What is Drain Cleaning?

Drain cleaning is the process of removing grease, food debris, hair, soap residue, scale and other build-up from the inside of your drainage pipes. Keeping drains clean helps water and waste move through the system properly and can reduce the risk of slow drainage, unpleasant smells and recurring plumbing problems.

The curved trap beneath a sink is designed to hold water and stop sewer gases from entering your home, but it can also collect grease, hair, soap and food debris over time. Regular cleaning helps prevent this residue from developing into a more substantial obstruction.

Drain cleaning is not quite the same as drain unblocking. Drain cleaning focuses on removing build-up and maintaining the condition of your drains, while drain unblocking deals with an obstruction that is already restricting or stopping the flow of water.

Routine drain cleaning can often involve simple preventative maintenance at home, such as clearing visible debris and keeping grease, food waste and hair out of drains. Where build-up is deeper inside the pipework or problems keep returning, a plumber may need to carry out professional drain cleaning using specialist equipment.

What Causes Blocked Drains?

Your drains can become blocked because of everyday waste, gradual build-up or an underlying problem with the pipework itself. Finding the cause matters because clearing the blockage may only give you temporary relief if something inside the system is continuing to trap debris.

Fats/Oils/Grease (FOG)

Fats, oils and grease can go down your sink while they are warm and liquid, then cool and harden further along the pipe. This creates a sticky layer that catches food particles, wipes and other debris.

The problem is widespread. Thames Water has previously reported around three fat-related blockages every hour across London and the Thames Valley. In 2017, a Whitechapel fatberg made from congealed fat, wipes and nappies weighed around 130 tonnes and stretched for 250 metres.

The same thing can happen on a smaller scale inside your own drains, gradually restricting the pipe and contributing to recurring blockages. Let fats, oils and grease cool, then scrape, wipe or pour them into a suitable container for the bin rather than washing them down your sink.

Hair

Hair can easily collect around plugs, strainers and inside your bathroom pipework. As it builds up, it can become tangled with soap residue and other debris and gradually slow the flow of water.

Soap, Shampoo and Product Residue

Every time you use soap, shampoo, conditioner and other bathroom products, some residue can be left behind inside your drains. Over time, it can combine with hair and other debris and make a blockage more likely.

Food Scraps

Small food particles washed down your kitchen sink can become trapped inside the drainage system, particularly where grease or other residue has already collected. Even small amounts can contribute to a larger blockage over time.

Wipes and Personal Hygiene Products

Wipes, sanitary products, cotton products, nappies and similar items do not break down in water like toilet paper does. If you flush them, they can become lodged inside your drainage system and cause serious blockages.

Tree Root Ingress

Tree roots can enter your underground drainage pipes through small cracks, damaged joints or other defects. Once inside, the roots can spread through the pipe and act like a net, catching wipes, grease, food debris and other waste flowing past them.

This is why the same drain can keep blocking even after it has been cleared. If you are dealing with recurring blockages and root ingress is suspected, a CCTV drain survey can help identify the underlying problem rather than repeatedly treating the blockage.

Hair can easily get caught in your drains, especially in the bathroom or shower. As the hair builds up in your pipeline, it may become entwined with other items creating a large, stubborn clog.

Limescale and Mineral Build-Up

If you live in London, your water is naturally hard. Thames Water explains that this is caused by minerals picked up from the local chalk and limestone geology.

Over time, those minerals can form limescale inside your pipes and fixtures, narrowing the space available for water to flow and making it easier for other debris to collect. For your home, this is a normal maintenance issue rather than something you have caused through poor plumbing habits.

Leaves, Silt and Outdoor Debris

Your outside drains and gullies can collect leaves, soil, silt, moss and other debris from the garden, patio or surrounding area. If you allow this material to build up, it can restrict water flow and eventually cause the drain to overflow or block.

Foreign Objects

Toys, clothing, cleaning products and other household items can accidentally find their way into your toilet or drains and become lodged in the pipework. Once stuck, they can catch other waste passing through and create a much larger obstruction.

Damaged or Misaligned Pipework

If your drainage pipes are cracked, collapsed or displaced, waste can become trapped in damaged or uneven sections of pipework. Drain cleaning may clear the immediate blockage, but the problem can return until the underlying damage is identified and repaired.

