Plumbing & Leak Detection in Orange County "The Bitterness of Poor Quality Remains Long After the Sweetness of Low Price is Forgotten"
We Give A Hoot! 949.536.7471

Everything You Need to Know About Slab Leaks

According to the National Association of Home Builders, nearly 96% of homes built in California rest on concrete slab foundations. You may be asking, "what causes slab leaks?" These sort of leaks can come from improper construction, outside pressure, poor water quality, abrasions and even time. We'll explain in further detail below, what those common occurrences are for slab leaks.

Slab foundations are responsible for bearing the entire weight of your home, keeping groundwater out, and acting as a barrier for all potential vapors that could seep into your home. For all of these reasons, you’ll want to make sure that you are keeping your foundation as solid and stable as possible. Keep reading to learn more about:

  • What causes them?
  • what are slab leaks?
  • what signs do I look for?
  • what do I do if I find one?

What is a slab leak?

A slab leak is a term that is used to describe a leak that has developed in the water lines running beneath the foundation of your home. There are two types of slab leaks: a pressure side leak and a drainage side leak. Pressure side leaks are much easier to detect and therefore don’t usually cause a lot of damage; however, because drainage side leaks can go undetected for long periods of time, they can be incredibly destructive to your property.

What causes a slab leak?

Poor Construction

If your home's pipes were installed incorrectly when the house was built, you’ve essentially been set up for a slab leak. Often, construction materials get banged up before or after they're installed in a home. When it's your pipes that are dented or installed incorrectly, you could end up with severe damage down the road.

Water Chemistry

The chemical composition of your water can cause significant pipe corrosion. Your pipes could be in danger of premature corrosion if your water is too acidic, otherwise known as “hard” water, or too alkaline, otherwise known as “soft” water.

For reference, your water should be at a neutral level, between a 6.5 and an 8.5 on the pH scale. You can easily check this with pH indicator strips or by calling your local plumber!


Another reason for a slab leak is abrasion. This is when pipes will rub up against the concrete, gravel, any other rough material or even nearby pipes. This constant friction can cause the pipes to wear down over time and eventually spring a leak. Your hot water pipe is at higher risk of abrasion, this is due to hot water pipes expanding and rubbing nearby pipes or concrete as well.

Outside Pressure

Water pressure isn't the only pressure that can cause a slab leak to appear. If your dirt is shifting underneath your home's foundation, it could cause your home to move and put some slight pressure on the pipes. This shift in the soil can be due to a recent earthquake, soil erosion or even underground streams.


In California, we are no strangers to earthquakes which, if strong enough, can cause the ground around your home—and sometimes even your foundation itself--to shift. Even common soil erosion can have the same effect. When this happens, pressure spikes around your pipes could eventually cause them to burst.

Additionally, if your pipes were built with little room for expansion when they were placed within concrete, gravel or other pipes, the grinding of materials could cause your pipes to wear down and eventually burst.

What are the signs of a slab leak?

There are quite a few signs that could alert you to the possibility of a slab leak. A few of them include:

  • Sudden spikes in your water bill
  • The constant sound of running water, even when your pipes aren’t in use
  • Moisture under carpeting
  • Standing water in your lawn or around the perimeter of your home
  • Low water pressure

If you notice any of these signs, you could potentially have a slab leak or another plumbing issue. It’s time to call your plumber right away.

What to do when you have a slab leak?

If you suspect that you have a slab leak beneath your home, don’t wait. Call a professional plumber immediately! Don’t let a small leak become a large problem; address the issue right away.

At Sage Plumbers, we’ll help you diagnose the problem; determine its source, and provide a solution. Fortunately for California homeowners, slab leak detection has come a long way. We now have multiple different methods for diagnosing and repairing slab leaks that are far less invasive and destructive to your foundation.

Call Sage Plumbers today or visit our website to learn more about slab leaks and our plumbing services!