Slab Leak Repair

A mysteriously climbing water bill. Damp carpet with no clear source. A faint hissing sound beneath your feet. You might be dealing with a slab leak. 

Slab foundations are incredibly common, found in over 70% of new homes in 2024. While they boast some big advantages, like lower construction costs and faster build times, they also present a unique challenge. When pipes beneath the concrete develop leaks, they’re not easy to find or fix. Slab leaks can lead to serious water damage, structural issues, and high repair costs. 

This article goes over your options for repairing a slab leak—and the warning signs you should look for. 

Key Takeaways

• Slab leaks happen when the water pipes beneath your home’s concrete foundation crack or break. 
• The most common causes of slab leaks are shifting soil, corrosion, poor installation, or high water pressure wearing down pipes over time. 
• Warning signs of a slab leak include unexpected water bill increases, damp flooring, warm spots on the floor, low water pressure, and the sound of running water when no fixtures are being used. 
• Common slab leak repair methods include under-slab tunneling, trenchless repair, pipe re-routing, and breaking through the concrete. 
• Investing in professional repair services is the best way to make sure your slab leak repair is done safely and correctly.  

What Causes Slab Leaks?

Slab leaks don’t just happen overnight. They’re usually the result of one or more underlying issues that develop over time. The most common culprits: 

• Shifting soil: Changes in the ground beneath your foundation, from settling to erosion or even earthquakes, can put pressure on pipes, causing them to crack or break. 
• Corrosion: Older copper pipes are especially vulnerable to corrosion from minerals in your water. 
• Poor installation: If your pipes weren’t properly installed when your house was built, they’re more likely to fail down the road.  
• High water pressure: Excessive pressure can wear down pipe joints and connections over time, eventually leading to leaks. 

Signs You Might Have a Slab Leak

Catching a slab leak early can save you from major water damage and high repair bills, but these leaks happen out of sight, so it’s not always easy. Look for these telltale signs: 

• Your water bill jumps unexpectedly: If you’re not taking hour-long showers but your bill spikes anyway, water could be leaking underground. 
• Damp or warm spots on your floor: Moisture seeping up through the foundation or hot water from a leaking pipe creates these patches on your carpet or tile. 
• You hear running water: The faint sound of flowing water could mean a pipe beneath your slab is leaking. 
• A drop in water pressure: If your water pressure is suddenly lacking, it could mean water’s escaping before it reaches your faucets. 
•  Cracks in walls or floor: As water weakens your foundation, structural damage can follow. 

If you notice any of these signs, it's time to investigate. The sooner you fix a slab leak, the less damage you’ll face. 

How to Repair a Slab Leak: 4 Options

A professional slab leak repair team will use one of four methods to fix the problem, depending on the leak location, the condition of your pipes, and your budget.  

1. Under-Slab Tunneling

Under-slab tunneling involves digging a tunnel beneath your foundation to get to the leaking pipe without breaking through the floor. A professional crew will excavate from the outside of your home to reach the damaged section. 

The good thing about this option is, it preserves your floor. This can be a major advantage if you have expensive tile, hardwood, or marble that you don’t want to tear up. However, under-slab tunneling is one of the more labor-intensive and costly methods of slab leak repair.  

Accessibility can also be a challenge. If the leak’s located deep under the center of your home, tunneling might not be feasible.  

When it makes sense: When the leak is near the perimeter of your home, and you want to keep your floors intact.  

2. Trenchless Slab Leak Repair 

Trenchless repair uses epoxy pipe lining to fix leaks without a major excavation. A technician will insert a flexible liner, coated with epoxy resin, into the damaged pipe. The resin hardens to create a new, watertight pipe within the old one. 

The advantage of this type of repair is that you won’t have to jackhammer through your floors. It’s minimally disruptive and, in many cases, can be completed in a single day. The downside is that trenchless repair doesn’t work for all types of pipes. If your pipes are severely corroded or have lots of damage, you may not be able to use this method. 

When it makes sense: Ideal for localized leaks in accessible copper or PVC pipes. 

3. Re-Routing Pipes

Re-routing your pipes involves abandoning the leaking pipe beneath your slab and installing new plumbing through your walls, ceiling, or attic. Your repair team will cap off the old pipe and run a fresh line, completely bypassing the leak. 

The repair team won’t need to dig under your foundation, so you’re less likely to face leaks in the same area. Re-routing is also one of the fastest and most affordable repair options. The tradeoff is that the new pipes may be visible in certain parts of your home, and the repair crew will need to cut into your walls or access your attic or crawl space to install the new pipes. 

When it makes sense: Re-routing is a good choice if you have multiple slab leaks, aging pipes throughout your home, or when other repair options aren’t feasible.  

4. Breaking the Slab

As the name suggests, this slab leak repair means cutting through your concrete foundation to repair or replace the damaged pipe. Once your repair team fixes the leak, they’ll patch the concrete in your slab and restore your flooring. 

Breaking your slab is the most direct repair option, making it effective for isolated, easy-to-locate leaks. The downside, as you can probably imagine, is you’ll need to deal with loud, dusty, and disruptive jackhammering in your home or driveway. 

When it makes sense: Use this option when your leak is easy to find and  access, or if you’re already planning to redo your flooring and don’t mind the disruption. 

DIY vs. Hiring a Slab Leak Repair Professional

Even if you consider yourself handy, slab leak repair isn’t a job for YouTube tutorials or weekend warriors. Finding a leak beneath concrete requires specialized equipment like acoustic listening devices and infrared cameras. The repair itself often involves breaking through foundations and working with pressurized plumbing systems, all while maintaining your home’s structural integrity.  

If you attempt a DIY repair, you could further damage your foundation, cause more flooding, void your warranties, or violate your local building codes. Instead, call a licensed plumber or water damage restoration professional for expert advice on how to repair your slab leak. 

How SERVPRO Can Help 

You never want to find the pipes beneath your foundation leaking, but these things happen. The key is to bring in a professional slab leak repair team as soon as possible to limit the damage to your home. 

If you do have water damage to your floors, walls, or belongings, don’t ignore it. Lingering moisture can damage your home’s structural integrity and invite mold.  

SERVPRO specializes in water damage restoration following a slab leak or other unexpected events. Our trained professionals can extract water, dry affected areas, and help restore your home to its original condition. Find a location near you for fast, reliable service. 

FAQs

Still have questions about slab leak repair? Here’s what you need to know when dealing with a leak beneath your foundation.  

What are the signs of a slab leak?

Warning signs of a slab leak may include unexpected increases in your water bills, damp or warm spots on your floors, the sound of running water when fixtures aren’t in use, reduced water pressure, and cracks in the walls or flooring. You may also notice mold growing in your home or a musty odor near the leak. 

How do professionals find a slab leak?  

Slab leak repair professionals typically use noninvasive tools to pinpoint the leak, such as acoustic listening equipment to detect water movement, infrared cameras to find temperature differences, and pressure testing to confirm a leak in the system. Accurate detection helps determine the best repair option and limits unnecessary damage to your home.  

<Is slab leak repair covered by homeowners insurance?

It depends on your policy and what caused the leak. For example, your homeowners insurance policy might cover water damage caused by a sudden slab leak, but not damage caused by long-term, gradual leaks. The best move is to document what you’re seeing and any repair estimates and contact your insurer to understand what’s covered.  

How long does it take to repair a slab leak?  

Most slab leak repairs can take a few hours to a few days, depending on the repair method. Trenchless repair and pipe re-routing are often completed faster, while under-slab tunneling or breaking through the slab may take longer due to excavation, concrete work, and flooring restoration. If there’s water damage, drying and restoration can add more time.