What Is Drain Jetting and How Does It Work?

Drain jetting — also called hydro-jetting — uses a specialised pump to force water through a hose at extremely high pressure. The hose ends in a nozzle with jets that point both forward and backward. The forward jets break up the blockage, and the backward jets propel the hose further into the pipe while simultaneously scouring the pipe walls clean.

It’s not the same as the pressure washer you use to clean your patio. A domestic pressure washer runs at around 100 to 150 bar. A professional drain jetter runs at 250 to 300 bar — and the flow rate is much higher. That combination of pressure and volume is what makes it effective. The water doesn’t just push the blockage through; it breaks it apart and washes it away. The result is a pipe that’s restored to its full internal diameter, with no residue left behind to cause another blockage next week.

For most blockages in Bexley — whether it’s a grease buildup from a kitchen, silt washed into the drains after heavy rain, or the early stages of root ingress — drain jetting is the right first tool. It’s fast, it’s non-invasive, and it doesn’t require digging up your garden or your driveway.

Why Bexley’s Drains Need Jetting More Than You’d Think

Bexley is a big borough — it stretches from the Thames at Erith and Belvedere all the way down to the Kent border near Sidcup and Foots Cray. The drainage challenges vary a lot depending on which part of the borough you’re in.

In the northern parts — Erith, Belvedere, and Thamesmead — the ground is mostly alluvial soil and gravel from the Thames floodplain. The water table is high, and the drains are prone to silt buildup. Every time there’s heavy rain, surface water finds its way into the drainage system through cracked inspection chambers or poorly sealed manhole covers, carrying fine silt and grit with it. Over time, that silt settles in the bottom of the pipe and reduces the flow. Eventually, it builds up enough to cause a complete blockage. Drain jetting is the only reliable way to shift that kind of accumulated silt — rods just push through it and leave most of it behind.

In the central and southern parts — Bexleyheath, Welling, Sidcup, and Blackfen — the housing stock is mostly 1930s semi-detached and detached houses, built on London Clay. The same clay that causes ground movement and pipe displacement in other parts of South London is a problem here too. The old salt-glazed clay pipes that were standard in the 1930s are brittle, and the joints are rigid. When the clay shrinks in summer and swells in winter, the pipes shift. That creates dips in the pipe run where debris collects, and it opens up gaps at the joints where tree roots get in. A jetting nozzle with a root-cutting attachment can clear the roots and wash out the debris in one pass.

And then there are the trees. Bexley is one of the leafiest boroughs in London — Danson Park, Foots Cray Meadows, Hall Place, and the dozens of green spaces mean there are mature trees everywhere. Tree roots are the single biggest cause of recurring blockages in Bexley, and drain jetting with a root cutter is the most effective non-invasive treatment.

When to Call for Drain Jetting — and When Not To

Drain jetting is brilliant for most blockages, but it’s not the right tool for every situation. Here’s when it works and when it doesn’t.

Jetting is ideal for:

• Grease and fat blockages. Bexley has a lot of family homes with busy kitchens, and cooking fat poured down the sink is the number one cause of kitchen drain blockages. Jetting blasts the grease off the pipe walls completely — unlike chemicals that just dissolve the surface layer.
• Silt and debris. In the northern parts of the borough near the Thames, silt buildup is a constant problem. Jetting flushes it all out.
• Tree roots. A root-cutting jetting nozzle can shear through roots up to about 25mm thick. For thicker roots, we might need to use a mechanical cutter first, but jetting is still the best follow-up to clean the pipe.
• Scale buildup. In areas with hard water — and Bexley’s water is moderately hard — limescale can build up inside pipes over years and reduce the internal diameter. Jetting removes it.
• Preventative maintenance. If you’ve had a blockage before, or if you run a commercial kitchen or a care home, an annual jetting service keeps the pipes clear and prevents emergencies.

