Soil Stack Cleaning: A Handy Guide

You’ve got a sneaky suspicion of a blocked soil stack – and a foul smell or a toilet that drains very slowly could be evidence that you’re right to suspect that something’s amiss. While this means trouble might be brewing, it’s always best to diagnose a problem earlier, rather than later.

It’s true that unblocking a soil stack is not the easiest – or pleasant – job out there, which is where we come in here at London Drainage Services.

Need help with soil stack cleaning in Central London, London or the Home Counties? Speak to one of our team today on: 07563 571200 / 01727 875975 or email:

But first we’re giving you some information you think you’ll find useful in correctly identifying the issue.

Is the pipe made from cast iron, for instance? If so, it will almost definitely be cleared by way of the vent above the roof. While modern plastic stack is easier to clean, it still presents something of a job for a draining professional – and is not a problem you’ll find easy to tackle yourself.

What is Vertical Soil Stack Cleaning

What is Vertical Soil Stack Cleaning?

So, what exactly is vertical soil stack cleaning – and why would you require it?

Before understanding how we’d go about the cleaning process, you must first know a little more about the purpose of the soil stack or soil vent pipe (SVP). And while it sounds quite technical, it’s simply used to carry gases and fumes from your home or business’s plumbing system in a similar way that a chimney carries smoke and fumes from your fireplace.

Grey or black water will leave the toilet, sink, bath or shower, before flowing through a waste water pipe – an upright pipe in the plumbing system whose job it is to allow gases and air to escape upward.

Gravity will then do its job of pulling the water onto the septic system or sewer and everything will be disposed of properly and in as smooth and hassle-free way as possible.

Venting gases into the atmosphere where they dissipate fast – without turning your home and street into a foul-smelling sewer (not nice, let us tell you!) – the soil stack has a vital role in your plumbing system.

The pipes tend to be covered with vent covers or screens; these prevent insects, birds and even small animals from getting in from above – another thing which will cause disruption to the system. Generally a secondary deterrent, these covers ensure that – in much the same way as the smell of the soil stack itself will help – few animals or insects will be tempted enough to enter.

It’s therefore hugely important you maintain the effectiveness of your drains by ensuring you do your best to keep them clear.

Cleaning the Soil Stack

Cleaning the Soil Stack: How To

At this stage, you may be wondering why you’d even need to clean the soil stack? After all, isn’t this a useless task, given that the only thing that escapes from it is air? Why would it need to be cleaned, if that’s the case?

Well, there are several factors which can result in a blockage in your soil stack – which can escalate to cause a much bigger problem for you. And trust us, you won’t want that! Here are just some of those factors to watch out for:

  • If you’ve been plunging the toilet incorrectly, you’ll create a blockage. Any materials flowing from the toilet to the sewer will be forced through the pipe when you plunge, with water and loose materials taking the easiest path and therefore creating a blockage
  • Cotton buds are a big culprit! These will float at the top of the pipes when your toilet is flushed, meaning they will become stuck in or near the soil stack. Continuing to catch other debris, you’ll soon have a blockage on your hands if you don’t notice the problem and deal with it quickly
  • Becoming lodged in the soil stack to create a bigger issue over time, dirt and debris might be the reason when it comes to a blocked soil stack
  • Nearby plants can cause a blockage, as roots will grow upward. Any that therefore enter the plumbing pipes and end up in the soil stack will create a blockage that must be dealt with.

How Messy is Soil Stack Cleaning?

How Messy is Soil Stack Cleaning?

We’ve said it earlier in this guide and we’ll say it again: soil stack cleaning isn’t a glamourous or easy job. It’s messy and will require the help and expertise of a professional. So much for thinking you’ll save money by having a go yourself!

Unless you’re trained in soil stack cleaning, we really wouldn’t advise that you tackle the issue yourself, though. For one, heavy gases can build up inside the pipes that might be flammable, which means protective clothing and glasses at the very least are a must.

The good news is, here at London Drainage Services we operate around the clock to ensure we can sort out any job to get you back up and running as soon as possible. When it comes to clearing and cleaning blocked drains in general, we can do everything from drain jetting or vacuuming to undertaking any unnecessary drain repairs.

We can also install drain linings and we’ll always use the most advanced drain clearance technology and equipment to ensure the job is done quickly and efficiently – get in touch for more information.

Need help with soil stack cleaning in Central London, London or the Home Counties? Speak to one of our team today on: 07563 571200 / 01727 875975 or email:



  • Hi, we need our soil vent unblocked. As we are currently having a loft conversion done, there is scaffolding erected which provides good access. Thought we should take the opportunity to get it done.

  • We had our drains flushed recently but there is still an intermittent foul odour and we do not know where it is coming from. We found you on the Internet and wondered if our soil stack was blocked and what we can do to try to find out and your fees for clearing it.

Leave a Reply

Your email address will not be published. Required fields are marked *