Pipes on a brick wall.

Why Slab Leaks Occur and How To Fix Them

Where on the floor have you seen moisture recently? Are you dissatisfied when the shower’s water pressure is low? Do you have higher-than-average utility bills? That might be indicative of a slab leak in your home. To fully understand a slab leak, you must first understand the plumbing system that is the basis for your home’s structure. Many homeowners fail to realize that in addition to the water supply, there is a sewage system in their homes. The sewage system collects and transports wastewater from all drains to the municipal sewer pipes. Your home’s water-using fixtures and appliances are connected to a network of pipes and fittings that may leak into the walls, floors, or foundation. This blog will discuss why slab leaks occur and how to fix them.

How often do slab leaks occur?

Older homes with copper or galvanized steel pipes corrode fast and are more prone to slab leaks. External pressure acting on the lines, such as an earthquake, an underground stream, or soil erosion, also increases the likelihood of their occurrence.

As you know, leaks can be a severe nuisance.  Because the water can cause damage to your items and belongings, experts from movingtransparent.com advise putting them in a safe storage unit until you fix the leak. If you live in an area where the water is particularly acidic or alkaline, your pipes may corrode more quickly. Abrasion, which can lead to leaks, can also be caused by debris in the water and sewage. As the water in the pipe heats up, it expands and presses against the concrete. By doing that, it causes stress and eventually a leak.

Slab leaks cause

If a water pipe ruptures beneath a concrete slab, the result is a leak known as a slab leak. There may be a severe plumbing issue underneath the surface, and you wouldn’t even know it. Here are the most common reasons why slab leaks occur:

Substandard construction

Most slab leaks result from faulty or poorly installed pipes. Suppose your water pipes got damaged during installation, such as being kinked, dented, or distorted. In that case, the corrosive properties of the water traveling through them might eventually wear down the pipes to the point where they leak or even burst.

Particularly vulnerable to corrosion are copper pipes because of their softness and outside exposure. Especially in older homes, a slab leak may necessitate the installation of new pipes rather than a repair.

Gray pipes.
 Faulty pipe installation is one of the reasons why slab leaks occur.

Changes in soil volume due to growth or shrinkage

One of the most common reasons why lab leaks occur in structures is because of significant soil movement. The earth undergoes expansion and contraction when the moisture content of the ground fluctuates.

As a result of the expansive clay and sandy soil, as well as other ground types prone to vertical and lateral displacement, slab foundations in the USA are especially at risk.

If the ground shifts too much, it might damage the pipes carrying water to the building. Pipe leaks could cause more earth movement, setting off a chain reaction that might not be seen for a while.

 A leaf on the ground of dirt.
Slab leaks are widespread after earthquakes. 

Chemical reactions

Copper is a popular material for water pipes. Eventually, this metal might break down the soil’s mineral content by reacting with the other elements. This process, called electrolysis, is how this happens.

The water temperature in the pipe also plays a role here. While cold water pipes tend to erode from the inside out, hot water pipes tend to rust from the outside. There will always be a slow leak from the pipes into the flooring.

Fixing a slab leak

Fixing a water leak in a concrete slab is a job for experts because of the complexity of the problem. Here are a few ways to fix slab leaks:

Repairing a leak without digging up an entire slab

Slab leaks may usually be fixed with minimal demolition when trenchless plumbing is used. To remedy the slab leak, your contractor must drill a few holes. It is the most cost-effective and least disruptive approach for fixing leaks beneath a building’s slab.

The professional plumber doing the slab repair will use epoxy pipe liners to protect the pipe from further leakage. To gauge the extent of the destruction, they’ll employ a camera. If trenchless repair is possible, the pipe will be cleaned, and an epoxy pipe liner will be installed. After that, the pipe will be inflated, and the epoxy will cure. The entire operation might take only a few hours to complete. If the water lines are severely damaged, pipe splitting, in which new pipes slightly more significant than the old ones are put in, may also be done.


The expense of cutting through your concrete slab and replacing a burst pipe is in the thousands. Slab leaks can be repaired more quickly by installing a new pipe above the damaged floor, either outside the concrete slab or in the attic. One advantage of replacing a pipe rather than repairing a broken one in your foundation is that the replacement pipe may be easily accessed in case of a leak or other problem. The area surrounding your house’s foundation or the attic is where you’ll find the newly placed pipe.

A person holding a yellow pipe.
In some cases, repiping is the best option.

Install a lining in the pipes.

You can patch the leak in your galvanized steel or copper pipes under the house without tearing up the foundation by inserting a thin layer of the epoxy coating into the pipes. Once you inject the epoxy into the pipe, it hardens to cover any cracks or holes.

In conclusion

After learning why slab leaks occur makes it possible to take on them on your own. However, it’s best to get a professional plumber to help you locate the leak and fix it immediately to avoid any of the many potential difficulties.

Further, early leak detection aids in reducing repair and maintenance costs. Therefore, a qualified professional should inspect your home regularly to identify any early signs of a slab leak.