Master Plumber in Atlanta Georgia

How to Fix Leaking Pipes Under A Slab Foundation

There is no pipe, water, or sewer line that lasts forever. Erosion and leaks are a common occurrence and are caused by wear and tear and decay. Most homes see this happening sooner or later.

Most people get scared when they think about leaks beneath a slab foundation. The repair job that comes with it sounds difficult and expensive. In reality, it may be much easier to fix the leaking pipes under the slab.

The biggest challenge is locating the pipe and getting direct access to the problematic area. Once you know about the leak’s location, the fix is just a cut away.

In the following post, we’ll together with go over the main points you should know about fixing the leaking pipes under a slab foundation.

Why do slab leaks happen?

First, let’s look at why slab leaks happen in the first place.


Hot water pipes pose an especially high risk of abrasion. Heat causes them to expand, raising the risk of rubbing against the surrounding materials, such as concrete and gravel. As the friction becomes a constant part of the expansion process, it’s only a matter of time when leaks start to happen.

Excess pressure

Soil shift and erosion can put too much pressure on the pipes. The flooding could be extensive when the leak results from outside pressure.

Old homes

Just living in an older home raises the risk of facing slab leaks. Often enough, older houses come with pipes made from galvanized steel or copper. These materials give way to corrosion more easily. And since the house has been there for a long time, the extended period of being subject to different forces ups the potential for any leaks.

Poor construction

This is a very typical reason for slab leaks. Usually, the trouble is in the pipes’ poor quality or just bad workmanship. Flowing water carries abrasive potential, which means that improperly installed pipes can start to leak faster. Bent, torn, and dented pipes along with constant water flow invite trouble.

Water properties

Is the water too acidic or alkaline? In both cases, the pipe corrosion may happen quicker compared to more neutral water. Check this regularly if there’s any concern. The pH level of your water has to be somewhere between the values of 6.5 and 8.5. More or less than that means potential issues with the pipes.

How can I be sure it’s a slab leak?

Many signs point to a potential slab leak. Do you hear the sound of gushing water under the floor? That might indicate a leaking pipe under the foundation. Also, noticing damp areas or actual water on your floor is a real giveaway.

When the hot water line leaks, you may feel strangely warm spots on the floor while walking barefoot. Mildew and mold on the carpet serve as important red flags too. And the numbers on your water bill could definitely reflect the constant leaking!

But when it’s a sewer line, things are usually different. Typically, sewer line leaks can go undetected for a much longer time. Actual foundation damage might be one of the first signs. Definitely explore the possibility of a sewer line leak when you discover foundation heaving or just a raised part of the floor.

What are the steps for fixing the pipes?

1. Look for the leaking spot.

It’s not always so simple. Most likely, you’ll need the help of a plumber. They use special devices that allow them to locate the right spot. The water must be turned off for this. Then your plumber will pump the air into the lines to get any remaining water out of the way. Now, the plumber listens for any air escaping the pipes under the slab.

2. Plan for repairs

After making sure the location of the leak, it’s time to make a plan. How will you exactly repair this problem? In many cases, replumbing the whole house makes more sense than repairing any worn-out pipes. This is especially true when the old plumbing uses galvanized metal. Making patchy repairs sets you up for reoccurring trouble in the future.

3. Access the leak

The next step calls for access to the leaking pipe. The floor will have to be removed in order to expose the concrete slab. Then a hole has to be made into the slab using a jackhammer.

You are best off protecting your furniture by covering them or even moving them away from the work site. After making the hole, it’s important to remove any dirt to see the pipes more clearly.

4. Repair the pipe

Usually, this means cutting the damaged section, removing it, and soldering a new piece into its rightful spot. When opening up the foundation proves to be a very difficult or uneconomical solution, pipe coating is another option. This is done using an epoxy coating to fix the pipe without cutting any part of the slab.

So, what do I need to know about pipe repair under a slab?

The first step is to notice the signs of a slab leak. Water bills that don’t make sense, damp or wet areas on the floor, and the sound of water gushing under the floor. All of these are worrying signs of a leak.

Additionally, you should be aware of the typical risk factors. Poor construction techniques and materials, shifting soils, too acidic or alkaline water, and living in an old home raise the risk of experiencing slab leaks.

Fixing the pipes means you have to find the approximate spot for the leak. Special listening devices come handy. Use a jackhammer to open up the concrete slab. After removing the dirt, it’s time to fix the pipe.

There are times when replumbing the whole house is the best option. Usually, it’s the case when the piping is old and would spring new leaks soon enough anyway.