Pipe cleaning glossary

A–ZTerms

ABS

Acrylonitrile butadiene styrene, the black plastic pipe widely used for residential drain, waste and vent piping in Canada. Smooth, corrosion-free, sensitive to heat and sharp cutters.

Asbestos-cement pipe

Grey cement pipe reinforced with asbestos fibre, used for some mid-century mains and laterals. Looks like concrete; must not be cut, drilled or broken without professional handling.

Auger (drain snake)

A coiled steel cable spun by hand or machine to bore through, grab or cut a blockage. Opens a path through a clog but does not clean the full pipe wall.

Backwater valve

A one-way valve in the building drain that closes when sewage flows backward from the main, protecting fixtures below grade. Needs periodic cleaning and must be accessible.

Belly (sag)

A section of pipe that has sunk below its intended slope, so water and solids pool there. Causes repeated buildup that cleaning manages but does not fix.

Building drain

The horizontal drain inside the building that collects waste from stacks and branches and carries it to the building sewer.

Building sewer (lateral)

The pipe that carries waste from the building to the municipal main or a private sewage system. Often vitrified clay in older Canadian homes.

Bulb head

A rounded auger head that follows bends and bores through hair and soft clogs. The gentlest common head and the usual choice for fixture drains.

Camera inspection

Recording the inside of a pipe with a push or crawler camera to identify material, deposits and defects. The step that decides the right cleaning method for older or recurring problems.

Carbide head

A descaling head with tungsten carbide cutting surfaces used for hard scale and tuberculation. More aggressive than a plain chain.

Cast iron

Heavy iron pipe used for drains, stacks and vents in Canadian houses for much of the 20th century. Corrodes internally and develops tuberculation.

Chain knocker

A descaling tool made of chains on a spinning hub, driven by a flexible shaft. The flailing chain knocks scale and hardened deposits off the pipe wall.

Channel rot

Corrosion that eats a groove or open trough along the bottom (invert) of horizontal cast iron pipe. A repair finding; cleaning cannot restore missing metal.

Chemical drain opener

A consumer or commercial product using caustic, acid or oxidizing chemicals to dissolve clogs. Hazardous to people and to old pipe, and rarely effective on main lines.

Cleanout

A capped access fitting that lets cleaning equipment enter the drain system. Found at stack bases, on building drains, outside the foundation and on some branches.

Closet auger

A short, rigid-handled auger with a protective sleeve designed to clear toilet trapways without scratching porcelain.

Cured-in-place pipe (CIPP)

A resin-saturated liner inserted into a cleaned host pipe and cured to form a new pipe inside the old one. Needs a host pipe that still holds its shape.

Descaling

Mechanical removal of hard deposits such as tuberculation, mineral scale and calcified grease, usually with chain or carbide heads, followed by flushing.

Ductile iron

Iron treated with magnesium so its graphite forms spheres, making it tough enough for pressure water mains. Usually cement lined; rarely found inside houses.

DWV

Drain, waste and vent: the part of a plumbing system that carries wastewater away and lets air in and out.

Enzyme cleaner

A drain product containing enzymes or enzyme-producing bacteria that slowly digest organic films such as grease. A maintenance tool, not a clog remover.

Flushing nozzle

A jetter nozzle with rear-facing jets that pull the hose forward and sweep debris back toward the access point as the hose is retrieved.

FOG

Fats, oils and grease: the main cause of kitchen drain buildup. Cools and coats pipe walls in layers.

Galvanized steel pipe

Zinc-coated steel pipe used for some older branch drains and vents. Corrodes internally as the coating wears; walls can become thin.

Grabber head

An auger head with hooks or springs designed to catch and retrieve an object or a mass of hair rather than bore through it.

Graphitic corrosion

Corrosion of grey cast iron in which the iron leaches away and leaves a graphite skeleton that keeps its shape but has little strength.

Hub (bell)

The enlarged end of a cast iron or clay pipe section into which the next section fits. Hubs and joints are common snag points for cutters.

