Identifying Pitch Fibre Pipes

Cardboard piping

For people who don’t work in the industry, knowing what function different types of pipes  carry out at  our properties is unlikely – to many, they’re just a way of carrying  our water and waste away from the premises. However, plumbing systems are in reality sophisticated networks that play a crucial role in maintaining clean, sanitary premises. With that said, like most systems in our homes and businesses, certain technology become outdated and in certain instances, obsolete. Pitch fibre pipes are one example of these systems, and we’re going to look at how you can identify their existence in your property.

What are pitch fibre pipes?

Pitch fibre pipes were very popular in houses built between the 1950s and the 1970s, thanks to their relatively cheap price, which in turn was down to the fact they were made from wood cellulose, injected with inert coal tar pitch. They were used in countless buildings for years perhaps due to the ease of installation – there was no need for any sand or cement, and the system used push-fit joints which were extremely simple to use, as opposed to the joint haunching required for clay pipes. While only popular for a short period time, properties all over the world, including the UK, still have pitch fibre pipes, and as time ticks on those pipes will be nearing the end of their useful life.

Pitch fibre pipes have an estimated useful life of around 40 years – the reason for the short lifespan being that over time, the pipes endure delamination. Delamination means the loss of adhesion so layers separate, which leaves the pipe weaker and more prone to collapse or leakage. The process is usually a gradual one, but where high temperatures and chemicals are involved, the process can be sped up. There are also a number of other issues that face pitch fibre drainage:

  • They can also deteriorate through age, stress or excessive weight
  • Water can seep out as the pipe becomes permeable, which can cause subsoil to wash away. This, in turn, creates subsidence
  • These leaks can attract plant roots, which risks instigating the process of root ingress, whereby plant roots infiltrate pipes and damage them
  • Hot water, oils and fats can cause the tar in the pipes to soften, which weakens them

It is estimated that every year, over 50,000 homes experience drainage issues that are linked to the presence of pitch fibre pipes. These issues consist of blockages and overflowing, thanks to factors like hot water, ageing structures and root ingress. It is thought that any drainage systems that were installed between the 1950s and the 1970s will be pitch fibre-based, thus will have either exceeded or will be approaching the end of their working life.

How do I spot pitch fibre pipes?

The best, most effective way to check your piping system is to arrange for a drainage survey. CCTV surveys will be able to immediately and accurately identify everything from the material your pipes are made of to the location of any cracks or damage. If you do have pitch fibre pipes in your property, there is no real DIY alternative – consult your drainage company to check whether there are any repairs that can be made or if the pipes need complete replacement.

I think I have pitch fibre pipes installed: what are my options?

As we mentioned earlier in the piece, delamination is a serious problem for these types of drains, and if issues are left untreated, the pipe can collapse entirely. If you noticed a fault within the traditional 40 year ‘useful period’ of your pipes, they could be re-lined and/or re-rounded. However, as we’re now in 2018, most pitch fibre pipes are more than 40 years old, in which case it’ll be time for them to be replaced. While this may seem like a major overhaul, it’s crucial that your drainage systems are as safe as possible – something that cannot be guaranteed with pitch fibre drains. The replacement of the drains will be carried out by trained engineers with specialist machinery – on the face of it, the process might seem disruptive, but in reality it can be very efficient.


Express Drainage Surveys are experts in providing CCTV drain surveys and inspections for domestic and commercial properties alike. If you’d like to know more about the work we do, please feel free to get in touch with us today and we’ll be more than happy to help you with anything you need.