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Reliance Plumbing Sewer & Drainage, Inc. Blog

Is a Slab Leak Really as Bad as It Seems?

cracked-concrete-foundationThe short answer to this is, “yes.”

Sure, you don’t want to deal with any type of leak in your home, but this is a particularly ominous one.

A slab leak is any leak that occurs in the hot or cold water lines that run beneath the concrete foundation of your home. Not only do slab leaks cause significant water waste, but they also can cause damage to your property, leading to mildew and mold growth and adding extra strain on your water heater if the leak is happening in the hot water pipes (which the majority of the time, it is).

Fortunately, you have our professional and highly trained plumbers on your side, equipped with the right tools to locate this type of problem and fix it as unobtrusively as possible—though it does bear mentioning that these slab leaks are pretty obtrusive in their own right, which is why we never downplay their severity. Wondering what causes a slab leak? Read on!

Increased Pressure

The leading cause of slab leaks is an increased amount of pressure being placed on the pipes beneath your home’s foundation. This type of pressure can come from a variety of sources, such as the shifting of soil causing the home’s foundation to shift, or a poor construction job on the home to begin with. This can lead to problems like flooding and the rotting out of any building materials at the ground level.


Remember how we mentioned that most of the time, slab leaks happen with hot water lines? The reason this is the case is because corrosion is more common in these lines. The reaction between the heat of the water and the material surrounding the pipes can cause the pipe to begin corroding from the outside.

Corrosion can absolutely happen with cold water lines too—it just bears mentioning that it’s more common in hot water pipes.

Aging homes are more likely to experience pipe corrosion than newer households. This is because they often have copper or galvanized steel pipes in their foundations. Copper is corrosion-resistant, but it’s not corrosion-proof. A process referred to as electrolysis could still cause copper corrosion.


Is there an area of your home where you see exposed pipes? Perhaps beneath your bathroom sink or in your basement. You may have noticed at some point that the sometimes rattle around a little when water passes through them. This happens because those pipes are expanding and contracting with temperature fluctuations.

Today’s piping materials are built to last, however in an older home, pipes that rattle like this beneath a concrete foundation will start to experience abrasion as they rub against the rock surface. Over time, this will lead to damaged pipes and subsequent leaks.

This is another one of those issues that’s more common in hot water lines, but definitely not one to ignore when it comes to cold water lines. No matter the situation, if you suspect a slab leak in your home, the best thing you can do is call our pros!

For expert plumbing service, installations, or maintenance contact Reliance Plumbing Sewer & Drainage, Inc. Our knowledgeable plumbers serve the North Shore and Northwest Chicago suburbs. Rely on Reliance!

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