Blocked Drains in Alton - Common Causes and Fixes Every Homeowner Should Know

Published October 2026 | Blocked Drains

You notice water pooling around the shower tray on a Monday morning, and by the time you've finished getting ready, it still hasn't drained. Later that day the kitchen sink starts gurgling every time you run the dishwasher. It's the kind of thing you hope will sort itself out - but with drains, it almost never does.

Understanding What's Actually Happening in Your Drains

A blocked drain is, at its core, a restriction in your waste or drainage system that stops water flowing freely toward the sewer. That restriction can be anything from a soft grease build-up to a partially collapsed pipe, and the location of the blockage determines both how serious it is and what needs to happen to clear it.

In Alton, a significant proportion of residential properties are older builds - Victorian terraces, post-war semis, rural conversions - and the underground drainage in these homes has often never been properly inspected. When something does go wrong, the underlying cause has sometimes been developing quietly for years before any visible symptom appears.

There are two broad categories to understand. Internal blockages sit above ground, inside your property, in the waste pipes connected to your sinks, baths, showers, and toilets. These are generally the easier ones to deal with. External blockages live in the underground drainage runs that carry waste from your property to the public sewer, and these are where things get more involved - and more expensive.

The Most Common Causes of Blocked Drains

Most blockages don't appear overnight. They build up gradually until something tips the balance and flow stops almost completely. Here are the causes our engineers see most regularly.

Fat, Oil, and Grease

This is the single most frequent cause of blocked kitchen drains. When you pour cooking fat, oil, or grease down the sink, it flows easily in its warm liquid state - but as it cools in the pipe, it solidifies and sticks to the inner walls. Over time, other particles of food and debris bond to it, and what starts as a thin coating gradually narrows the pipe bore until flow slows to a trickle and eventually stops. Fat, oil, and grease are among the most well-documented causes of household drain blockages in the UK.

The fix sounds obvious in retrospect: never pour fat down the sink. Let it cool in a container and bin it. But once you already have a grease blockage, you'll need to actively clear it - more on that shortly.

Hair and Soap Scum

Bathroom drains take a battering from two sources that work together to create stubborn blockages: hair and soap scum. Hair binds into clumps that catch on any rough edge inside the pipe. Soap scum - the residue left by soap reacting with minerals in hard water - coats the inside of waste pipes and gives hair and debris something to stick to. In combination, they form dense mats that are surprisingly difficult to shift with hot water alone.

Shower traps are particularly prone to this, and in our experience, it's one of the most common reasons Alton households call us out. The good news is that most hair blockages sit close to the surface, inside or just below the visible drain cover, which makes them accessible without specialist equipment.

Wet Wipes and Non-Flushable Items

Despite being labelled as "flushable" in some cases, wet wipes don't break down in water the way toilet paper does. They accumulate in bends and junctions in the drainage system, catching other debris as it passes until a mass forms that water can't get through. Drainage specialists consistently identify wipes as one of the top causes of serious blockages in residential drainage systems. Cotton buds, sanitary products, and nappy liners cause the same problem.

This type of blockage often sits further down the drainage run than a hair or grease block, which is why it can take longer to notice and why it tends to be more disruptive when it finally makes itself known.

Tree Root Ingress

Tree roots are drawn to the moisture and nutrients inside underground drain pipes. In older clay or pitch-fibre drainage - common in Hampshire properties built before the 1980s - roots can infiltrate through joints and cracks that have opened up over decades of ground movement. Once inside, they grow into the pipe bore and catch everything that passes, creating a blockage that clears temporarily with jetting but returns again and again unless the root entry point is repaired.

If you're in an Alton property with mature trees in the garden or on the road nearby, root ingress is worth considering any time you have a recurring external blockage. A CCTV survey is the only reliable way to confirm it.

Scale and Mineral Deposits

Parts of Hampshire sit in areas with moderately hard water, and while limescale is more commonly associated with boilers and appliances, it does accumulate inside waste pipes over time - particularly where there's also soap residue or grease providing something for it to bond to. Scale build-up narrows the pipe bore gradually, reducing flow and increasing the risk of blockage whenever anything else enters the system.

Collapsed or Misaligned Pipes

Older drainage systems can develop physical defects: pipes that have cracked under ground pressure, joints that have shifted apart, or sections that have dropped slightly out of alignment and now hold standing water and silt. Drainage specialists in the Hampshire area note that repeat blockages often point to root ingress, collapsed pipes, scale, poor falls, or damaged chambers rather than a simple one-off obstruction. These structural problems can't be resolved with rods or jetting alone - they need to be identified and repaired at source.

Solutions That Actually Work

The right approach depends on where the blockage is and what's causing it. Here's how to think through the options.

For slow-draining sinks and shower traps:

1. Remove and clean the trap or drain cover. With a shower, the hair mat is often visible immediately below the cover and can be lifted out by hand.
2. Use a drain plunger to create suction and dislodge any soft obstruction further down the pipe.
3. Try a proprietary drain cleaner - caustic products for grease-based blockages, or enzymatic cleaners for general build-up - and follow the instructions carefully. Don't mix products.
4. If none of that works, a handheld drain auger (also called a drain snake) can reach further into the pipe and physically break up or retrieve the blockage.

