In the UK, there are typically two types of drainage systems. Although they achieve the same thing in terms of directing water away from your property, they do so in a slightly different way.

In this blog, we will outline what the differences between these two systems are, as well as the importance of handling rainwater appropriately.

If you require any drainage services from a reputable company with experienced technicians, give us a call today on 0808 164 0776.

What Is the Difference Between a Single-Pipe and Double Drainage System?

Modern homes tend to have a single-pipe system which involves one vertical large-diameter pipe (called a soil stack) running inside the property. In older more traditional homes, it involves a dual-pipe setup. Wastewater and soil water are taken separately to the public sewer system.

What Is the Difference Between a Single-Pipe and Double Drainage System?

How Do Single-Pipe Systems Work?

As mentioned, in modern times drainage companies have transitioned to a single-pipe system. These large-diameter vertical pipes connect your plumbing appliances upstairs, such as basins, showers, and baths, and take any waste and water to the underground drainage system.

Downstairs appliances might be attached to this pipe, although this can vary from system to system. However, almost always a downstairs toilet will be connected directly to the drainage system in order to take the soiled water and waste away directly.

These pipes also boast ventilation. The soil stack pipe will travel all the way up to the top of the house and poke out of the top, allowing any unpleasant smells from the drainage system to drift away, far from any windows or doors keeping it out of your home.

Although this style of system would not have been installed originally in older homes, many have been updated to this more modern method.

How Do Double-Pipe Drainage Systems Work?

In older drainage systems, wastewater and soil water were taken to the underground system in two separate pipes.

The soil water from toilets is connected to a vertical soil pipe which runs outside the home, attached to one of the walls. These have a large diameter and reaches above the roof to provide ventilation.

Wastewater, however, is taken away from the home in a much thinner vertical pipe. This reaches only as far as the first floor, and all the wastewater pipes from baths/showers and sinks will connect to this, specifically into a ‘funnel’ called a hopper head.

When this pipe reaches the ground, it will dispense the water into a gully. This gully should be covered my mesh or a grid so as to stop any potential clog materials from entering the system.

This is why many people have chosen to update their system. It is entirely possible for the grid to become blocked as debris and detritus build up in the guard. When this happens, the water will have nowhere to go, and if you haven’t noticed, your garden may quickly become flooded.

Even if an overflow does not take place, bad smells and odours can start to emanate from the pipes and up through your plugholes.

How is Rainwater Dealt With?

It is vital that rainwater is dealt with separately from waste and soil water from your home. This is because, during torrential spells of rain, the sheer amount of water the system will have to deal with can overload the system and cause overflows or even bursts.

Rainwater will have to be collected in guttering around your roof and funnelled into a downpipe. This downpipe can dispose of this water in two ways:

  • The downpipe can eject the liquid over a gully covered by a grid.
  • The downpipe can be connected directly to the underground drainage system.

Both of these methods can work perfectly, but it is vital that rainwater is taken away from your home so that it does not build up in your garden or fall unguided from the edge of your roof.

Our Company

At Clark Drainage we have years of experience in installing functional drainage systems in both domestic and commercial settings. From making extensive repairs and updates to ripping out and installing a new system in its entirety, no job is too big or small.

We also carry out emergency repairs and scheduled maintenance. With technicians available round-the-clock 365 days a year, there is always someone available to carry out effective, reliable, and affordable repairs.

To speak to one of our operators today about what we can do for you, give us a call now on 0808 164 0776.

Alternatively, complete our contact form, and one of our personnel will be in touch to organise a job as soon as possible.

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ReviewsWhat our customers have to say about us
  • 14/10/2025

    Bang on time, job done fast.

    Turned up bang on time and were done quicker than expected. Cheers lads! Was expecting a drawn-out job, but they clearly knew what they were doing and just cracked on.

  • 10/10/2025

    Explained everything so simply.

    I had no clue what was going on with our pipes but they explained it all so clearly. Felt completely reassured the whole time and appreciated how patient they were with my questions.

  • 18/09/2025

    Down to earth and skilled.

    Really down-to-earth team who know what they’re doing. Cheers for the help. From the moment they turned up, it was clear we were in good hands. They made the whole process simple and stress-free.

  • 17/09/2025

    Didn’t let us down.

    They were recommended by a mate and didn’t disappoint. From the first phone call to the final clean-up, it was clear they knew their stuff. We felt confident we were in good hands the entire time.

  • 18/08/2025

    Surprisingly brilliant.

    Never thought I’d be raving about a drain company but here we are. They were just that good. Helpful, friendly, honest – and most importantly, they fixed the problem without any stress.

  • 18/08/2025

    Detailed and really useful.

    Had a CCTV survey done. Report was super detailed and made it easy for our builder.

  • 17/08/2025

    Garden sorted, no more flooding.

    Cheers to Clark Drainage for getting our garden sorted after that downpour. Great job. We’d tried a few things ourselves with no luck, but they came in, identified the issue quickly, and had the drainage working perfectly again.

  • 17/08/2025

    Quick turnaround and sorted fast.

    The lads came out next day and fixed the issue in half an hour. It had been bothering us for weeks, so to see it sorted that quickly was honestly a huge relief.

  • 16/08/2025

    Did it right first time.

    We’d had other companies round who couldn’t fix it. Clark Drainage had it sorted in one visit. The difference in professionalism and competence was night and day. Absolutely brilliant from start to finish.

  • 14/08/2025

    Proper pride in their work.

    It’s not glamorous work but they do it with a smile and real pride. Can’t say I’ve ever seen someone so happy clearing a drain, but they made the whole thing stress-free and even a bit fun.