Blocked outside drains can turn a minor inconvenience into a major headache. Whether it’s causing unpleasant odours, creating unsightly pools of water, or even leading to more severe plumbing issues, an outside drain blockage needs to be addressed promptly. At PM247, we understand the frustration and potential damage that a blocked drain can cause, which is why we’ve put together this comprehensive guide to help you unblock your outside drain effectively. With these tips and methods, you can tackle the problem yourself or know when it’s time to call in the professionals.

In most cases, you may not need a drainage engineer and there are various ways you can effectively (and swiftly) deal with a blocked drain. Read on to discover what to do when your drain is blocked so you can get the better of this pesky plumbing issue.


how to unblock a drain outside

Identifying the Source of the Blockage

Before you can unblock an outside drain, you need to identify the source of the blockage. This step is crucial as it determines the method you’ll use to clear the drain.


Signs of a Blocked Outside Drain

  • Multiple Slow Drains: If multiple drains in your house are slow or not draining, the issue is likely with your outside drain.
  • Gurgling Sounds: Unusual gurgling sounds from your drains can indicate a blockage in the outside drain.
  • Water Pooling Outside: Visible water pooling around your drain cover is a clear sign of an outside blockage.
  • Foul Odours: Unpleasant smells around your property can suggest a blockage in the outside drain.

Locating the Blockage

Once you’ve identified the symptoms, the next step is locating the blockage. Outside drain blockages are often caused by:

  • Leaves and Debris: Natural debris like leaves and dirt can accumulate over time.
  • Fat, Oil, and Grease (FOG): Cooking residues can solidify and cause blockages.
  • Roots: Tree roots can infiltrate and obstruct drains.
  • Foreign Objects: Items like plastic bags or toys can accidentally end up in drains.

Take note, if the problem is in your lateral drain, this should be handled by your water company.


Methods to Unblock an Outside Drain

Remove Surface Debris

The first step in tackling an outside drain blockage is to clear any visible debris around the drain cover.

  1. Safety First: Wear gloves and protective clothing to avoid contact with potentially harmful substances.
  2. Clear the Area: Remove leaves, dirt, and any other debris from around the drain cover.
  3. Lift the Drain Cover: Use a suitable tool to lift the drain cover and inspect the inside of the drain for visible blockages.

Hot Water Method

Pouring boiling water down the drain is one of the simplest and most effective methods for dissolving blockages caused by fat and grease.

  1. Boil Water: Boil a large kettle or pot of water.
  2. Pour Carefully: Slowly pour the boiling water into the drain, taking care not to splash yourself.
  3. Repeat if Necessary: For stubborn blockages, you may need to repeat this process several times.

Bicarb and Vinegar Method

Using bicarbonate of soda (baking soda) and vinegar can create a fizzy reaction that helps to dislodge blockages.

  1. Pour Bicarb: Pour half a cup of baking soda into the drain.
  2. Add Vinegar: Follow with a cup of vinegar and quickly plug the drain to contain the fizzing reaction.
  3. Let It Sit: Allow the mixture to sit and fizz for about 30 minutes.
  4. Rinse with Hot Water: After the fizzing stops, pour hot water down the drain to help clear any remaining debris.

Using a Plumbing Snake

A plumbing snake, also known as a drain auger, is a flexible, long metal cable used to break up blockages deep within the drain.

  1. Insert the Snake: Feed the plumbing snake into the drain until you encounter resistance.
  2. Rotate the Snake: Turn the handle to break up the blockage.
  3. Retrieve the Snake: Pull the snake out, bringing any debris with it.
  4. Repeat if Necessary: You may need to repeat this process until the drain is clear.

Wet and Dry Vacuum

A wet and dry vacuum can create strong suction to remove blockages.

  1. Seal the Drain: Create a tight seal between the vacuum nozzle and the drain opening.
  2. Set to Vacuum: Set your vacuum to “wet” mode if applicable.
  3. Suck Out the Blockage: Turn on the vacuum to suck out the blockage. This may require multiple attempts.

Biological Drain Cleaners

Biological cleaners use enzymes to break down organic material without damaging your pipes or the environment.

  1. Choose a Product: Select a biological drain cleaner from your local hardware store.
  2. Follow Instructions: Apply the cleaner according to the manufacturer’s instructions.
  3. Allow Time: Give the cleaner time to work, usually a few hours or overnight.
  4. Rinse the Drain: Flush the drain with hot water after the cleaner has had time to work.

Call us on 0808 250 4203 or fill in the form here to get your blocked drain fixed by a skilled PM247 plumber (UK wide service). 


Additional Tips for Unblocking Outside Drains

High-Pressure Hose

Using a high-pressure hose can be an effective way to blast away stubborn blockages. Attach the hose to a high-pressure nozzle and direct it into the drain, working it back and forth to dislodge the debris.

