A homeowner’s resource for main line & sewer clean-out, repair, and replacement terms commonly used and their associated meanings.



ABS or acrylonitrile butadiene styrene is a plastic material similar to PVC, except it is more likely to warp and deform when exposed to sunlight. ABS was a popular material for main line pipes built in the 80s


Access Tunnel

A tunnel dug underneath a home, allowing plumbers to access areas of the main line that need repair.


Bell and Spigot

A type of concrete pipe found in older main line drainage systems. These pipes flare into a bell shape at one end where they are loosely connected with the other end of another concrete pipe and concrete sealed.


Belly or Bellied Pipe

When there is a dip in a sloped main line that creates a low spot, forcing sewage to travel upwards for a segment of pipe. Bellied pipes can cause a main line stoppage.


Channel Rot

When the bottom of a cast iron drain line or main line rots all the way through, which causes your home’s sewage to build up in the ground, eventually causing a main line stoppage.


Cast Iron

A hard, yet relatively brittle alloy composed of iron and carbon. Cast iron was used for main lines built before the 80s.


Drain Line

Sewage pipe that connects a drain to the main line.



Concrete anchors used to hold a concrete slab in place. Sometimes the weight of footers can push main line pipes down in certain areas causing a belly to form.



A special cable that sprays water at up to 4000 PSI (as needed) used to clean off grease and other build-up found inside a sewage pipe.


Main Line

The sewage pipe that all the drains in your home tie into. The main line should bring all the water and waste that you flush down your toilets, sinks, showers, and tubs to your neighborhood and city sanitation system.


Main Line Stoppage

When there is an obstruction in the main sewer line that prevents water from draining and causes a back up.



A misaligned concrete bell and spigot concrete pipe connection.

  • Negative Offset – An offset that creates a step-up, which causes water to build up in the offset area of the pipe.
  • Positive Offset – An offset that creates a step-down, creating a waterfall effect that allows the waste water to keep moving down the pipe.


PVC or Polyvinyl Chloride is a plastic polymer commonly used for potable water and sewage pipes. PVC pipes are rated by different “schedules” that relate to the wall thickness of a pipe. John Moore uses schedule 40, solid core PVC pipes when replacing main lines.


Sewage Backup

When sewage water comes back up through a drain because there is a stoppage in the main line. For instance, if you flush your toilet and sewage water comes up through your tub or shower drains.


Spot Repair

When just a small section of pipe is repaired or replaced.


Slope or Fall

The downward angle of a main line so that sewage water can easily slide down the pipe and to the public sanitation system.


Snake Cable

A special cable used to poke a hole in a main line stoppage. There are several attachments we use:

  • Spearhead – A point added to the end of a snake cable to easily cut through grease and buildup.
  • Cutter Blade – A saw-like attachment used to cut, pull, and saw through tree roots in a main line.

Root Ball

A large clump of tree roots, typically resulting from tree roots that have previously been cut and grow back twice as thick.


Two-way Cleanout

A covered hole on the outside of your home that allows a plumber or drain service person to access the drain line.

(877) 730-2525

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