So, you have come home to a foul stench and discovered that your drains are blocked. Don’t worry, don’t panic, hold your nose and read on. Blocked drains are a common occurrence and although you may need a plumber if it is particularly bad, you may be able to clear the problem yourself. In this article, we’ll provide a brief overview of the steps involved in unblocking an outside drain, so you can take action quickly and effectively if needed.

How Do Outside Drains Get Blocked?

Outside drains can become blocked for a variety of reasons. Some of the most common causes of outside drain blockages include:

  1. Debris: Leaves, twigs, and other organic matter can accumulate in the drain, causing a blockage over time.
  2. Grease and Fat: Grease and fat from cooking can solidify in the drain, causing a blockage.
  3. Roots: Tree roots can grow into the drain and cause a blockage.
  4. Foreign Objects: Items such as toys, balls, and other objects can accidentally be flushed down the drain, causing a blockage.
  5. Soil and Dirt: During heavy rainfall, soil and dirt can be washed into the drain, causing a blockage.

What You Need to Unblock an Outside Drain

When it comes to unblocking an outside drain, having the right tools and materials can make all the difference. Here are the key items you’ll need to unblock an outside drain:

Drain Rods

Drain rods (Amazon link – opens in a new tab) are long, flexible rods that can be screwed together to create a longer length. They are used to physically push or break up blockages within the drain.

Rubber Gloves

It’s important to wear gloves to protect your hands from bacteria and potential hazards when working with the drain.


You’ll need a bucket to collect any debris that comes out of the drain during the unblocking process.

Hose or Pressure Washer

A hose or pressure washer can be used to flush the drain and remove any remaining debris.

Drain Unblocker Chemicals (Optional)

Drain unblocker chemicals can help to dissolve and break up stubborn blockages. However, these chemicals should be used with caution, as they can be harmful to the environment and may damage the drain if not used correctly.

Steps for Unblocking an Outside Drain

When an outside drain becomes blocked, it’s important to take action as soon as possible to prevent further damage. Here are the steps you can follow to unblock an outside drain:

1 – Protect Yourself

Put on rubber gloves to protect your hands from bacteria and debris.

2 – Remove Easy to Reach Debris

Remove any visible debris or blockages from the drain using your hands or a trowel. Collect any debris that comes out of the drain in a bucket and dispose of it appropriately.

3 – Use Drain Rods

Use drain rods to physically push or break up the blockage. Insert the rods into the drain and twist them in a clockwise direction to dislodge the blockage. Continue doing this until the blockage is removed or loosened.

Drain Rods
Drain Rods

4 – Flush with Water

Once the blockage has been loosened, flush the drain with water from a hose or pressure washer to remove any remaining debris.

5 – Try a Chemical Solution

If the blockage is particularly stubborn, you may want to try using drain unblocker chemicals. Follow the instructions carefully and use the chemicals with caution, as they can be harmful to the environment and may damage the drain if not used correctly.

6 – Rinse

Once the drain is unblocked, rinse it thoroughly with water to ensure that it is flowing freely.

Important: It’s important to take safety precautions throughout the unblocking process. Be careful not to damage the drain with excessive force and avoid using chemical unblockers unless absolutely necessary.

What to Do if You Cannot Clear the Blockage?

If you’re unable to remove the blockage yourself or if the blockage is particularly stubborn, it’s best to seek professional help. Here are some options to consider:

Call a Drainage Company

A drainage company will have the expertise and equipment to unblock even the most stubborn blockages. They will typically charge a fee for their services, but it can be worth the cost to avoid further damage to the drain.

Contact Your Local Council

Depending on the location of the blocked drain, your local council may be responsible for its maintenance and unblocking. Contact your local council to find out if they provide this service and what the procedure is for requesting assistance.

Seek Assistance from Your Water Company

Some water companies offer a service for unblocking outside drains. Contact your water company to find out if they offer this service and what the procedure is for requesting assistance.

Note: If the blockage has caused flooding or is posing an immediate risk to health and safety, it’s important to seek assistance as soon as possible. In these cases, you may want to contact the emergency services or your local authority for advice on how to proceed.

How to Stop Outside Drains Getting Blocked?

Preventing outside drain blockages is much easier than dealing with them once they have already occurred. Here are some key steps you can take to prevent outside drain blockages:

Regular Maintenance

Regularly inspect your outside drains and remove any visible debris or blockages before they can cause a problem.

Dispose of Waste Properly

Avoid flushing items such as cooking fat, oil, or food scraps down the drain. These can solidify and cause a blockage.

Install Drain Covers

Installing a drain cover can help to prevent debris and other objects from entering the drain.

Trim Trees and Shrubs

Tree roots can grow into the drain and cause a blockage. Keep trees and shrubs trimmed back from the drain to prevent this from happening.

Consider a Professional Inspection

If you’re experiencing recurring blockages or are unsure about the condition of your outside drains, consider hiring a professional to inspect them. They can identify any potential issues and provide advice on how to prevent blockages in the future.


Unblocking an outside drain may seem like a daunting task, but with the right tools and knowledge, it can be a relatively straightforward process. By following the steps outlined in this article, you can effectively remove blockages and prevent further damage to your drain.