Poor Drainage Falls or Installation Problems

Your drainage pipes rely on the correct gradient to carry wastewater and solids away effectively. If a pipe has been installed with too little fall, develops a low point or shifts over time, waste can settle instead of moving freely through the system. This can lead to recurring blockages.

Too Much Toilet Paper

Flushing a large amount of toilet paper at once can sometimes block your toilet or drainage pipe, particularly if the system is already partially restricted by scale, roots, damage or other debris.

If the same drain keeps blocking after it has been cleared, it is worth looking beyond the immediate obstruction. Root ingress, damaged pipework or another underlying drainage issue may be causing the problem to return.

How to Keep Your Drains Clean and Prevent Blockages

You cannot prevent every drainage problem, particularly if there is an underlying issue with the pipework, but a few simple habits can reduce the amount of grease, hair, food and other debris entering your drains.

Keep Fats, Oils and Grease Out of Your Drains or Toilet

Do not pour cooking fats, oils or grease down your sink or toilet. Let them cool, then scrape or wipe solid fats into the bin and pour leftover oils into a suitable container for disposal. This helps prevent the sticky build-up that can narrow your pipes and trap other waste.

Use a Strainer in Your Kitchen Sink

A simple sink strainer can catch food scraps before they enter your drainage pipes. Empty it into the bin after washing dishes rather than rinsing the collected debris down the sink.

Catch Hair Before It Goes Down the Drain

Use a hair catcher or drain cover in your shower and bath and clear it regularly. This prevents loose hair from collecting inside the pipework and becoming tangled with soap and product residue.

Only Flush Toilet Paper

Keep wipes, sanitary products, cotton products, nappies and other household waste out of your toilet, even if a product is labelled as flushable. Keep a small bathroom bin nearby so there is an easy alternative.

Clear Visible Debris Regularly

Remove food, hair, leaves and other visible debris from strainers, drain covers and outside gullies before it has a chance to travel further into your drainage system.

Pay Attention to Slow Drainage

If your sink, bath or shower starts draining more slowly than usual, do not ignore it. Slow drainage can be an early sign that build-up is beginning to restrict the pipe. Dealing with the cause early may help you avoid a more stubborn blockage later.

Should You Use Chemical Drain Cleaners?

Chemical drain cleaners are generally not the best first choice for a slow or blocked drain. They may not clear a deeper blockage, and using more product will not fix an underlying problem such as root ingress, damaged pipework or heavy build-up.

More importantly, never mix drain cleaner with bleach or another household cleaning product.

You should also avoid plunging a drain after using a chemical cleaner. If the product is still sitting in the pipework or standing water, plunging can splash the chemical back towards your skin or eyes.

The London Fire Brigade reported that it responded to more than 150 incidents involving dangerous reactions between cleaning chemicals between 2023 and January 2025. In one case, a London resident developed breathing difficulties after using bleach and drain cleaner in the same bathroom.

To use cleaning products safely:

• Read and follow the instructions on the label.
• Never mix different cleaning chemicals.
• Do not use one cleaner immediately after another unless the instructions confirm it is safe.
• Keep products in their original labelled containers.
• If a drain cleaner does not work, consider professional help rather than adding another product.

If you have already used a chemical drain cleaner and need a plumber, tell them exactly what you used before they start work. Residual chemicals may still be sitting inside the pipework, where they could splash onto the plumber or react with other substances when the drain is opened or cleaned. Knowing what has been used helps them choose the safest way to proceed.

DIY Drain Cleaning: How to Clean Drains

You can do a lot to keep your household drains cleaner with simple routine maintenance. The aim is to remove visible debris and light build-up before it has a chance to collect deeper inside the pipework.

If your drain is already fully blocked, repeatedly slow or backing up, routine cleaning may not be enough, and the underlying cause should be investigated.

How to Clean a Sink Drain

To keep your kitchen or bathroom sink drain clean:

1. Remove any visible food, hair or debris from around the plughole.
2. Clean the sink strainer or stopper if you have one.
3. Flush the drain with hot water to help wash away light residue.
4. Clean around the plughole and accessible parts of the waste fitting with a small brush.
5. If your sink has an accessible trap and you are comfortable removing it, place a bucket underneath first and clean out any visible residue before refitting it securely. The trap is one of the areas where food, hair and residue can collect because it holds water and sits at a low point in the waste pipe.