Hydro jetting

Cleaning a pipe with high-pressure water through a nozzle that propels the hose and scours the full pipe wall. Best for grease, sludge, sand and soft roots.

Injection injury

An injury in which high-pressure water or fluid is forced under the skin. Can appear minor but needs urgent medical care.

Invert

The inside bottom of a pipe, where wastewater flows. The part of horizontal cast iron that wears first.

Jetter

The machine that pumps water at high pressure through a hose and nozzle for hydro jetting. Rated by pressure (psi) and flow (litres or gallons per minute).

Lead and oakum joint

The traditional cast iron hub joint: tarred hemp or jute fibre packed into the hub, then sealed with poured and caulked lead. Lead matters when the joint is cut or heated.

Main (sewer main)

The municipal sewer pipe under the street or lane that collects flow from many laterals. Usually the municipality's responsibility.

No-hub coupling

A neoprene sleeve held by a stainless steel band and clamps, used to join plain-end cast iron pipe or to connect cast iron to plastic.

Offset joint

A joint where two pipe sections no longer line up, leaving a lip. Catches debris and can snag cutters.

Orangeburg pipe

Bituminized fibre pipe made of wood pulp and pitch, used for some sewer laterals in the mid-20th century. Softens and deforms with age; cleaned only gently if at all.

P-trap

The U-shaped section under a fixture that holds water to block sewer gas. The most common location for fixture clogs.

Pig (pipeline)

A device pushed through a pipeline by the fluid behind it to clean deposits, remove water or inspect the wall. Used in transmission lines, not house drains.

PSI

Pounds per square inch, the pressure unit used for jetters. Pressure cuts; flow carries debris away.

PVC

Polyvinyl chloride, the white or cream plastic pipe used for drains and sewers. Smooth and corrosion-free; more brittle in extreme cold.

Root cutter

An auger head or jetter nozzle designed to cut roots inside a pipe. Sized below the pipe diameter to avoid catching at joints.

Root intrusion

Roots growing into a pipe through joints or cracks and forming a mass that catches debris. Common in clay laterals.

Rotating nozzle

A jetter nozzle whose jets spin, scrubbing grease and scale from the full wall more thoroughly than a fixed nozzle.

Scale

Hard mineral deposits left by water, especially hard water, where it sits or evaporates. Found in toilet traps, fixture drains and old metal pipe.

SDR (standard dimension ratio)

A pipe's outside diameter divided by its wall thickness. SDR 35 is a common rating for buried PVC sewer pipe, often green or cream.

Sectional machine

An auger machine that uses short, joined cable sections rather than one long coiled cable. Used for larger mains and long runs.

Sewer gas

The gas mixture from decomposing waste, which can include hydrogen sulphide and methane. Blocked by trap water and carried away by vents.

Soap scum

Insoluble deposits formed when soap reacts with calcium and magnesium in hard water. Binds hair and lint into firm clogs.

Sonde

A small radio transmitter on or near a camera head that lets an operator locate the camera's position and depth from the surface.

Spade cutter

A flat, bladed auger head that cuts through soft clogs and light roots. Should be sized one step below the pipe diameter.

Stack

A vertical drain pipe carrying waste down through the building. The main stack continues up through the roof as the vent stack.

Standpipe

The open vertical drain pipe, with a trap below it, that a washing machine hose discharges into.

Trap arm

The horizontal pipe between a fixture trap and the drain or stack. Often the access point for cleaning a kitchen branch.

Tuberculation

Hard, rounded rust nodules that grow on the inside of iron pipe, narrowing the bore and catching debris. Removed by descaling.

Vent

A pipe that lets air into the drain system to prevent traps being siphoned and lets sewer gas escape above the roof.

Vitrified clay pipe

Fired ceramic pipe used widely for sewer laterals. Very hard and chemical-resistant; vulnerable at joints and to roots and soil movement.

Weeping tile

Perforated foundation drain pipe laid around the footings to carry groundwater to a sump pit or, in some older homes, the sewer.