Drain School · Reference
Drain & sewer, translated.
Every term a drain tech might say to you, defined the way we would say it standing in your yard.
- Lateral (sewer lateral)
- The buried pipe that carries everything from your house to the city main. It is yours — the city's responsibility usually starts at the main, which is why lateral repairs land on homeowners.
- Main line
- The largest drain pipe in your home, collecting from every fixture before leaving the house. When several drains act up at once, the main line is the suspect.
- Branch line
- The smaller pipe serving one fixture or one area (a bathroom group, the kitchen). A single slow fixture usually means a branch-line problem.
- Cleanout
- A capped access pipe — typically near the foundation or in the yard — that opens directly into the sewer line. It is where cameras and jetters go in without touching a toilet.
- Sewer scope / camera inspection
- Running a waterproof video camera through the line to see its real condition. The basis of every honest sewer quote.
- Hydro jetting
- Cleaning a pipe with high-pressure water that scours the full interior wall — removing grease, scale, and roots rather than punching a hole through them.
- Cabling / snaking
- Driving a rotating steel cable through a clog to open a channel. Quick and fine for one-off blockages; leaves wall buildup behind.
- Milling / descaling
- Mechanically cutting hardened scale, mineral buildup, or failed liner material out of a pipe to restore its original diameter.
- Epoxy brush coating
- A trenchless repair that applies structural epoxy to the inside of a cleaned pipe, sealing cracks and corrosion — no digging.
- Trenchless
- Any repair done from inside the pipe through existing access points, leaving the yard, driveway, and landscaping intact.
- Belly (sag)
- A low spot where the pipe has settled. Water pools there, solids collect, and clogs repeat until the sag is addressed.
- Offset joint
- Pipe sections pushed out of alignment by ground movement, leaving an edge that snags debris and a gap that leaks.
- Root intrusion
- Tree roots growing into a line through joints or cracks in search of water. The classic cause of recurring clogs in established neighborhoods.
- Scale
- Rough rust and mineral buildup inside older pipes — especially cast iron — that narrows the line and catches paper.
- Orangeburg
- Bituminized-fiber pipe used in mid-century construction. It softens and deforms with age; if a scope finds it, plan for replacement.
- P-trap
- The curved pipe under fixtures that holds water to block sewer gas. A dry trap is the innocent explanation for a sewer smell.
- Backflow / backup
- Wastewater reversing into the home — usually at the lowest drain — because the line downstream is blocked. An act-now situation.
- Locating
- Tracing the camera head from the surface to mark a problem's exact position and depth — the reason a repair is one hole, not an excavated yard.
Seeing one of these signs?
A camera pass settles it — no guessing, no scare quotes.