure with no fixture open is leaking somewhere, and that tells us to keep tracing. By the time we recommend touching concrete, we know where the leak is and roughly how big the job is. No guessing, no exploratory demolition.

Once we have located a slab leak, there are two real ways to fix it, and we will tell you straight which one fits your situation. A spot repair opens the slab at the one failure point, repairs that section, and patches the concrete back. It is the smaller, less costly job, and it is the right move when the rest of the line is still in good shape and you have a single, isolated leak.

Rerouting abandons the failing under-slab line and runs a fresh line overhead or through the walls instead, bypassing the slab entirely. We recommend it when the existing pipe has already leaked more than once, when the copper is clearly at the end of its life, or when the leak sits somewhere that would be brutal to reach through the slab. Rerouting costs more up front, but if your copper is failing in multiple places, chasing one pinhole at a time under the concrete usually costs more in the long run. We would rather have that conversation honestly than sell you a patch that fails again next year.

A slab leak left alone does not just waste water. It can saturate the slab, lift or crack flooring, and feed mold under the home, so finding it early genuinely saves money on the repair that follows. If you have noticed an unexplained drop in water pressure alongside any of the warning signs, that is worth a call before it gets worse.

Because Newark's hard water is part of what wears these lines out, we will also talk through whether a softener makes sense for your home, since easing the mineral load takes some of the strain off copper going forward. And when a repair or repipe rises to the level of work the City of Newark requires a permit for, we pull the permit and schedule the inspection so the job is done to code and on the record, which matters when you sell the house.

We are based right here in Newark, 94560, not dispatched in from across the Bay, so we already know the slab-on-grade housing stock, the age of the copper under it, and the City's permit process. That means we show up understanding what we are likely walking into, and we get to you faster when a leak turns into an emergency. Every job comes with a clear diagnosis, the location of the leak shown to you, and your spot-repair versus reroute options explained in plain language before we start. That is how Quality Plumbing has worked since 1994, and it is how we still work today.