Avoid washing fats, oils, grease or food scraps down the sink afterwards, as these are some of the main causes of build-up.

 

How to Clean a Shower Drain

Hair and soap residue are the main things to watch for in shower drains.

To keep yours clean:

1. Put on gloves and remove any visible hair from around the drain.
2. Lift the drain cover if it is designed to be removed and clear any hair or debris underneath.
3. Clean the cover before replacing it.
4. Rinse the drain with hot water to help remove light soap and product residue.
5. Clean your hair catcher regularly if you use one.

If your shower continues to drain slowly after visible debris has been removed, there may be build-up or a blockage further inside the pipework.

 

Can You Use Baking Soda and Vinegar to Clean a Drain?

Yes, you can use baking soda and vinegar for light routine drain cleaning, but don’t expect the mixture to clear a serious blockage. The fizzing reaction may help loosen some surface residue and can be useful for freshening a drain, but it is unlikely to remove compacted hair, grease, wipes or an obstruction deeper in the pipework.

If your drain is already very slow, completely blocked or keeps developing the same problem, it is better to find the underlying cause rather than repeatedly using home remedies.

Never use baking soda and vinegar in a drain that contains chemical drain cleaner, bleach or another cleaning product. Mixing household cleaning products can cause dangerous chemical reactions.

How to Clean an Outside Drain

Outside drains and gullies need regular attention because leaves, soil, silt and other debris can collect around them.

You can help keep yours clear by:

1. Removing leaves, moss and other visible debris from the grate and surrounding area
2. Clearing any accessible debris sitting inside the gully
3. Checking the drain after heavy rain to make sure water is flowing away normally
4. Keeping nearby soil, garden waste and loose material away from the opening

If an outside drain keeps overflowing or blocking after visible debris has been removed, the problem may be deeper in the system. Root ingress, damaged pipework or another obstruction may need to be investigated.

How Often Should You Clean Your Drains?

You do not need to deep-clean your drains on a strict weekly or monthly schedule. The most useful maintenance is stopping debris from entering them in the first place and removing visible build-up as you notice it.

Empty sink strainers and hair catchers regularly, remove food, hair and other debris from around drain openings, and keep outside gullies clear of leaves and silt. It is also worth paying attention to changes in how quickly water drains.

If the same drain repeatedly becomes slow or needs cleaning, don’t simply clean it more often. Recurring problems can indicate a deeper build-up, blockage or problem with the pipework that needs investigating.

When Is Professional Drain Cleaning Needed?

Routine cleaning can help prevent build-up, but some drainage problems need professional equipment. If your drain keeps blocking, remains slow after visible debris has been removed, backs up or develops persistent smells, there may be a deeper obstruction or an underlying problem with the pipework.

If the problem only affects one sink, bath or shower, it is more likely to be local to that fixture or the nearby pipework. If several drains are affected at the same time, the problem may be further along your drainage system.

For example, if you run a sink and hear the toilet gurgle, or flushing the toilet causes water to bubble or back up in the bath, this can indicate that the problem is not confined to a single drain.

Depending on what is causing the problem, Absolute Plumbing Limited may use one of these drain cleaning methods:

• High-pressure hydro jetting: Uses powerful jets of water to remove stubborn deposits, grease and debris from inside the pipework.
• Rotary machine cleaning: Uses specialist rotating equipment to break up and remove tougher build-up and blockages.

If the cause is unclear or the problem keeps returning, a CCTV drain survey may also be recommended to check for issues such as root ingress or damaged pipework.

Drain Cleaning: Final Thoughts

Regular drain cleaning is largely about stopping grease, food waste, hair, soap residue and other debris from building up inside your pipes. Simple maintenance at home can go a long way, particularly if you deal with visible debris and slowing drainage early.

If the same drainage problem keeps coming back, it is worth getting the cause properly identified rather than repeatedly clearing the symptoms. A professional drain cleaning service can remove deeper build-up and, where necessary, help determine whether root ingress, damaged pipework or another underlying issue is responsible. 

If your drains keep blocking or draining slowly, contact Absolute Plumbing Limited to arrange professional drain cleaning.