A drain rod can clear most blocked drain call-outs. You push the rod down the pipe, turn it against the blockage and break it up. Rodding is quick, cheap and fine for a simple grease plug or a ball of hair near the access point. Yet it has hard limits. Knowing them is the difference between a drain that stays clear for years and one that blocks again in weeks. High-pressure jetting deals with what rodding cannot reach.
How Rodding Works, and Where It Fails
A drain rod is a flexible fibreglass section with threaded connectors, so you join several sections and push them into the drain. You then turn them against the blockage to break it up. The push of the rod end does the work.
Because it is simple, rodding is effective against these blockages.
- Soft blockages close to the access point, such as grease, hair and food debris
- Toilet paper packed in the soil stack
- Light root feeders near a joint
Yet rodding fails against these problems.
- Grease-coated pipe walls. A rod can break the plug in the middle of the pipe, yet it leaves the fat on the walls. That layer catches new debris, so the drain blocks again within days.
- Scale and mineral deposits. Hard water scale narrows the pipe slowly. A rod passes through the gap and cannot remove the deposit.
- Root intrusion. A rod cannot break up roots that have spread along several metres of pipe. Trying it risks snapping the rod.
- Blockages in long runs. Rodding weakens the further you go from the access point, because friction builds up on the rod.
- Offset joints and pipe defects. At a dropped joint, a rod may push debris into the soil instead of the sewer.
How High-Pressure Drain Jetting Works
A jetting unit pumps water at high pressure, set to suit the pipe size and the blockage type. The water flows through a flexible hose to a purpose-built nozzle. Forward jets cut into the blockage, while rear jets push the hose along the pipe.
The rear jets are the key. While a rod is pushed from outside, a jetting hose pulls itself forward with its own thrust. So it can travel a long way from the access point. It goes round bends and through chambers, and along runs that no rod could reach.
The forward jets cut the blockage while the water scours the walls and removes the grease coating, scale and debris that caused it. The cleared material washes on to the next chamber. There it can be removed, or broken into small pieces that pass through to the Thames Water sewer.
Since kit matters, visit our drain jetting service page for more on what we use and typical jetting jobs.
When Jetting Is the Right Call
Recurring blockages. If the same drain blocks every few months after rodding, the cause is still there. Jetting cleans the walls, so it removes the conditions that cause re-blocking.
Grease-dominated blockages. Kitchen drains in London, especially in the Victorian terraces of Camden, Islington and Hackney, gather grease over years. Although a rod will not shift it, a jet will. See our post on why Camden, Islington and Hackney kitchens block most often.
Root intrusion. Root-cutting nozzles spin fast and cut through the root mass, while they then flush the debris clear. For established roots, jetting is the only option short of digging.
Pre-relining preparation. If you are having a pipe relined, jet it clean first, because debris or grease on the wall will stop the liner bonding.
Commercial properties. Restaurants and hotels gather grease faster than homes do. Regular jetting is standard upkeep there, so see our commercial drain jetting guide for advice on how often.
Jetting Pressures and Pipe Age
Owners of old Victorian clay pipes often ask whether jetting will damage them. Although it is a fair question, the answer depends on technique.
Modern kit lets the engineer adjust pressure and flow to suit the pipe. A sound Victorian clay pipe can take standard jetting without damage. A pipe with big cracks, slipped joints or missing sections is a different case, because strong jets can widen a crack or move a section.
For this reason, a responsible contractor surveys the pipe before jetting if it has a history of trouble, or if it is very old, since the survey finds structural defects before the jet does more harm. Our post on domestic drain jetting for old pipes covers this in more detail.
How Much Does Drain Jetting Cost?
The cost of a home jetting job in London depends on access, the length of the run and how bad the blockage is, while emergency call-outs carry a premium. Our full breakdown is on the drain jetting cost page. It also shows what drives the gap between a simple job and a complex one.
Frequently Asked Questions
Can I hire a jetting machine myself?
You can hire a domestic jet washer, but it is not the same as professional drain jetting kit. Professional jetting uses nozzles and flow rates matched to the pipe size. Because the wrong kit can shove a blockage deeper into the pipe, it is safer to use a professional.
How long does a drain jetting job take?
A simple home job with one blockage and one access point is quick, while longer commercial runs or complex root-cutting jobs take longer.
Will jetting damage my pipes?
On sound pipes, no, although on pipes with cracks or slipped joints, high pressure can make the defect worse. That is why a CCTV check before jetting matters for older homes.
How often should I jet my drains?
Most homes do not need routine jetting, only when a blockage occurs. However, homes with mature trees overhead, commercial kitchens and homes with repeat blockages can gain from regular preventive jetting.
Do you cover the whole of London?
Yes, since you can request a quote online via our contact form or visit our drain jetting service page to arrange a visit across Greater London.
Because every property is different, start with our guides to high-pressure drain jetting and pre-purchase drain survey advice. We also cover high-pressure drain jetting in Haringey and high-pressure drain jetting in Islington, so you can see how the work runs near you.