Jetting is NOT the right choice for:

• Collapsed pipes. If the pipe has actually caved in, jetting will just make the problem worse by washing debris into the collapsed section. A CCTV survey first will tell us if the pipe is structurally sound.
• Severe root masses. If roots have been growing inside the pipe for years and have formed a dense mat, jetting alone might not cut through. We use a mechanical root cutter — a rotating blade on a flexible shaft — to clear the big stuff, then jet to clean up.
• Solid objects. If someone has flushed a toy, a cleaning cloth, or a sanitary product, jetting might push it further down the pipe and wedge it in a joint. We use CCTV to locate the object and retrieve it with a grab tool.

That’s why we always start with a CCTV survey before we jet. It tells us exactly what we’re dealing with, so we don’t waste time or make things worse.

The HydraFlow Approach to Drain Jetting in Bexley

When you call us for a blocked drain in Bexley, here’s what happens:

Step 1: Free phone assessment. We’ll ask you a few questions about what’s happening — which drains are affected, how long it’s been going on, whether there’s any smell or visible water. That tells us whether it’s an emergency that needs an immediate callout or something that can wait a few hours.

Step 2: CCTV survey. Before we jet anything, we put a camera down the drain. This is non-negotiable. We need to see the blockage, confirm the pipe is structurally sound, and identify the right tool. The camera footage also gives us a record of the pipe condition, which is useful if the blockage comes back and we need to compare.

Step 3: High-pressure jetting. We use an industrial-grade jetting unit mounted on our van. The hose feeds into the drain through the nearest access point — usually an external manhole or an internal rodding point. The operator controls the pressure and the feed rate based on what the CCTV showed. For roots, we switch to a root-cutting nozzle. For grease, we use a rotating nozzle that scours the full circumference of the pipe.

Step 4: Post-jetting CCTV. After we’ve finished jetting, we run the camera through again to confirm the pipe is clear and to check for any damage or pre-existing issues that need attention. You get to see the before and after footage.

We cover the whole borough — from the riverside properties in Erith and Belvedere, to the suburban streets of Bexleyheath and Welling, to the Kent-border villages of Sidcup, Foots Cray, and Albany Park. We know the local pipework, the common problem spots, and the best access points for each area.

How Much Does Drain Jetting Cost in Bexley?

Drain jetting is surprisingly affordable for what it achieves. Most residential jetting jobs in Bexley cost between £80 and £150, depending on the complexity and the length of pipe that needs clearing. If a CCTV survey is needed first — which we always recommend — that’s usually a separate fee, but it’s money well spent because it means we jet the right thing the first time.

Commercial jetting — for pubs, restaurants, care homes, and schools — costs more because the equipment and the volume of water required are greater, but it’s still far cheaper than digging up a pipe or dealing with a sewage backup that shuts down your business for a day.

We give you the price upfront, before we start any work. No hidden fees, no callout charges that double when you find out it’s a Sunday. If we can’t clear the blockage with jetting — for example, if the pipe has collapsed — we’ll tell you exactly what needs to happen next and what it will cost.

Preventing Blockages After Jetting

Once your drains are jetted clean, you want to keep them that way. A few simple habits make a big difference:

• Bin the fat. Never pour cooking oil or fat down the sink. Let it cool, scrape it into a container, and put it in the general waste. This single habit prevents more blockages than anything else.
• Use drain guards. In Bexley’s older properties, the external gullies — the grates outside your back door or in the driveway — are a common entry point for leaves, silt, and debris. A simple mesh guard over the gully trap stops most of it.
• Flush only the three Ps. Pee, poo, and paper. Wipes, cotton buds, sanitary products, and dental floss do not break down. They snag on every rough joint and every root intrusion, and they’re the starting point for every fatberg.
• Check your manhole covers. Bexley properties nearly all have an external inspection chamber. Lift the cover once every few months and check it’s not full of debris. If it is, clear it out before the next heavy rain washes it into the pipe.
• Consider annual jetting. If you’ve had a blockage before, or if you live in an area with known drainage issues — the Thames-side parts of Erith and Belvedere are particularly prone to silt — an annual jetting service is cheap insurance. It costs less than one emergency callout and prevents the problem from building up again.

Posted by HydraFlow — drainage and plumbing specialists covering London. We provide blocked drain clearance, CCTV drain surveys, high-pressure drain jetting, and emergency drainage services across Bexley and South East London.