The Common Causes of Slab Leaks

A slab leaks is a serious plumbing emergency that occurs under your home’s concrete slab or foundation. Water lines run beneath the concrete slab that transport water in and out of your house. The leak can result from a water pressure build-up or the age of the water lines.

If those conditions exist, a water leak can occur. Another common slab leak caused is a sudden rupture of one of the water pipes leading into or out of your house.

What is Slab Leaks?

Slab Leak, also known as a foundation leak, this kind of leaks can cause a serious problem in your house. A common cause of a slab leak is when the foundation for the home has flowed. While the cement is still wet and setting, copper pipe is laid in to run wherever it needs to go for the plumbing system of your home. This is a fairly common practice.

The problem occurs when the copper piping is soft. As the cement hardens, any kinks, bends, nicks or other imperfections in the pipe are exacerbated.

Over time, these problems can become more and more magnified, eventually resulting in one or more tiny leaks in the pipe. This causes water to leak directly into the concrete foundation.

This causes many problems for homeowners, both short-term and long-term.

In the short term, it reduces water pressure and increases water consumption, resulting in higher monthly bills for poorer water delivery. These are inconveniences and annoyances, but nothing compared to the long-term damage that a slab leak can cause.

The moisture in the foundation becomes a breeding ground for mold. This mold can spread throughout the foundation and the house, which is a serious health risk for you and your family.

Mold and mildew spores negatively impact air quality and can lead to illness. Plus, the moisture weakens the foundation gradually over time. Eventually, you have a less structurally sound home and may succumb to mold, which can cause thousands of dollars to repair.

What Causes Slab Leaks?

Slab leak detection is not always easy. The most obvious sign is a puddle on the basement floor or elsewhere. Here is the list of the most common causes of slab leaks.

The Mysterious Sound of Running Water

A common indicator that there is a water leak hidden beneath the concrete slab of your foundation is the sound of running water when no water is in use. Unless you live by a babbling brook, it is vital that you report any such sounds immediately.

Even if it is not a slab leak, you likely have a leak somewhere in your home. If it is a slab leak, that means that enough water is leaking to be audible through the slab.

Scheduling repairs sooner than later is surely your best course of action in either event.

Warm Spots on the Floor

Your slab leak may be in either a hot or cold water line. A warm stretch may recognize a hot water leak on your foundation floor. Not only will a hot water leak of this nature do real damage to your home, but it can also drive up energy costs and put a lot of strain on your water heater. Needless to say, we recommend immediate action.

Damp Carpeting and Water Stained Walls

If you find a damp area on your carpet – and you’ve not got a little critter being housebroken – then you are wise to have the situation assessed by a professional plumber. This is another common sign of the slab leak. You may also notice wet spots creeping up the base of your walls.

How to deal with a slab leak?

Slab leaks can be repaired, but sometimes after repairing one, another will crop up shortly. However, they still must be repaired immediately before the problem spreads and becomes too big to handle.

There are a few different methods to repair slab leaks, including breaking up the foundation and laying a new pipe or lining the existing pipe with epoxy. Consulting with a professional is the best way to determine which method is right for you.

Mas Broto

Written by: Mas Broto

Mas Broto is a small business owner with 30 years experience in the real estate industry. He is the founder and editor of, the most comprehensive free home improvement website on the planet!