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What’s the difference between a soil pipe and a waste pipe?

Soil pipes are vital aspects of every plumbing system, but they are so often confused with waste pipes, which whilst similar, have very different functions. So, if you’re looking to replace your soil pipe, it’s imperative that you know the differences to ensure your drainage network works seamlessly.

Here at Total Pipes, we supply both soil pipes and waste pipes and are often asked about the key differences, so to help, we’ve put everything you need to know here in one place – enjoy!

What is a soil pipe?

The main objective for a soil pipe is to carry waste from the toilet, urinal or bidet to the sewers. They are usually made using plastic polyvinyl chloride (PVC_ and acrylonitrile butadiene styrene (ABS).

What is a waste pipe?

Waste pipes carry water away from sinks, baths, showers and washing machines. They too are usually made from PVC or ABS, but older (pre-1960) waste pipes were often made using iron or steel.

So why the confusion?

The truth is that if you’re not a qualified plumber, navigating between these two drainage systems can be difficult. Both pipes sound very similar in what they do, and that’s largely because they are! Both carry waste away from the home, but there are some crucial differences that separate the two.

More about soil pipes…

A soil pipe also goes by the name of a soil vent pipe, because of the built-in vent system to help prevent a build-up of harmful gases and unpleasant smells. It may be something you don’t think of, why would you, but this ventilated system is crucial to stop your home smelling of waste. The vent is usually situated at the top of a building, placed upon soil pipe stacks, so that waste is ventilated safely into the atmosphere.

And, probably most obviously, soil pipes are of the right dimensions for waste to pass through the piping system without getting blocked.

More about waste pipes…

Usually smaller in diameter, waste pipes aren’t designed to carry anything other than liquids, which is why they can become blocked if food is scraped into the sink for example. There is no need for a ventilation system with a waste pipe as wastewater is generally considered safe and thus needn’t be vented in the same way as solid waste.

Ask the professionals

Here at Total Pipes, we advocate DIY wherever possible, but there are some things that should be left to the professionals, and plumbing is often one of them. If you’re unsure which type of plastic piping you need, we recommend getting in touch with our team. We’re experts at what we do and can help to guide you through the buying process to ensure you’re getting the right parts for the task at hand.

Call us today on 01254 382000, or if you’re confident about the part you need, order your soil pipe online.