Outside Kitchen Drain Overflowing? Common Causes & Easy Solutions

Ever found yourself thinking, “Why is my kitchen sink’s outside drain blocked?” As drainage specialists, we know that this can become a real headache for property owners.

If you’re a business or a homeowner, you are responsible for your outdoor sink drain systems. This means that they require continuous maintenance to prevent further issues. 

Whether you’ve spotted an overflowing outside kitchen drain following heavy rain or if it’s blocked from food waste and debris, understanding what is causing the problem can save time, stress, and unnecessary costs. 

As drainage experts, we’ve put together this handy guide to help you understand what causes an overflowing drain, how to spot signs, and how to fix drainage problems. 

What Causes an Overflowing Outside Drain? 

While there can be many reasons why your outside kitchen drain may be overflowing, blockages are often the most common cause for water escaping from your pipes.

Food Waste

Without straining and throwing waste in bins, excessive food waste, such as rice, pasta, coffee grounds, and vegetable peels, can end up getting washed down the sink. Emptying dregs from sauce bottles and jars into kitchen drains can cause drainage problems, as the thick residues can build up, congeal inside the pipes, and eventually lead to stubborn blockages and also create bad odours.

Grease Build Up

Fats, oils, and grease solidify over time, meaning that they can stick to your pipes and cause a buildup if they aren't disposed of correctly. 

Leaves and Debris

Kitchen drains that are within proximity to trees and shrubs can end up with leaves and debris in the drainage system. This can cause a build-up, preventing water from passing through the pipes.

Tree Roots

As trees require moisture to grow, their roots can find their way into cracks or joints in your systems. Small openings can result in roots spreading throughout the pipes, potentially causing structural damage in the process. If you suspect there's tree roots in your drain, check out our article on common causes, signs, and fixes. 

Heavy Rainfall

During storms and periods of heavy rain, your pipes may struggle to cope with unusually high volumes of water, particularly in older or poorly designed drainage systems, which can result in puddles and excessive water pooling.

Pipe Damage

Over time, outside pipes can weaken from ground movement, wear, or corrosion. Cracks can reduce the pipe’s ability to drain effectively, causing leaks and resulting in blockages. 

How to Identify Signs of a Blocked Outside Kitchen Drain

Spotting signs of overflow early can prevent the issue from causing serious flooding or damage. At Drain Doctor, we recommend looking out for: 

Bad Odours

Strong and unpleasant smells coming from your drainage systems can be the result of food waste or stagnant water trapped inside.

Slow Draining Sink

When water takes longer to drain than usual, it can be a common sign that your drainage may be partially blocked.

Gurgling Noises

If you hear gurgling sounds whenever you use your kitchen sink, it’s likely due to air struggling to flow through the drainage pipes.

Standing Water

Water pooling around your drain or patio area often means that there is a blockage below the surface and in your pipes.

You can learn more about slow drainage in our article Why Is My Water Draining So Slowly? Causes, Signs & Solutions.

How to Fix Outdoor Sink Drain Issues

There are several ways in which you can fix your outdoor kitchen sink drainage and prevent overflowing. Here are a few simple steps to follow to remove blockages:

1.     Remove Debris

First, lift the drain cover and remove any visible leaves, debris, or food waste. We recommend using a pair of gloves and a bucket to collect materials. 

2.     Flush with Hot Water

Next, pour hot water into the system mixed with washing-up liquid to eliminate grease and fat buildup. Don’t use boiling water, as this can cause damage to the pipes. Continue to do this regularly to ease water flow. 

3.    Use a drain rod or plunger

For deeper blockages, using a set of drain rods can help dislodge the build-up. Insert the rod carefully and twist clockwise to push anything that is blocking the pipes. 

A plunger can also be used to ease smaller clogs. To do this, simply place the plunger over the drain and add some water to cover the plunger head, and pump up and down vigorously for 15-20 seconds until clear. 

4.    Avoid using chemicals

Chemical unblockers can cause long-term damage to pipes and are harmful to the environment. As a result, it’s worth using safe, mechanical methods to clear any blockages.

5.    Regular maintenance

We recommend completing regular maintenance to ensure your drainage systems remain clear. Even just being aware of the causes and signs will allow you to have a proactive approach to maintaining your drainage systems:

• Ensure you dispose of food waste and grease correctly to prevent it from being washed down the kitchen sink.
• Check your outdoor kitchen sink monthly and remove visible debris.
• Consider installing a drain guard to prevent leaves and debris from entering the system.

6.    Get Professional Drainage Assistance

If the problem persists, there may be a bigger problem at play, such as poor drainage systems. This can be the result of pipes that are too narrow or slow-draining.

It’s important to ensure you have a fully functional drainage system so that you don’t get overflowing or blockages. Ensuring drainage systems are correctly installed will allow you to confirm that the systems work properly.   

It’s always worth getting a professional opinion on your outside kitchen drainage system to ensure that you identify signs early and that it is done correctly.  

Trusted For Over 30 Years

At Drain Doctor, we've been treating drains for commercial businesses and homeowners for over three decades. Our experienced drainage engineers are highly skilled and can help provide a quick diagnosis and repair for overflowing outdoor kitchen sinks. We can offer professional drainage installation services if you have outdated or incorrectly installed systems or damaged pipes.  

With our experts, you can rest easy knowing that your property is safe from recurring issues and water damage. Get in touch with your local drainage engineers today to find out more.