For toilets:

1. Use a toilet plunger - not a standard cup plunger. Make sure there's enough water in the bowl to cover the plunger head before you start working it.
2. If plunging doesn't resolve it after a few attempts, an auger designed for toilet use can help. Avoid chemical unblockers in toilets - they're rarely effective and can damage the seals and pan over time.
3. If you still can't identify or clear the blockage, this is the point to call an engineer rather than persist.

For external drain blockages:

1. Locate your inspection chambers (manhole covers in the garden or driveway). If one is flooded and the next one downstream is clear, the blockage sits in the section of pipe between them.
2. Drain rods can be used to push through soft blockages in external runs, but you need some confidence with the tool - it's easy to unscrew a rod section accidentally and lose it in the pipe.
3. High-pressure water jetting, carried out by a professional, is more effective than rodding for most external blockages and cleans the pipe wall at the same time.

When You Need Professional Help vs Sorting It Yourself

An internal blockage you can reach and clear without specialist tools is a reasonable DIY job. But there are clear signals that tell you when to stop and call someone in.

Call an engineer if:

• Multiple fixtures are draining slowly or backing up at the same time - this typically points to a blockage in a shared drain run rather than an individual waste pipe.
• The problem keeps coming back within a few weeks of clearing it. Repeat blockages nearly always indicate an underlying structural issue.
• You can see or smell sewage backing up into a ground-floor fixture or outside in the garden.
• Drain rods won't pass through the pipe - this suggests a partial collapse or root mass that needs jetting and CCTV investigation.
• You're not sure where the blockage is, or whether your drains are your sole responsibility or shared with neighbouring properties.

Our engineers use the Voltrade GoFIX diagnostic tool during the initial assessment to log observations and help identify whether a blockage has a simple cause or points to a deeper structural problem - which avoids unnecessary repeat visits and gets you a clearer picture of what you're actually dealing with.

What to Expect from a Repair Visit

If you call out a professional drain engineer to an Alton property, here's typically what happens from start to finish.

The engineer will start by asking where you've noticed the symptoms and whether the problem is isolated to one fixture or affecting multiple outlets across the property. They'll locate the inspection chambers and check water levels to pinpoint the section of drainage where the blockage is sitting.

For an accessible blockage, high-pressure water jetting is usually the first approach - it clears the obstruction and cleans the pipe wall in a single pass. This commonly takes between 30 minutes and an hour for a standard residential drain run.

If the cause isn't immediately obvious or the blockage has been recurring, a CCTV drain survey is the next step. A camera is fed through the pipe and the engineer can see exactly what's happening - root ingress, cracks, misaligned joints, or silt accumulation. You'll typically receive a written report with footage you can keep for your records.

Typical costs in the Alton area:

• Basic drain unblocking (jetting or rodding): typically between 80 and 150 pounds for a standard visit
• CCTV drain survey: typically between 150 and 300 pounds, depending on the length of pipe surveyed
• Drain lining or pipe repair following a survey: patch lining commonly runs from 300 to 800 pounds; full section replacement varies considerably and can be significantly more depending on depth and access

Always ask for a fixed quote before work starts, and confirm with the engineer whether any underground drainage work will require Building Regulations notification - for certain drainage alterations, it does.

Common Questions from Alton Homeowners

Is a blocked drain in my garden my responsibility or the water company's?

Generally, drains within your property boundary that only serve your home are your responsibility to maintain and repair. Once a drain becomes a shared sewer - carrying waste from more than one property - it's typically the water company's responsibility. In Hampshire, Southern Water manages the public sewer network. If you're unsure where the boundary falls, a drainage engineer can check the public sewer map and advise you before any work begins.

Can I use chemical drain cleaners regularly to prevent blockages?

Caustic drain cleaners can help shift an existing grease or hair blockage, but regular use isn't a substitute for good habits and isn't advisable for older pipework. Enzymatic cleaners are gentler and can be used more regularly as a light preventative measure in kitchen drains. The most effective long-term approach is simply keeping the wrong things out of your drains in the first place - particularly cooking fat and wet wipes.

How do I know if tree roots are causing my drain blockage?

The clearest sign is a blockage that clears with jetting but returns within a few weeks, consistently in the same section of drain. You might also notice a persistent gurgling from toilets or slow drainage affecting multiple outlets simultaneously. The only reliable way to confirm root ingress is a CCTV survey - an engineer feeds a camera through the pipe and can see exactly where roots have entered and how severely they're affecting flow through the pipe.

How long does a drain unblocking visit typically take in Alton?

Most standard drain unblocking visits take between one and two hours from arrival to completion, depending on the location and nature of the blockage. Simple internal blockages are sometimes resolved in under an hour. External blockages that need jetting and a bit of investigation typically take longer. If a CCTV survey is needed on the same visit, allow two to three hours in total so the engineer can do the job properly.