1. Water Drains Slowly — and You’ve Tried the Usual Fixes

This is the most common early warning sign, and it’s also the one people ignore the longest. The kitchen sink takes a few seconds longer to empty than it used to. The shower leaves a puddle around your feet. The toilet gurgles after you flush.

In Richmond, slow drainage is almost never caused by a single blob of grease. The housing stock here is old — we’re talking Georgian, Victorian, and Edwardian properties in areas like Richmond Hill, St Margarets, and East Sheen. The drains are original or near-original: salt-glazed clay pipes with rigid joints, laid over a century ago. Over decades, those pipes have shifted, cracked, and filled with decades of accumulated debris. A slow drain isn’t a sudden problem — it’s the final stage of a process that’s been building up for years.

If you’ve already tried a plunger, a drain snake from B&Q, or a bottle of caustic soda and nothing has worked, stop. Those products only clear the surface of the blockage. The real problem is deeper in the pipe, and you need a CCTV survey to find it. A drain engineer will put a camera down the pipe, identify exactly what’s causing the restriction, and clear it properly with high-pressure jetting or a mechanical cutter. No guesswork, no chemicals, no temporary fixes.

2. There’s a Bad Smell Coming From Your Drains

A foul smell from your drains — and we’re talking the kind of smell that makes you open all the windows — is a sign that something is rotting inside the pipe. It could be food waste that’s been sitting in a grease layer for weeks. It could be stagnant water that can’t drain because of a partial blockage. Or it could be something worse: a broken pipe that’s letting sewage seep into the soil under your property.

Richmond’s older properties are particularly prone to this because of the way the drainage systems were built. Many Victorian and Edwardian houses have combined drainage — one pipe carries both rainwater and wastewater. That means when there’s a heavy downpour — and Richmond gets plenty, being in the Thames valley — the extra volume of water can disturb the sediment in the bottom of the pipe and release trapped gases. If the pipe is already partially blocked, the smell gets forced back up through the nearest open drain.

There’s also the issue of dry traps. In warmer weather, the water in an unused gully trap or floor drain can evaporate, allowing sewer gases to come straight up into your house. That’s an easy fix — pour a bucket of water down the drain to reseal the trap. But if the smell persists after that, you’ve got a blockage or a break somewhere in the system, and you need an engineer to find it.

3. You Can Hear Gurgling or Bubbling From Your Pipes

If your toilet bubbles when you run the bath, or your kitchen sink gurgles when the washing machine empties, you’ve got an airlock problem. And an airlock problem is almost always caused by a partial blockage further down the pipe.

Here’s what’s happening: the pipe is partially blocked, so when water from one appliance tries to drain, it can’t push past the blockage fast enough. The displaced air has to go somewhere, so it bubbles up through the nearest open drain — usually the toilet or the sink. It sounds like someone blowing bubbles through a straw, and it’s a dead giveaway that there’s a restriction in the main drain.

In Richmond, this is especially common in the terraced houses around the town centre and in St Margarets, where multiple properties often share a single lateral drain running to the main sewer. If your neighbour’s blockage is causing your toilet to gurgle, you’re sharing the same problem. Thames Water is responsible for shared drains, but they won’t come out for a partial blockage — they only act when the drain is completely blocked and causing a flood. A private drain engineer can clear the partial blockage before it becomes a full-blown emergency, and you don’t have to wait for the council or the water company to get around to it.

4. There Are Damp Patches or Sinking Ground in Your Garden

This is the one that people miss most often, because it doesn’t involve a toilet or a sink. You notice a patch of your lawn that’s always a bit wet, even when it hasn’t rained. Or a section of your patio that’s started to sink. Or a strange lush patch of grass that’s greener than everything else in the garden.

That’s a leaking drain pipe. The pipe has cracked or the joint has failed, and wastewater is seeping into the ground. The grass loves the extra nutrients — that’s why the patch looks so green. But the water is also washing away the soil underneath, creating a void. Over time, that void gets bigger, and the ground above it sinks. If the leak is under your patio or your driveway, you’ll notice the paving slabs starting to tilt or crack. If it’s under your lawn, you’ll see a depression that gets a bit deeper every month.

Richmond’s soil is mostly London Clay, which is great for gardens but terrible for drainage pipes. Clay shrinks in dry weather and expands when it gets wet, and that movement puts stress on every joint in the pipe. The older the pipe, the more likely it is to fail. The properties on Richmond Hill, with their steep gardens running down towards the river, are particularly vulnerable — the ground movement is more pronounced on a slope, and a leak on a slope can quickly turn into a subsidence issue that affects the foundations of your house.

If you see a damp patch that doesn’t dry out, or if you notice your garden sinking, call an engineer. A CCTV survey will locate the leak, and the fix — usually a patch lining or a section replacement — is much cheaper than repairing a collapsed garden wall or a subsiding foundation.

5. You’ve Got Tree Roots Near Your Drainage Pipework

Richmond is one of the greenest boroughs in London. Richmond Park alone has over 2,500 acres of ancient woodland and grassland. The streets are lined with mature plane trees, oaks, and horse chestnuts. The gardens are full of established shrubs and trees. It’s beautiful — and it’s a nightmare for your drains.

Tree roots are drawn to drains like a magnet. A clay drain pipe with a slightly loose joint emits warmth, moisture, and nutrients. A root tip finds that joint, pushes through, and starts growing inside the pipe. Once it’s in, it expands. A single root the thickness of your finger can completely block a 100mm drain pipe within a few growing seasons.

The first sign is usually slow drainage in the summer — when the tree is actively growing and drawing moisture. The second sign is recurring blockages that keep coming back no matter how many times you clear them. The third sign is a complete blockage that happens suddenly after a storm, when the wind rocks the tree and the roots shift inside the pipe.

If you’ve got mature trees within five metres of your drain line — and in Richmond, that’s most properties — you need to be proactive. A CCTV survey every couple of years will catch root ingress early, when it can be cleared with a root-cutting jetting nozzle. Leave it too long and the roots will be thick enough to crack the pipe, and you’ll need a full excavation and replacement.

HydraFlow’s engineers carry root-cutting attachments for our jetting rigs. We can clear roots up to about 25mm diameter without digging. For thicker roots, we use a mechanical cutter — a rotating blade on a flexible shaft — to cut through the mass, then jet the pipe clean. We always follow up with a post-clearing CCTV survey to make sure the pipe is intact and the roots haven’t caused structural damage.

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 Richmond and South West London.