Sewer Line Replacement in The Colony, Texas: Correcting a Failed Under-Slab Sewer Connection

Written by Steven Shipler, Texas Licensed Master Plumber, Responsible Master Plumber (RMP), MBA, and host of The 4 Guys Education on YouTube.

Many sewer line problems are hidden beneath the slab foundation where homeowners cannot see them. In this project in The Colony, Texas, we were called to evaluate and repair a damaged section of sewer piping beneath the home that had lost alignment after movement in the foundation and surrounding soil.

The sewer line had separated beneath the slab, preventing proper drainage and creating the potential for recurring backups, standing water, and long-term structural concerns. After exposing the pipe and evaluating the condition of the sewer system, we replaced the damaged section and restored proper flow.

What We Found Beneath the Slab

After opening the repair area, we discovered that the existing sewer connection had separated beneath the foundation. The photographs show a clear gap between the sewer fittings and drain line sections.

This type of failure commonly occurs after:

• Foundation movement
• Settlement of supporting soils
• Improper original installation
• A previous foundation lift
• Long-term stress on the pipe system
• Poor support beneath the drain line

Once a sewer line separates, wastewater can escape into the surrounding soil and the pipe can lose the proper slope needed for gravity drainage.

The Challenge of Under-Slab Sewer Repairs

Under-slab sewer repairs are among the most difficult plumbing repairs because the damaged piping is buried beneath concrete foundations.

To access the failed section, we carefully excavated the area and exposed the damaged fittings. The repair required working in a confined excavation beneath the slab while preserving structural support and creating enough access to rebuild the sewer connection correctly.

Unlike a simple drain cleaning, an under-slab sewer repair requires evaluating:

• Pipe alignment
• Pipe slope
• Structural integrity
• Foundation conditions
• Future serviceability
• Long-term drainage performance

Rebuilding the Sewer Line

After removing the failed section, we installed new PVC sewer fittings and re-established proper flow through the system.

The completed repair included:

• Removal of damaged piping
• Installation of new PVC fittings
• Correction of alignment issues
• Restoration of proper sewer slope
• Fernco shielded couplings where appropriate
• Testing of the repaired section

The final assembly restored continuity between the bathroom drain group and the main sewer line while maintaining the proper grade required for wastewater flow.

Signs You May Have a Similar Sewer Problem

Many homeowners experience symptoms long before the actual sewer failure is discovered.

• Recurring drain backups
• Slow-draining fixtures
• Gurgling toilets
• Sewer odors inside the home
• Foundation repair history
• Frequent drain cleaning needs
• Standing water in a sewer inspection video
• Backups affecting multiple fixtures

The only way to know what is happening underground is through a sewer camera inspection.

Watch Real Sewer Inspection Videos

See actual sewer inspections and narrated plumbing evaluations from North Texas homes.

Why Sewer Inspections Matter Before Buying a Home

Many sewer failures remain hidden until after closing. A sewer camera inspection can reveal:

• Pipe separations
• Broken sewer lines
• Standing water
• Sewer bellies
• Root intrusion
• Cast iron deterioration
• Improper slope
• Offset joints
• Previous repairs
• Potential future failures

The inspection provides visual evidence that allows buyers and homeowners to make informed decisions.

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