If you’re wondering what belly in the sewer line is and how a repair is done, this guide is for you. Suffice to say, a belly in your sewer line is a big problem. Ignoring one can lead to severe consequences for your plumbing and the soil surrounding your home.

What Is a Sewer Line Belly?

When a plumber finds a belly in sewer line repair inspections, they are referring to a sag or low spot in the pipe. The pipe is still intact, in contrast to channeling in which the bottom of it has eroded away. A bellied pipe no longer has a positive slope. It bows downward (negative slope), allowing water to pool or debris to collect in the low area, which can continue to accumulate and cause a sewer line blockage. Sewage may then back up.

Normally, a sewer pipe has a positive slope that transports waste away from your home using the force of gravity. The guidelines for sewer line design are quite specific; a sewer pipe must decline at least 0.25 inches per every foot of horizontal distance. This guarantees gravity can move wastewater into the municipal sewer line, but a belly disrupts this process as the slope is no longer adequate.

Cast iron is difficult to bend except for under intense pressure. A belly therefore most often occurs at the fitting. While most water may flow over and past the belly at first, what remains trapped can collect additional material. It, along with the stagnant water, restricts flow within the pipe and causes solids to accumulate.

What Causes a Belly in a Sewer Line?

A variety of factors can contribute to a belly forming in a sewer pipe. The most common causes include:

  • Soil erosion
  • Shifting ground material
  • Foundation settlement
  • Earthquakes
  • Extreme heat
  • Heavy rain
  • Loose material around the pipe
  • Pressure from tree roots
  • A broken pipe joint
  • Poor installation
  • Improper soil compaction at installation site

However, bellies can be prevented first by installing the proper bedding material during a plumbing job. The correct size and grade of material can prevent settling. A professional must also ensure the correct slope during installation so that waste doesn’t build up and cause excessive localized pressure that can cause sagging. Ground stability and support for pipe are also key considerations during installation.

How Do I Know There’s a Sewer Line Belly?

A certified plumber can use video inspection to identify the problem. A video camera is pushed through the line so the technician can see the inside of the pipe on a monitor. Cracks, holes, clogs, and slope problems can be instantly identified. Sometimes, bellies don’t cause immediate sewage problems, and homeowners choose to leave them alone. But if the problem worsens, it cannot be ignored; extreme anomalies can cause wastewater to back up into your home.

How to Fix a Belly in Sewer Line Repair

The approach to repair varies with each case. Oftentimes, a conventional method is required to correct the slope of the pipe. Trenchless pipe bursting or replacement isn’t always recommended, because the ground beneath the sagging sewer line needs to be filled and stabilized. This involves extensive digging. But it allows a technician to fill loose ground, compact the soil, reinforce pipe joints, and perform other work to ensure the line is secure and meets the latest codes.

Contact Express Plumbing Heating & Air

Customers throughout Boise and the Treasure Valley depend on us for all types of piping services. We can quickly assess your sewer line if you suspect a problem. When excavation service is required, we focus on planning, preparation, and effective management. Sewer line repair and replacement is a job for the experts. Call (208) 398-0309 or book an appointment online to have our skilled technicians visit your home and explain the options.

Express Plumbing Heating & Air

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