Drain Rods

Drain rods are a series of flexible rods that can be screwed together to form a longer tool. They are ideal for reaching deep blockages and can be rotated to help break up and push the blockage through the drain.

  1. Assemble the Rods: Connect the rods together to the required length.
  2. Insert into the Drain: Push the rods into the drain until you reach the blockage.
  3. Rotate and Push: Rotate the rods to break up the blockage and push it through the drain.
  4. Withdraw and Clean: Remove the rods and clean them thoroughly after use.

CCTV Drain Survey

If the blockage is persistent and you can’t determine the cause, a CCTV drain survey can be helpful. This involves inserting a small camera into the drain to visually inspect the interior and identify the blockage’s exact location and nature. You are unlikely to have these at home, but call PM247 for a survey.

Enzyme-Based Cleaners

Enzyme-based cleaners are a gentler alternative to harsh chemicals. These cleaners use natural enzymes to break down organic matter and can be used regularly to maintain your drains and prevent blockages.

Preventative Measures

Taking preventative measures can save you time and effort in the long run.

  • Install Gully Guards: Gully guards can prevent leaves and debris from entering the drain.
  • Regular Cleaning: Regularly clean your drains and remove any debris to prevent build-up.
  • Use Strainers: Place strainers in your sinks to catch food particles and other debris before they enter the drain.

Call us on 0808 250 4203 or fill in the form here to get your drain surveyed or jetted by a skilled PM247 plumber (UK wide service). 


Preventing Future Blockages

Preventing blockages is often easier and less stressful than dealing with them. Here are some tips to keep your outside drain clear and free-flowing:

Regular Maintenance

Regular maintenance can help prevent blockages from occurring in the first place.

  • Clean Regularly: Periodically remove leaves and debris from around your outside drains.
  • Inspect Drains: Regularly inspect your drains for signs of blockages or slow drainage.
  • Use Drain Covers: Install drain covers to prevent debris from entering the drain.

Proper Disposal of Waste

Proper disposal of waste can significantly reduce the risk of blockages.

  • Dispose of FOG Properly: Never pour fat, oil, or grease down your drains. Instead, collect it in a container and dispose of it in the trash.
  • Avoid Flushing Foreign Objects: Do not flush items like wipes, sanitary products, or other non-biodegradable items down the toilet or drain.

Tree Root Management

Tree roots can cause significant damage to your drainage system if left unchecked.

  • Plant Wisely: Plant trees away from your drainage system to avoid root infiltration.
  • Regular Inspections: Have a professional inspect your drainage system for root intrusion regularly.
  • Root Barriers: Consider installing root barriers to prevent roots from reaching your drains.


Done Trying to Unblock Your Outside Drain?

Dealing with a blocked outside drain can be a daunting task, but with the right knowledge and tools, you can often resolve the issue yourself. By following the methods outlined in this guide, you can tackle most blockages effectively. However, if you find the blockage persists or is beyond your capabilities, the experts at PM247 are here to help. Our commitment to quality service and customer satisfaction ensures that your drainage problems are resolved swiftly and professionally. Don’t let a blocked drain disrupt your life—contact PM247 today for reliable, expert assistance.


When to Call a Professional

Despite your best efforts, some blockages require professional intervention. Here’s when you should call in the experts at PM247:

  • Persistent Blockages: If the blockage does not clear after using the above methods, it’s time to call a professional.
  • Severe Blockages: Large or severe blockages, such as those caused by tree roots, often require specialised equipment and expertise.
  • Recurrent Issues: If your drains frequently become blocked, a professional inspection can identify underlying issues and provide long-term solutions.
  • Emergency Situations: For urgent problems causing significant disruption or potential damage, professional help is essential.


How PM247 Can Help

At PM247, we offer a comprehensive range of plumbing services to address any drainage issue you may encounter. Here’s what sets us apart:

1. 24/7 Emergency Services

We understand that plumbing emergencies can happen at any time. Our 24/7 emergency service ensures that help is always just a phone call away.

2. Expert Plumbers

Our team of skilled plumbers has the experience and tools necessary to handle even the most challenging blockages. We pride ourselves on delivering efficient, high-quality service to get your drains flowing smoothly again.

3. Competitive Pricing

We offer competitive pricing for all our services. Small jobs come with a low, set price, so you know exactly what to expect.

4. Comprehensive Solutions

From minor blockages to major drainage issues, we provide comprehensive solutions tailored to your specific needs. Our goal is to ensure your drains remain clear and functional long-term.

Contact Us

If you’re facing a blocked outside drain, don’t hesitate to reach out to us at PM247. Our knowledgeable team is ready to assist you and restore your drainage system to optimal condition.


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