However, prevention is key when it comes to outside drain blockages. By taking simple steps such as regular maintenance, proper waste disposal, and installing drain covers, you can prevent blockages from occurring in the first place.

If you’re unable to remove a blockage yourself, seek professional help to avoid causing further damage to the drain or surrounding area.

Remember, maintaining your outside drains is not only important for your own property but also for the wider environment and community. By taking preventative measures and dealing with blockages promptly, you can help protect your local area from flooding and ensure that your outside drains function properly for years to come.

How to Unblock an Outside Drain Infographic

Plumbing Wizard Tips

“Regular inspection can help to identify any blockages or debris in the drain before they cause a problem. Use a torch or a camera to inspect the drain and remove any visible debris!”

“Avoid flushing items such as cooking fat, oil, or food scraps down the drain. These can solidify and cause a blockage!”

“If you’re unable to remove a blockage yourself or if the blockage is particularly stubborn, seek professional help. Drainage companies, local councils, and water companies may offer unblocking services!”

“A mixture of boiling water and baking soda can help to break down small blockages and prevent future blockages from occurring. Simply pour the mixture down the drain and wait for a few minutes before flushing with water!”

Frequently Asked Questions

What is the best outside drain unblocker?

The best outside drain unblocker depends on the type and severity of the blockage. Some effective unblockers include chemical drain cleaners, baking soda and vinegar, hot water, and professional drain unblocking services.

Why does my outside drain keep blocking?

Outside drains can keep blocking due to a variety of factors including leaves, dirt, debris, oil and fat deposits, tree roots, and foreign objects such as toys or garden equipment. It’s important to regularly inspect and maintain your drains to prevent recurring blockages.

Should there be standing water in an outside drain?

No, there should not be standing water in an outside drain. If you notice standing water, it may indicate a blockage or a problem with the drainage system.

Will caustic soda unblock an outside drain?

Caustic soda can be effective for unblocking outside drains, but it should be used with caution as it can be hazardous to handle and can damage some types of pipes.

How do you unclog a drain instantly?

The quickest way to remove a blockage in a drain is to use drain rods or an auger. The force of the rod should dislodge or break apart the blockage allowing the water to flow freely again.

What liquid do plumbers use to unclog drains?

Plumbers may use a variety of liquids to unclog drains, including chemical drain cleaners, enzymes, vinegar and baking soda mixtures. The best solution depends on the type and severity of the blockage.

Can you use drain unblocker on outdoor drains?

Yes, drain unblockers can be used on outdoor drains. Ensure the product is appropriate for the type of blockage and material of your drain.

Will bleach unblock an outside drain?

While bleach can break down certain organic materials causing a blockage, it’s not always effective for severe blockages and can be harmful to the environment.

How do you unclog an outdoor underground drain?

You can use a plumber’s snake or a high-pressure water jetting system. For significant blockages or root intrusions, you might need professional assistance.

Does Mr Muscle work on outside drains?

Mr Muscle is designed primarily for indoor drains, but it might help with minor outdoor blockages. However, for significant blockages, specialised products or mechanical methods might be more effective.

Does washing up liquid unblock drains?

Washing up liquid can help break down greasy build-ups, but it’s not a primary solution for severe blockages. It can be used as a preventative measure or for minor blockages.

How do you unblock a badly blocked drain?

For severe blockages, mechanical methods like a plumber’s snake or high-pressure water jetting are often effective. In persistent cases, you might need to call a professional plumber.

Why you should never use baking soda and vinegar to unclog a drain?

While the reaction between baking soda and vinegar can dislodge minor blockages, it’s not effective for significant obstructions. Furthermore, the combination creates water and salt, which can eventually contribute to pipe corrosion.

Does bicarbonate of soda unblock drains?

Bicarbonate of soda (baking soda) can help with minor blockages, especially when combined with vinegar. However, for tougher blockages, other methods or products are recommended.

How do you clear a slow outside drain?

Start by physically removing visible obstructions like leaves or debris. If the drain remains slow, try a drain cleaning product, a plumber’s snake, or a high-pressure water jet.

Where does water from outside drains go?

Water from outside drains usually goes to the stormwater system, which typically leads to local waterways or soakaways, depending on local infrastructure and regulations.

Where does outdoor drain water go?

Outdoor drain water, specifically from stormwater drains, usually flows into local waterways, and stormwater ponds, or is absorbed into the ground through soakaways. It’s separate from the sewage system to prevent overflows and contamination.


Lee Pearce is not just a master plumber; he’s a veritable Plumbing Wizard. With over 30 years of experience in the trenches of pipes and drains, Lee has become the go-to sage for DIY plumbing, saving homeowners thousands in potential call-out charges. As the founder of Plumbing Wizard, he’s dedicated to demystifying the complexities of home plumbing, offering easy-to-follow advice that stands the test of time and pressure. His online blog is a treasure trove of tips, tricks, and tutorials that empower everyday individuals to take charge of their home’s plumbing health. Lee’s practical wisdom is not just about fixing leaks; it’s about imparting confidence and self-reliance. When he’s not writing or elbow-deep in a plumbing project, Lee is passionate about educating the next generation of DIYers, ensuring that practical skills are passed down and preserved.

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