# How is pipe cleaning with a water jet done?

Source: https://cantleyvidanjoraltyapi.com/en/blog/water-jet-pipe-cleaning/

Published: 2026-10-17

## In short

- A water jet pulls itself forward and cleans the pipe wall at the same time, using water that sprays backwards and forwards from the nozzle on the end of the hose.
- The hose usually enters through a manhole or an access point, and the line is cleaned against the direction of flow.
- Grease and sludge coat the whole circumference of the pipe, so a jet that washes the wall from start to finish gives a more lasting result than a snake that only punches a hole.
- In cracked or badly thinned old pipes, the pressure is chosen to suit the condition of the pipe, and a camera is sent in first if needed.
- A working jet hose is never held by hand, and the nozzle is never pulled out of the pipe while the water is on.

Water jet pipe cleaning means sending high-pressure water from a pump into the pipe through a flexible hose and the nozzle on its end. This strips off the grease, sediment and sludge stuck to the walls and carries it down the line. The work is done through an existing opening, so no floor or wall needs to be broken.

Many people who hear about the method assume it is just squirting water into a blocked pipe. In fact, the choice of nozzle, the point where the hose goes in, the pressure being set to suit the pipe and the check at the end of the job decide how lasting the result will be.

## How does the nozzle move the hose along the pipe?

The metal head on the end of a jet hose has small holes. Most of them face backwards, in the direction the hose comes from. The water spraying backwards pushes the head forward, so the hose pulls itself along the pipe, and at the same time those jets sweep the pipe wall in a ring. A single forward-facing hole breaks through any blockage ahead and opens a path.

As the hose is slowly drawn back, the rearward jets gather everything that has come loose and push it down the line. For this reason jetting is not a single push: the same section is cleaned back and forth several times.

## Which nozzle is used for which job?

Different nozzles are fitted depending on the diameter of the line, the type of blockage and the pipe material. If the wrong head is chosen, the water either cannot get through the blockage or passes over the wall without cleaning it properly.

- Penetrating nozzle: a strong forward jet with supporting rear jets opens a path through a packed blockage.
- Cleaning nozzle: wide jets facing only backwards and sideways strip the sediment from the wall and carry it away.
- Rotating nozzle: it spins on its own axis and scrapes the layer of grease and limescale evenly around the pipe.
- Root-cutting head: blades turned by the force of the water cut fine roots that have grown into the pipe.
- Thin hose and small head: used at low pressure in the narrow PVC drain lines inside a building.

## Where does the hose go into the line?

On lines outside the building, the entry point is usually a manhole or inspection chamber. The hose is sent from the manhole up towards the building, and the line is cleaned against the direction of flow. This way the grease and sludge that come loose always flow towards the manhole and are never pushed back into the building. Once the manhole cover is open, nobody goes down inside, and the hose is guided from the edge.

Inside the building, the access points on the shared stacks or horizontal lines are used. If there is no access point, the line can be reached by removing the sink trap or through the connection under the toilet, but large heads are not passed through narrow traps. The crew decides during the survey which end of the line is safer to clean from.

## Why is a water jet more lasting on grease and sludge?

Blockages in kitchen and sewer lines often do not come from a single object. They are made of a layer that wraps the whole inner circumference of the pipe. A motorised drain snake bores a hole through the middle of this layer and the water starts to flow again, but because the grease on the wall stays in place, the hole closes up again quickly.

A water jet washes the wall all the way round and carries the loosened material away with the water. The pipe returns to a width close to its inner diameter, which means the next build-up forms later. For a hard object, such as a toy or a piece of cloth that has got lodged in the pipe, a snake or a robot may be more suitable, and the two methods often complement each other.

## Can old and worn pipes withstand jetting?

In sound pipes, a correctly set water jet is a safe cleaning method, and no tool that scratches or scrapes the pipe is used. The risk appears in lines that are already damaged. Cast iron pipes with fine cracks or with an inner surface rusted paper-thin, and old clay pipes with slipped joints, can suffer more damage under high pressure.

For this reason an old line should first be inspected with a camera, and the pressure should be lowered to suit the condition of the pipe. If a section has collapsed or is badly cracked, jetting will not solve the problem, and replacing that part through line renewal comes up for discussion.

## Why is a camera sent in after jetting?

Water flowing again does not mean the line is completely clean. The camera shows whether any layer is left on the wall of the jetted section, why the sediment built up there and what the general condition of the pipe is. Often the real cause of a repeated blockage is also seen at this stage: a sag where water collects, roots that have grown in or a slipped joint.

The footage is shown to you as well. That way you can see with your own eyes whether the line only needs cleaning or whether a section has to be repaired, and decide accordingly.

## What to watch for while the jet is running

High-pressure water at the end of the hose is strong enough to cut skin and force water under it. The rules the crew follows during jetting are simple precautions that the homeowner or business owner should know as well.

- A working hose and nozzle are never held by hand, and nobody looks into the mouth of an open pipe.
- The nozzle is not pulled out of the pipe while the water is on, otherwise the hose whips around out of control.
- Toilet lids connected to the line being cleaned are closed, and floor drains are covered.
- Children and pets are kept away from the open manhole and the work area.
- Gas can build up inside a manhole, so nobody goes down into it.

## Frequently asked questions

### Can a water jet be used in a sink pipe at home?

Yes, it can be used at low pressure with a thin hose and a small head. For a hair or soap blockage in a single sink, a snake is often enough. Jetting is preferred more on greasy kitchen lines and long horizontal pipes.

### Do tiles get broken during water jet cleaning?

No. The hose goes in through existing openings such as a manhole, an access point or a trap connection. Breaking only comes up if the camera shows a collapsed section and that section cannot be renewed any other way.

### Can water be used in the home while the line is being cleaned?

The drains connected to the line being cleaned should not be used. Running water makes it harder for the loosened sediment to be carried down the line and can send dirty water back up through the lowest drain.

### Does a water jet clear roots that have entered the pipe?

Fine roots can be cleared with a root-cutting head. Thick and dense masses of roots need a mechanical cutter. If the joint where the roots entered is not repaired, they will grow back, so a camera check is essential.

## Have your line cleaned with pressurised water

If you want your grease-coated or sludge-filled line cleaned, call 0212 923 66 85 or send a short description of the situation on WhatsApp. We do the jetting without breaking tiles or walls and show you the result on camera.

Phone: 0212 923 66 85 (tel:+902129236685)  
WhatsApp: https://wa.me/905315687185