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How To Connect A New Toilet To Your Existing Soil Pipe

Removing your old toilet? Here are our top tips on how to connect your new one to your existing soil pipe

Whether you’re remodelling your bathroom, or your old chamber has been giving you problems, you’re probably wondering if you can connect your new toilet to your existing soil pipe.

The answer is: yes, you can! And it couldn’t be easier.

Unless it’s in a serious state of disrepair, there aren’t many reasons why you should need to replace your soil pipe just because you’re installing a new toilet.

But how do you connect a new toilet to your soil pipes?

Our team here at Total Pipes share some of their top tips in this post.

What are soil pipes?

Soil pipes are an essential part of every plumbing system.

Each time you flush the toilet, the soil pipes in your bathroom carry all the dirty water from your home to the sewer.

Soil pipes are often confused with waste pipes, and whilst they are remarkably similar, your waste pipes carry water away from your sinks, baths, and showers – rather than exclusively from your toilet.

Where can I find my soil pipes?

Soil pipes can be found easily in one of two places:

  • Above the roof
  • On the side of your house

If you live in a more up-to-date property, keep an eye out for a plastic, tree-like shape branching out on the side of your home. This is your soil pipe.

Usually, older properties will have a cast iron soil pipe protruding from the roof.

So, how do I connect my new toilet to my soil pipes?

Connecting a new toilet when it’s the only one in the house is simple, as it only needs to be refitted where your old toilet was. You might need to play around with the soil pipe measurements, but other than that, it’s virtually foolproof.

However, it’s a different story if you have more than one toilet in your house.

Before you begin, make sure that you’re not fitting a second toilet on the same horizontal section as another. The last thing you need is for someone to flush one side, and have it affect the side you’re working on.

First, measure your toilet’s new flange and cut your pipe accordingly so that it’ll fit in nicely.

Then add a slip coupling to your soil pipe at the end where the main stack is.

Next, connect the flange on the opposite end using a push-fit connection.

The final two steps are to slide the slip coupler up so that it connects the soil pipe to the new toilet’s flange, and then to seal both ends with more slip couplings.

If you’re not the best at DIY jobs like this, we recommend getting in touch with a plumber who can come to your house and do it for you.

Need further advice?

Whether you need tips on how to install a new toilet or are on the hunt for a high-quality replacement soil pipe, we’ve got everything you need here at Total Pipeline Systems.

Browse our range online, add everything you need to your basket, and head over to our secure checkout to have your items delivered directly to your door.

If you have any questions, give us a call today on 01254 382 000, or send your enquiry by email to and we’ll get back to you.