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Blocked outside drains are a problem every UK homeowner knows too well. Whether it’s autumn leaves creating havoc, heavy rainfall overwhelming your system, or simple everyday debris building up over time, external drain blockages can quickly turn from minor nuisances into major headaches.

This guide will walk you through everything you need to know about how to unblock a drain outside​. From how to spot early warning signs, understanding what causes blockages, knowing how to unblock drains outside yourself, and knowing when it’s time to call in the professionals.

Read on to equip yourself with handy tips that can keep your outside drains flowing smoothly all year round.

How to Tell If Your Outside Drain Is Blocked

Catching and recognising a blocked outside drain early will save you from wasting time, emergency costs, and a lot of frustration.

But how can you tell something isn’t right with your outside drains before you start searching online for how to unblock drains outside? Here are some telltale signs to look for.

Standing Water

When the blockage is particularly severe or complete, you’ll see standing water even after light rainfall. Water pools around your drain and refuses to flow. You’ll sometimes also see visible debris, and almost always smell an unpleasant odour.

Slow Drainage

In cases where the outside drain isn’t completely blocked, you’ll get slow draining water. This is particularly noticeable during heavy downpours, as outside drains are designed to handle large volumes of water. So any slow drainage is an early indicator that you may need to unblock your outside drain.

Gurgling Sounds

Strange gurgling sounds from your drain is a sign air is being displaced by a blockage somewhere causing odd noises. Any bubbling, gurgling, or sucking sounds could be an early indicator of a blocked drain.

Unpleasant Smells

It isn’t unusual for drains to sometimes have faint unpleasant odours. However, if you notice a persistent odour from your outside drain, don’t ignore it. Any odour is a clear red flag that some type of organic matter is trapped and decomposing in your drainage system.

Visible Debris

If you’re lucky, there’ll be debris clearly visible on or around your drainpipes. Leaves might be blocking the drain hole, mud flowing in from your plants or gardens, or a collection of other debris at the drain opening or just below the surface. Remove this debris and water flow should return to normal.

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What Causes Outside Drains to Become Blocked?

Early telltale signs above could potentially help you catch a blocked outside drain and save you hundreds of pounds or more in emergency fees. To avoid needing to find out how to unblock outside drains, take the pre-emptive step and discover the causes of blocked outside drains.

Autumn Leaves and Garden Debris

During the autumn months, falling leaves are the number one cause of homeowners reaching for outside drain unblockers across the UK. Throw in some twigs, seeds, and other organic matter, and you’ll have all the ingredients for a blockage disaster.

Soil and Sediment

During heavy rainfall, it’s not just water that flows into the drains. Other particles such as soil, sand, and sediments also wash into your drainage system. Over time, these materials build up and restrict water flow.

Grease and Fat

If your kitchen drainage system is connected to the outside drain, wastewater containing oils, fats, and grease can solidify in your outdoor drains, causing a block during colder months. Once solid, it becomes a trap that catches debris and waste flowing down.

Tree Roots

Mature trees near your drainage system can be another cause for needing to unblock a drain outside. As roots naturally seek out water sources and can eventually work their way into drainpipes, they can end up causing blockages and even structural damage over time.

Building Materials

During home improvement or DIY projects, materials like cement, paint, or plaster can accidentally find their way into the drainage system. These materials cannot be easily cleared by external drain unblockers and cause serious blockages that are tough to clear yourself.

Random Objects

It’s uncommon but random small items like children’s toys that get picked up by the wind and end up lodged in drain openings, can also cause obstructions preventing water from flowing.

Hair and Soap Residue

Like kitchen wastewater, bathroom wastewater can cause pipes to become clogged with hair, soap scum, and other personal care products.

Knowing the possible causes of blocked drains will help you decide how to unblock drains outside and which external drain unblockers you need to effectively solve the problem. In some cases, this knowledge can save you time so you can immediately get professional help and not waste time trying DIY methods that can’t solve complex problems.

Preparing to Unblock an Outside Drain

Now that you’re equipped to identify if your outside drain is blocked, we have one final step before we can answer how to unblock an outside drain. Getting prepared.

Here’s what you need to prepare before you try to unblock an outside drain.

Safety Gear

Pulling some sticks or a bunch of leaves out of a gutter can seem easy, but twigs and leaves can sometimes hide thorns or sharp edges that can cut or stab you. Gloves offer vital protection, as does non-slip footwear to reduce the risk of slipping and injuring yourself.

Gather Your Tools

Round up everything you need before starting. You’ll save time having all your equipment ready instead of making multiple trips to look for it.

Check the Weather

For your safety, don’t attempt drain clearance when rain is forecast or during heavy rainfall. Let the rain come to a stop before you even start collecting your tools.

Find the Stopcock

In the unlikely event you hit another pipe or the unblocking process causes a burst pipe, make sure you know the location of your water supply stopcock.

Take Photos

Snap a few pictures of the drain and surrounding area before you start. If the problem turns out to be more than you can handle and you need to call professionals or need proof for insurance purposes, having pictures can be very helpful.

Clear Workspace

Remove any obstacles around the drain opening. Heavy items that can fall on you and hurt you. Sharp objects. Even leaves and other debris can be a hazard. Get rid of them all to make sure you have enough space to work safely and comfortably.

What to Use When Unblocking an Outside Drain

Just as different jobs require different tools, unblocking drains needs the right equipment. What tools do you need when you’re trying to solve the question of how to unblock an outside drain?

Before you set aside time to unblock your outside drain, here’s a list of useful tools for the task ahead.

