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Example of a damaged pitch fiber pipe showing visible cracks and wear.

Pitch fibre pipes, widely used from the 1950s to the 1970s, present several issues today, including deformation, root ingress, and collapses. This comprehensive guide explores the causes, signs, consequences, and solutions for problems associated with pitch fibre pipes, helping homeowners understand and address these challenges effectively.

What are Pitch Fibre Pipes?

Pitch fibre pipes are drainage pipes composed of wood cellulose impregnated with coal tar. They were used extensively from the 1950s to the 1970s for their affordability and light weight. Over time, however, their structural integrity can deteriorate, leading to serious issues.

Historical Use and Decline

While initially hailed as a cost-effective solution, pitch fibre pipes have shown long-term weaknesses. As a result, many properties now face the consequences of using this outdated material, leading to frequent repairs and replacements.

Common Problems with Pitch Fibre Pipes

Deformation and Collapse

One of the primary issues with pitch fibre pipes is their tendency to deform and collapse. Exposure to water, chemicals, and pressure causes the pipes to lose their shape, leading to blockages and reduced flow capacity.

Causes of Deformation

Water Exposure: Continuous contact with water softens the pipe material.

Chemical Reaction: Interaction with household chemicals weakens the pipe structure.

Physical Pressure: External pressures from soil movement or traffic can cause pipes to cave in.

Root Ingress

Tree roots are naturally attracted to the moisture inside pipes. Pitch fibre pipes are particularly vulnerable to root ingress, where roots penetrate and eventually block or break the pipes.

Impact of Root Ingress

Blockages: Roots obstruct the flow of water, causing backups.

Structural Damage: Persistent root growth can crack and break the pipes, leading to leaks.

Blockages and Overflows

As pitch fibre pipes deform and roots infiltrate, blockages become more frequent. This leads to overflows, which can cause significant property damage and health hazards.

Consequences of Blockages

Health Risks: Overflowing sewage poses serious health risks due to contamination.

Property Damage: Water damage from overflows can ruin foundations, landscaping, and interiors.

Signs of Pitch Fibre Pipe Problems

Slow Draining Water

One of the most common signs is slow draining water in sinks, bathtubs, or toilets. This occurs because the collapsed or deformed section of the pipe obstructs normal water flow.

Unpleasant Odors

Foul odors emanating from drains or around your property can indicate sewage buildup due to blockages or leaks in pitch fibre pipes.

Damp and Waterlogged Areas

Water escaping from damaged pipes can saturate the surrounding soil, leading to damp patches or waterlogged areas in your garden or lawn. Indoors, you may notice damp walls or floors.

Sinkholes and Cracks

Severe cases of collapsed pipes can cause the ground above to sink, forming sinkholes. You might also see cracks in walls, driveways, or pavements, indicating underlying drainage issues.

Rodent Infestations

Damaged pipes can create entry points for rodents. An increase in rodent activity around your property might be due to a collapsed drain providing easy access.

Drainage engineer inspecting a damaged pitch fiber pipe.

How Professionals Fix Pitch Fibre Pipes

CCTV Drain Surveys

To accurately diagnose the extent of the damage, professionals use CCTV cameras to inspect the interior of the drainage system. This non-invasive method provides a clear view of any deformations, blockages, or root ingress.

Pipe Relining

For minor collapses or deformations, pipe relining is a less invasive solution. A resin-soaked liner is inserted into the damaged pipe and then inflated, forming a new, durable pipe within the old one.

Pipe Bursting

This technique involves breaking the old, damaged pipe while simultaneously pulling a new pipe into place. It’s more efficient than traditional excavation but might not be suitable for all situations.

Excavation and Replacement

In severe cases, excavation might be necessary to replace the damaged sections of the pipes. While disruptive, this method ensures that the drainage system is fully restored.

Preventive Measures

Regular Inspections

Scheduling regular inspections with a professional can help identify and address minor issues before they escalate into major problems. These inspections can detect early signs of wear, blockages, and potential collapses.

Proper Waste Disposal

Avoid disposing of grease, non-degradable items, and harsh chemicals down the drain. These substances can accelerate the deterioration of pitch fibre pipes.

Root Barrier Installation

If you have trees near your drainage system, consider installing root barriers to prevent roots from infiltrating and damaging the pipes.

Ground Stability Management

Ensure the ground around your property remains stable, particularly if you live in an area prone to heavy rainfall or ground movement. Proper drainage and landscaping can help maintain soil stability and protect your pipes.

Unblockers engineer in high-visibility jacket standing ready on a street for maintenance work


Understanding the issues caused by pitch fibre pipes and taking proactive steps to address them is crucial for maintaining a functional and safe drainage system. Regular maintenance, professional inspections, and mindful practices can help prevent costly repairs and ensure the longevity of your property’s plumbing infrastructure.


1.0 What are the signs of pitch fibre pipe problems?

Signs include slow draining water, unpleasant odors, damp and waterlogged areas, sinkholes, cracks, and increased rodent activity.

2.0 How do professionals fix pitch fibre pipes?

Methods include CCTV drain surveys, pipe relining, pipe bursting, and excavation and replacement, depending on the extent of the damage.

3.0 Can pitch fibre pipes be repaired without excavation?

Yes, less invasive techniques like pipe relining and pipe bursting can often fix the damage without extensive digging.

4.0 How can I prevent issues with pitch fibre pipes?

Regular inspections, proper waste disposal, installing root barriers, and managing ground stability are key preventive measures.

5.0 Are pitch fibre pipes still used today?

No, due to their known issues, pitch fibre pipes are no longer used in modern plumbing installations. However, many older properties still have these pipes in place.

Protect Your Home Today!

Don’t let outdated pitch fibre pipes cause costly damage. Contact Unblockers.net now for a thorough inspection and modern solutions. Ensure your drainage system is efficient and worry-free.


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