How to Professionally Unblock a Drain Outside

Rain Flowing Into A Storm Water Sewer System

A blocked outside drain can be a nightmare, in extreme cases spilling water into your garden and creating foul odours. If your property is unable to drain rainwater it can also cause damage, including house flooding. 

In this handy guide from Coastal Drains, we’ll cover the telltale signs that your outside drain is blocked, and explain how to unblock an outside drain. There are a variety of methods to unblock an external drain, including manual removal, caustic soda, using a garden hose, and drain rodding.

What Causes Blockages in an Outside Drain?

Gutter Maintenance A Man Is Removing Leaves from a Blocked Rain Gutter

A blockage in a drain outside your house could be caused by several things. While it is more common in indoor drains like kitchen sinks or toilet drains, foreign objects can be caught within a drain, particularly if it doesn’t have a cover. Grease and fat from cooking and other food items like coffee grounds can also cause clogs, helping to form Fatbergs. While toilet paper is designed to break up within drains, other materials like wet wipes can also contribute to blockages. Surface water drains are only designed for uncontaminated rainwater, as they can connect directly to streams and rivers.

More common as a cause of blockages in an outside drain is leaves and other outdoor debris. If items like leaves, branches, loose soil, and litter get into a drain they can cause serious blockages, leading to water backing up. Using a drain cover can help to minimise the risk of larger items getting into your outdoor drains.

Another potential cause of outdoor drain blockages is tree root intrusion. Tree roots can break through drain pipes underground, damaging your pipes and causing blockages in water flow.

To help keep your drains clean and minimise the risk of future outdoor drain blockages, use a drain cover, and only dispose of permitted liquids within your drain. If you would like to learn more about this subject, we have a useful guide to the 6 most common causes of blocked drains.

How Do I Unblock A Drain Outside?

A lot of smaller blockages in your outside drain can be solved at home. Here are four great methods to unblock outside drains. Before you start, you’ll have to remove your drain cover if you have one, in order to gain full access to the drain.

  1. Unblocking an Outside Drain by Hand

We would recommend using protective clothing before you put your arm within a drain. Drain gloves are available in most DIY shops for a reasonably low price, but if you don’t have any to hand, a combination of rubber gloves with a strong bin bag wrapped around your arm will be a suitable alternative. Using either your hand or a tool like a wire coat hanger, you should be able to reach a good distance into your drain, removing the obstruction, whether it is a physical object or a buildup of mud. If you have mild root ingress within your pipes, the roots can often be removed by hand, simply pulling them from the ground. Once you have removed the blockage, you may require drain relining if the root ingress has sufficiently damaged your pipes.

  1. Using a Hose to Unblock a Drain Outside

Also requiring inserting your arm into the drain, this method requires pushing a hose as far into a drain as it will go and then blocking the opening of your drain around it, using materials like old towels. This will cause a buildup of pressure within your drain, hopefully helping to shift any blockages. When combined with removing as much of the blockage as you can by hand, these two methods can be a great way to unblock an outside drain. It may also be worth bringing a clothespeg when getting far into your drains, as you may encounter some unpleasant aromas. If you have access to a pressure hose this method will be even more effective.

  1. Using Caustic Soda to Clear a Blocked Drain Outside

Sodium hydroxide, also known as caustic soda, can be used as a method to unblock external drains. Caustic soda can be mixed with cold water in a bucket, then poured into a blocked drain and left for at least half an hour. Then, pour a few litres of boiling water into the drain, to help flush it through. This process can be repeated, to help unclog outside drains. Another option is to combine baking soda, washing up liquid, and vinegar within your drain, flushing the mixture through with hot water.

  1. Using Drain Rodding to Clear a Blocked Outdoors Drain

Flexible drain rods are tools designed to break up blockages within a drain, and they can be used to unblock a drain outside. Drain rods are long rods, fitted with a plunger on the tip. They can be inserted into a drain, rotating the drain rod clockwise within your pipe to break up the blockage. Drain rods are available from most DIY stores, and can be used for more serious blockages, and blockages deeper within a pipe. There are some risks to consider, such as drain rods breaking within your pipe.

Your Responsibilities 

Surface water drains outside a house are usually your responsibility as a homeowner to unblock. Public drains outside your property boundary are usually the responsibility of your local sewerage company. In the case that you suspect an outside public drain is blocked, you should contact your local sewerage company and inform them they need to clear blocked drains. If you need further information we have a guide on our website to help you establish who is responsible for a blocked drain.


Professional Drain Unblocking From Coastal Drains

Man Jetting Sewage Drain Outside House

If these methods haven’t worked for you, it may be time to call in a professional plumber to help unblock your outside drain. Coastal Drains offers expert drain unblocking across the South East. We can do full CCTV drain surveys of your outside drain network, detecting and locating issues causing blockages within your pipes. We offer expert drain rodding and high-pressure water jetting, with our advanced technology breaking up blockages deep within your pipes. We can clear blocked drains, whatever is causing the problem.

All of this will be completed by our expert team, who are available for 24/7 emergency call-outs. We offer free, no-obligation quotes for all of our work, and offer a low price guarantee. We are a trusted and vetted company, with a 9.7 rating on Checkatrade after over 450 reviews. Our team is ready to unblock outdoor drains today, simply give us a call.

Author: Greg Child

Greg is an expert in drainage and has been in the business for over 30 years. He's the owner of Coastal Drains Ltd and a very, very friendly chap.

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