How to Repair Sewer Lines Under a Concrete Slab

The words broken sewer line are hard enough to hear as a home or business owner. The phrase is even more offensive when it is accompanied by underneath the concrete. Hopefully, hearing these words means the break is only below the sidewalk out front. But oftentimes it means the break is beneath the property – which is built on a slab foundation. Buildings built on slab foundations do not have basements or crawlspaces. When a drain pipe breaks below the slab, location and repair can be difficult. But not always. Below we will outline the traditional method for searching and replacing broken pipe below a concrete slab, and then tell you how Pipelining Technologies, Inc. does it.

The Traditional Method:

Locating a Leaking Pipe Below Cement

Cement is porous and will absorb leaking water and wick it toward the surface. Because of this, you will be able to physically see the leak, as water will be infiltrating your floors. You will find one or more of the following in your home: 

  • Wet or damp carpet
  • Mildew or mold under carpets, rugs, or flooring
  • Visible pools of water

Dependent upon the age of the leak, the water will either be visible just above the leak, or, if older, the water will have spread and the leak’s location will be less detectable. Above-ground listening devices can help professionals pinpoint the exact location(s) of the leak. 

Excavating Flooring & Slab to Replace and Lay New Pipe

Traditionally, excavation follows leak detection. This includes digging inside your house (or under if the leak is just inside the perimeter), repairing or replacing the broken pipe, refilling the groundwork beneath the slab, relaying concrete, and reinstalling your flooring. Cleanup throughout is extensive, as jackhammering concrete creates dust that can settle throughout the home. This method comes with concerns. 

Apart from the obvious disadvantages of inconvenience, high labor costs, and maintenance associated with chiseling through your floors, there is also a concern of whether the structural integrity of the house will withstand the disruption. If the broken pipe requires multiple points of entry, or an entry point that is large, the resultant damage to the foundation of your house is equally large, and can leave you with an unsafe structure – even after new concrete is poured.

The Trenchless Pipelining Method

Finding and repairing a broken sewer line under your slab-built home is streamlined and low-impact when you employ the technologies available through Pipelining Technologies, Inc. Three simple steps include: 

  1. Diagnostic Video Camera Sewer Pipe Inspection 
  2. Mechanical Cleaning & Descaling 
  3. Precision Pipe Lining with Robotic Branchline Reinstatements


To start, a trenchless pipe repair expert will perform a video inspection, entering through a common access point such as a bathtub drain. The video produces a full-color digital view of the diameter of the pipes, the lengths, materials, and branchline locations that comprise your sewer lines. (Branchline refers to the connections among sewer lines that create a large network of pipes). This video is used to create a full-scale map of your pipework so that pipelining materials can be designed and developed specifically for your home.

Once the pipes are charted and problem areas are identified, methods to clean the interior of the pipes are employed. Mechanical cleaning and descaling remove blockages such as oil/grease buildup, tree roots, and heavy corrosion. This method uses both wet and dry methods of cleaning and restores the pipes’ original diameter. 

Once the pipes are cleaned out and their interiors are as smooth as they can be, re-lining the pipes begins. Custom liners are built to fit inside the existing pipelines. The material is malleable and flexible enough to fit into your pipes through small access points or your outside plumbing cleanout. The liner is then pushed through the entire length of the pipe and given time to cure, or harden. The new, hard liner becomes your new pipe – without cutting, patching, or cleaning up cement dust. 

Lastly, thanks to the mapping performed in step 1, the technicians are able to open up all branchline connections via robotic instruments that move through the drainage system remotely.

This method is as non-invasive as it sounds, allowing you to remain in your home through the entire process. There is no concern for mess and debris related to cutting through floors, and no worry over foundation damage from breaking open the slab. And the replacement materials are known to last upwards of 50 years. 

If you are facing a sewer line leak under your cement foundation home, reach out to Pipelining Technologies to discover how our professional technicians can help you navigate repairs. A Florida State Certified Plumbing Contractor, we are licensed, insured, and permitted plumbing contractors that specialize in trenchless sewer repair and have been helping homeowners and businesses remedy pipe degradation and breaks for more than 35 years.

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