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Common causes of blocked drains and how we unblock them

| Michael Quinn

A particular worry for many homeowners is what to do if they find a blocked drain. This sort of problem can cause your drainage systems to run slower or even to back up and overflow entirely if left too long.

The most common causes of blocked drains

There are many reasons why drains become blocked, and we have labelled the most common below:

A photo of a drain being cleared of fats, oil and grease.
A photo of a drain being cleared of fats, oil and grease. Are you aware of how much goes into your drains?

Food waste, oils, grease and fat

Perhaps the most common causes of blocked drains are these residues from cooking, which people pour away or let go of their drains. Unfortunately, these products also build-up, solidify, and cause drain blockages. If the problem is left, it could cause the pipe to back up and overflow.

To prevent this from happening, pour any oils or grease from your cooking into a pot and throw it into your household waste, rather than pouring it down your kitchen sink, and try not to let particles of food get washed down there. If there is already a small buildup in your pipes, you can also pour hot water down the drain to break it up. Generic kitchen waste (including soaps and dishwasher detergents) also contribute to the formation of fatbergs.

Hair and soap suds

Whenever you wash your hands, hair or body in the sink, bath or shower, debris such as soap and hair strands can easily be washed into the drains, clogging the pipes when the buildups solidify.

To avoid this, you may wish to consider buying a drain cover to catch debris before it can make its way into your drains. Alternatively, you can clean and remove any hair strands that may have fallen in to alleviate the risk of blockages.

Dirt and leaves

A common cause of blocked drains outside your home (particularly in gullies or surface water drains) will be debris that has been blown or washed into them. Usually, this will be mud, silt, dirt or leaves, and can often be made worse if a garden is not tended to regularly or if the weather is bad. 

It is difficult to prevent these from being washed into your drains, but preventing them from causing a blockage is possible. Using a drain guard to cover the gully, large items such as leaves and larger, compacted pieces of mud will be stopped and pulled free. Some gullies have a gully pot that can be removed and emptied as and when required. Some blockages inside the drain can be broken up using a drain rod.

Tree roots

Another possible cause of blocked drains is tree root ingression. Any small crack or leak in a pipe can lead to a tree root coming through, which will then grow into your drainage system. This will not only cause a blockage but can cause a significant amount of damage to your pipes.

To avoid this, you should make sure that your pipes are in good condition. We can also assess whether tree roots have entered your drain through a CCTV drain survey.

Foreign objects

Small objects often accidentally get washed into drains. Anything from keys to a child’s toy can cause the issue and become a blockage when they get stuck.

An image of empty toilet rolls - are you aware how much do you put down the toilet?
An image of empty toilet rolls - are you aware how much do you put down the toilet?

The only way to prevent certain items from being sent down the drain is to be careful and not have them near drains they could fall into. Toiletries and other hygiene products such as sanitary wear, cotton buds or baby wipes should be placed in a bin instead. It would help if you also were careful with how much toilet paper you flush down the toilet, as using too much at once can cause blockages as well.

Mineral buildups

In areas with hard water, minerals can form buildups in the water, creating a limescale layer. If limescale builds up in the pipe, it reduces the pipework's diameter and can eventually lead to blockages. One way of combating this is to have a water softener installed, or you can contact our team at ASL and opt for our descaling service.

How we handle the common causes of blocked drains

At ASL, we have a range of methods for clearing out blocked drains. Which method we use will depend on the type of blockage, the location of the affected drain and the severity of the issue.

Below are our main services for cleaning and clearing blocked drains:

  • Drain rods and snakes
  • Chemical products
  • Wet vac
  • High-pressure drain jetting (this includes descaling)

For a full breakdown of our services, visit our page on how we professionally unblock drains.

If you are having trouble with a blocked drain on your property, we could help you.

Don’t delay we can help you today!

Call 0800 181 684 for all your drainage needs.

Our HQ is based in Guildford, but we cover the whole of Surrey, Parts of Berkshire, Hampshire, West Sussex and South West London.

See the map below or our 'areas covered page' for our services reach and use our postcode checker.