Photo by Castorly Stock on Pexels
If you've had a plumber clear tree roots from your sewer line more than once, you already know how frustrating the cycle can be. Roots get cut out, the drain flows freely again, and a year or two later, the same problem is back. Cutting the roots out treats the symptom, but it doesn't fix the crack or joint gap the roots used to get in in the first place, which means they'll keep coming back until that entry point is actually sealed.
This is where pipe relining comes in. Rather than just removing the roots that are already there, relining addresses the damage that let them in to begin with. Here's how that actually works, and when it's the right fix.
Why Tree Roots Get Into Pipes in the First Place
Tree roots don't damage a perfectly intact pipe. They're drawn to the moisture and nutrients inside sewer and drain lines, and they exploit existing weaknesses to get in, typically:
- Small cracks that have developed in ageing pipes
- Gaps at pipe joints, particularly in older clay pipe systems where joints weren't sealed as tightly as modern materials allow
- Minor misalignment between pipe sections, which creates a small opening roots can work their way into
- Pre-existing corrosion or pitting in metal pipes
Once a root finds its way in, even a small one, it continues to grow inside the pipe, widening the original gap and increasingly restricting flow. This is why root intrusion problems tend to get worse over time rather than resolve on their own. If you're not sure whether root intrusion or another issue is behind your blocked drains, our guide on root intrusion in drains covers how to spot the signs and what typically causes it.
Why Cutting Out Roots Alone Doesn't Solve the Problem
Mechanical root cutting or hydro jetting can clear roots from a pipe effectively, and it's often the right immediate step when a drain is actively blocked. But it only removes what's growing inside the pipe right now. The crack or gap the roots used to get in is still there afterwards, which means it's only a matter of time before new roots find the same opening.
For homes with recurring root intrusion in the same section of pipe, this cycle of clearing and re-blocking is usually the clearest sign that the entry point itself needs to be sealed, not just the roots removed.
How Pipe Relining Stops Roots From Coming Back
Pipe relining installs a new, jointless liner inside the existing pipe, which effectively seals off the cracks and gaps that roots were using to get in. Because the liner is a continuous, seamless surface with no joints of its own, it removes the vulnerable points that made the original pipe susceptible to root intrusion in the first place.
This is different from simply repairing a single crack. Relining resurfaces the entire treated section, so any smaller, not-yet-obvious weak points along that length are sealed at the same time, not just the one that happened to let roots through this time.
When Relining Is the Right Fix for Root Damage
Relining is generally a strong option for root-damaged pipes when:
- The pipe itself is still structurally intact, just cracked or gapped at specific points
- Root intrusion has been recurring in the same section despite previous clearing
- A CCTV inspection shows multiple minor cracks or joint gaps rather than one severely collapsed area
- The property has established trees near the sewer line likely to cause ongoing root pressure
When You Might Need More Than Relining
In some cases, root damage is severe enough that relining isn't the complete answer on its own:
- If roots have caused the pipe to collapse or deform significantly, a liner won't have a stable structure to bond to
- If a section of pipe is too severely degraded from repeated root pressure over many years, excavation and replacement may be necessary
- If the root system itself poses an ongoing risk to the relined section, such as a very large, established tree directly over the pipe, root barrier installation may be recommended alongside relining
A camera inspection is what determines which category your situation falls into, rather than guessing based on how often the problem has recurred.
Preventing Future Root Intrusion
- Have a CCTV inspection done on any recurring blocked drain, rather than only clearing the immediate blockage
- Consider relining proactively for ageing pipes with known joint gaps near established trees, even before roots become a problem
- Be cautious about planting new trees directly above or near known sewer line paths
- Schedule periodic drain inspections for properties with mature trees close to underground pipework
Stop the Cycle of Recurring Root Blockages
If you've cleared tree roots from the same drain more than once, the roots were never really the problem. The crack or gap they were using to get in is. Pipe relining addresses that underlying damage directly, which is why it's become the standard long-term fix for recurring root intrusion rather than repeatedly cutting roots out of the same weak spot.
Coastal Plumbing Professionals can run a CCTV inspection to confirm whether root damage in your pipes is suitable for relining, and take care of the repair so the problem doesn't keep coming back.
Contact Coastal Plumbing Professionals today to book a drain camera inspection.
Frequently Asked Questions
Will pipe relining stop tree roots for good?
In most cases, yes. Because the liner creates a seamless, jointless surface, it removes the cracks and gaps roots use to get into the pipe, significantly reducing the chance of recurrence.
Do I need to remove the tree causing the root intrusion?
Not necessarily. Relining addresses the pipe's vulnerability directly, so tree removal usually isn't required unless the root system poses an ongoing structural risk to the pipe.
How do I know if roots have already caused serious damage?
A CCTV drain inspection will show whether the pipe is still structurally intact with isolated cracks or joint gaps, or whether root pressure has caused more significant collapse or deformation.
Can relining be done on a pipe that's currently blocked with roots?
The roots need to be cleared first, usually with mechanical cutting or hydro jetting, before the pipe can be cleaned, inspected, and lined.
Is root intrusion covered by insurance?
This varies by policy and the cause of the damage. It's worth checking your specific home insurance product disclosure statement or speaking directly with your insurer.
Resources
- Plumbing work | Queensland Building and Construction Commission
- Spotlight on: AS/NZS 3500 Plumbing and Drainage Standards Series – 2025 Updates
