Can You Reline a Pipe More Than Once? Everything You Need to Know

Trenchless pipe relining is a cutting-edge solution for damaged or deteriorated pipes, offering minimal disruption and long-term reliability.

However, a common question property owners ask is: Can a pipe be relined more than once?

The short answer is yes—under specific conditions. Let’s explore in detail. 

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Can You Reline a Pipe More Than Once?

The short answer is – Yes

But It Depends on the Condition and Size

Pipes can be relined multiple times, provided the internal diameter after each relining is still sufficient to handle the flow and functionality requirements. Each relining layer reduces the internal diameter slightly, so practicality is the key concern.

Key Factors That Determine Re-Relinability:

• Remaining Diameter: After each relining, the pipe diameter reduces by approximately 4-6 mm. This must be assessed by a professional to ensure sufficient capacity remains.

• Pipe Condition: The existing pipe and previous liner must still be structurally sound, free of extensive collapse, or root infestation.

• Type of Pipe: Clay, PVC, cast iron, and concrete pipes respond differently to multiple relinings. Cast iron, for example, often becomes brittle and may not support another layer.

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When Multiple Relinings Are Not Recommended

In certain cases, it’s better to replace or partially excavate and replace the section of pipe rather than attempting a second or third relining:

• Severe deformation or collapse

• Previous poor-quality relining

• Persistent tree root infiltration

• Heavily scaled or corroded internal walls

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Ideal Scenarios for Re-Relining Pipes

• Minor surface cracks reappeared years after initial relining

• Localised issues in otherwise stable relined sections

• Building extensions requiring added flow capacity with upgraded junctions

• Reconfiguration of plumbing systems requiring sealed-off branch connections

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How Professionals Assess for Second Relining

1. CCTV Drain Inspection

High-resolution cameras allow experts to view the internal pipe conditions and check for obstructions, root ingress, or flaws in the existing liner.

2. Diameter Testing

Pipe gauges are used to measure whether there’s enough internal space to accommodate another liner without impairing flow efficiency.

3. Structural Integrity Analysis

The health of the original pipe and previous liner is tested to ensure that it can support another epoxy-saturated liner without failure.


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Common Pipe Types Suitable for Multiple Relinings

Pipe Material	Re-Relinability	Notes
PVC	Moderate	Smooth interior; depends on age
Cast Iron	Low	Brittle over time, may crack further
Clay	Moderate-High	Brittle but compatible with liners
Concrete	High	Durable and wide internal diameters
Orangeburg	Not Suitable	Organic material, collapses easily

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How Long Does Each Relining Last?

Typically, a high-quality pipe relining job can last up to 50 to 100 years with proper maintenance. A second or third relining should also meet similar standards if done using modern epoxy resins and proper curing methods.

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Cost Implications of Multiple Relinings

A second relining usually costs similar to the first, but may involve more labor if de-scaling or additional preparation is required. Factors influencing cost:

• Pipe diameter and length

• Accessibility

• Existing liner’s condition

• Complexity of pipe layout

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Maintenance Tips to Extend Life of Relined Pipes

• Avoid flushing grease, wipes, and non-biodegradable materials

• Regular drain cleaning using high-pressure water jetting (not chemical cleaners)

• Annual CCTV inspections for early detection of cracks or obstructions

• Root barrier installations if tree root infiltration was an issue previously

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Is a Second Pipe Relining Worth It?

If the existing pipe system meets the structural and spatial criteria, relining a pipe more than once is a cost-effective, low-disruption, and long-lasting solution. Always consult with a licensed and experienced plumbing professional who uses high-grade materials and modern CCTV equipment.

For properties with ageing infrastructure, multi-layer relining can save thousands of dollars in excavation and restoration costs, making it an excellent option when done correctly.

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Need an Expert Opinion?

Our team of Renoline trenchless plumbing specialists can perform a assessment and advise whether your pipes are eligible for a second relining. Contact us today for a free consultation and CCTV inspection quote.