What Is a Slab Leak?

Water pipes run throughout and under your home. A slab leak is when water escapes from these pipes. It can cause extensive damage to flooring, sheetrock, and paint not to mention your foundation. Water running under the house erodes soil, removing the support needed to keep the slab stable, eventually causing cracks and allowing water to enter your home. Ultimately, structural integrity can be compromised, making your house unsafe to live in.

What Causes Slab Leaks?

Concrete slabs became popular during the construction boom following World War II. It was a faster, less expensive way to build homes using a 4- to 6-inch-thick concrete slab reinforced with metal rebar. Since plumbing lines are run underneath the slab, they are hard to reach, so a cracked pipe or leaky joint can be difficult to repair.

The most common causes of a slab leak include:

  • Shifting Soil: Expansive soils are a leading cause of damage to under-the-slab plumbing, and cause more financial losses than natural disasters such as earthquakes, tornadoes, and hurricanes. Minerals in the soil absorb water, causing expansion that causes pipes and connections to bend and weaken. Once a slow leak begins, it triggers even more soil expansion; pressure on the slab is further increased by hydraulic pressure from the leak.
  • Old Pipes: Damage due to corrosion and abrasion takes time. That’s why plumbing problems are more common in older homes fit with copper pipes. Being softer than other materials, copper is more susceptible to damage over time.
  • Pipe Material: Cast iron pipe, installed prior to the 1960s, can be corroded by water and soil minerals. Galvanized steel from the 1950s is also prone to corrosion, as well as clogging. Plastic pipes, such as ABS, PVC, CPVC, or PEX, tend to be more resistant to corrosion.
  • Abrasion: Changes in water temperature cause pipes to expand and contract. As a result, they rub against rocks or the concrete slab itself. Small abrasions can escalate into leaks. Seasonal fluctuations and going from rainy periods to droughts cause pipes to expand and contract as well.
  • Water Quality: If your water supply is too acidic or too alkaline, pipes can start to corrode and eventually leak under the slab. Ideally, your water should have a pH of between 6.5 and 8.5.
  • Issues with Installation: Sometimes, copper piping is bent too much during installation. If a pipe is hit by a shovel or other excavation or backfilling equipment, or when the concrete for the slab is poured, slab leaks can occur soon or some time after construction.

How Do I Know I Have a Slab Leak?

By the time a slab leak is discovered, it may have been building up for years. The processes by which it occurs can escalate slowly. Some of the most common signs include higher water bills despite no increase in usage. You may hear running water when the taps are off or notice damp or discolored carpets, tile, and other floor coverings. The floor may even be warm or damp in spots.

Other signs of trouble include odors from floors and walls. A visible crack in the foundation means its time to call a professional. However, some signs can be found outside your home. For example, if your lawn or plants near the foundation are growing unevenly, or soil around your house has visibly shifted, then a slab leak can be suspected.

How a Slab Leak Is Fixed?

The problem might warrant repairs or a replacement depending on the age, condition, and materials used in your plumbing system. Some plumbers have their own preferred method. One way to fix the problem is to dig a tunnel under your home to reach the leak. Large sections of damaged plumbing can be repaired this way. It requires a lot of work and sometimes concrete needs to be chipped away if it encases the pipe.

The most expensive and disrupted strategy is to break through the slab, although this may provide the shortest distance by going straight through it. This process is quite messy and you must vacate your home until the contractor is finished. A faster, less invasive method is to re-route the water line through the attic, abandoning the old copper line and avoiding future leaks below the slab.

A pass-through repair involves placing a new line through the old pipe, which then serves as a sleeve. This eliminates the leaking line but reduces its diameter, possibly violating plumbing codes. Pipelining with an epoxy coating can seal leaks and holes. However, upfront costs and uncertainty regarding longevity make this a questionable process.

Contact Fetch-A-Tech for Slab Leak Repair

Our technicians are trained and experienced in slab leak detection and repair. One leak may waste thousands of gallons of water per day. We use the latest technologies to quickly identify the source of a leak, whether it’s inside or outside your home, and prevent any further damage with fast and effective repairs. To get started, schedule service online or call 702-766-3683 today!

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