Basic Tools

Simple items such as rubber gloves, a small trowel or spade, and a bucket can be a great starting point for your outside drain unblocker toolkit.

A plunger that can properly seal the drain opening can make quick work of some blockages. In other situations, a garden hose can deliver a blast of water to clear loose debris and sediment that hasn’t quite set.

If you don’t have any tools or don’t want to spend any money on tools, try wire coat hangers. You can easily straighten one out to fish for debris from shallow drain openings.

Advanced Tools

A drain rod is a line of flexible rods that you can screw together to create a long tool to reach deep into drainage pipes. Most hardware stores sell them, and they work wonders for deeper blockages and are a must-have in your outside drain unblocker toolkit.

Finally, caustic soda and biological drain cleaners are effective options to consider for specific blockages. While they are generally safe, you should always use them with extreme caution and wear proper protective equipment to prevent harm to yourself.

A Step-by-Step Guide to Unblocking an Outside Drain

Now that you’ve collected all the necessary items, checked the weather, and taken pictures, you’re ready to unblock your outside drain. Here’s a systematic approach to tackle your blocked outside drain safely and effectively.

Step 1: Remove the Drain Cover

Carefully lift the cover to expose the drain opening. You should expect some unpleasant smells when you first open it up.

Step 2: Clear Out Visible Debris

If there is any visible debris such as twigs and leaves, use a gloved hand or a small trowel and carefully start removing it. Place it in the bucket and dispose of it appropriately away from your drains.

Step 3: Try Flushing with Water

Once that’s done, or if there is no visible debris, try using your garden hose to flush water down the drain. Start gently then increase the pressure as needed. In some cases, you will successfully solve the problem and can simply replace the drain cover.

Step 4: Use a Plunger

Do this step only if you have a plunger that can create a full seal around your drain hole. If you don’t have it, skip this step.

If water flushing didn’t do the trick, try using a plunger to create a good seal and try to dislodge whatever’s blocking the flow.

Step 5: Get a Drain Rod

For deeper or more severe blockages, you’ll need a drain rod to carefully feed into the drain and try to dislodge the block. Remember to use a clockwise twisting motion to avoid unscrewing the rods as you push them through the pipe.

Step 6: Chemicals

If you’ve tried all the mechanical methods in this How to Unblock an Outside Drain guide and none of them work, your last DIY option is a drain cleaning product. You can get them from hardware stores, but you should always follow manufacturer’s instructions make sure you never use them in closed spaces.

Step 7: Final Test

If you’re successful, do a flush test to see if the water drains. If it does, congratulations you’ve done it! Replace the drain hole cover and check it regularly to ensure it doesn’t block again.

If the water doesn’t drain properly, don’t worry. Replace the drain hole cover to avoid anyone slipping and falling into the drain. Get a professional team to assess and help you permanently clear the block.

When to Call a Professional Drain Unblocker

Thanks to this guide, a useful collection of tools and a bit of DIY elbow grease, you’ve hopefully managed to unblock your outside drain.

However, if things don’t go as planned and you’re wondering if you should try again or call for professional help, here are some situations where you can save time and let the professionals handle it:

Stubborn Blockages

If you’ve tried scooping, pushing, pressure washing, caustic soda, and the block is still there, it’s time to call in professionals. They’ll have access to specialised equipment and techniques that will get it done fast.

Signs of Structural Damage

Stop everything if you notice any cracks in the drain cover, ground subsidence, or signs that the drainpipe itself might be damaged. Immediately get a professional assessment before you accidentally make things worse.

Other Major Problems

If you’re clearing your blockage and notice bio-hazardous material like raw sewage (a very serious health hazard) or tree root problems, or you’re facing a recurrent blockage, seek immediate professional assistance.

Tackling these issues yourself could result in serious health risks or costly damage to your drainage system. Professional drain specialists like our team at Watermains & Drains have access to specialised equipment and can conduct CCTV drain surveys to uncover the real situation in the drains, to quickly and safely resolve your problems.

If you’re looking for comprehensive drain unblocking services, don’t struggle alone. Get experienced professionals to quickly diagnose and resolve even the most stubborn drainage issues.

How to Prevent Blockages in the Future

Prevention beats cure when it comes to outside drain maintenance. Instead of waiting for your drains to become blocked, use these tried-and-tested strategies to keep your external drains clear and flowing freely:

Drain Guards

Using guards or covers over your drain openings will help catch larger debris while still allowing water to flow through freely.

Regular Inspection and Maintenance

Schedule time to check your outside drains regularly, especially during autumn when leaf fall is at its worst. Remove visible debris before it has a chance to build up into a serious problem.

Landscaping

Whenever possible keep trees and shrubs trimmed back from drain areas and avoid planting trees with aggressive root systems close to drainpipes.

Consider Annual Professional Checks

If you live in an older property or have experienced problems before, having your drainage system inspected annually can catch issues before they become major problems.

Keeping your outside drains clear is an essential part of property maintenance regardless of your country. It’s especially important in the UK thanks to our tendency towards heavy rainfall and seasonal debris.

By understanding blockage warning signs and having a clear idea of which tools and techniques work, you can handle simple blockages early to keep your outside drain system working effectively throughout the year.

However, don’t hesitate to call in professional help. While DIY methods can work, it’s safer and often more economical to let professionals like Watermains & Drains solve persistent or complex issues with our decades of experience and specialised equipment.

Struggling with stubborn drain blockages?

Don’t let your drainage problems get worse while you try different solutions. Get in touch with drainage specialists at Watermains & Drains who can provide fast, effective and long-lasting solutions to get your drains flowing freely again