How Do Tree Roots Get Into Drain Pipes?
Tree roots don’t break into pipes from the outside — they find their way in through existing gaps. Every underground pipe has joints, and over time those joints develop micro-cracks as the soil moves, pipes settle, or rubber seals deteriorate. Even a gap of 1–2mm is enough for a root hair to penetrate.
Once inside, roots encounter warm, moist air and nutrient-rich wastewater. The growth rate accelerates dramatically inside the pipe compared to the surrounding soil. A single root hair that enters a joint in spring can form a significant obstruction by the following summer.
The species most commonly responsible in Melbourne’s western suburbs include:
- Liquid Amber (Liquidambar) — extremely aggressive root systems, very common in Melton and Caroline Springs estates
- Willow trees — notorious for seeking water sources; a single willow can destroy 20 metres of drain
- Peppercorn trees — common in older Bacchus Marsh and Sunbury properties
- Large gum (Eucalyptus) species — particularly in properties with older native plantings
- Bamboo — less common but can be catastrophic due to rhizome spread
What Are the Signs of Tree Roots in Your Drain?
Root intrusion rarely announces itself dramatically — it builds slowly. Watch for:
- Recurring blocked drains that clear temporarily but return within weeks or months
- Slow draining across multiple fixtures simultaneously (bath, basins, laundry)
- Gurgling noises from drains, toilets, or floor wastes after use — caused by air displacement as water forces through a partial blockage
- Sewage odours in the garden or near outdoor drains
- Subsidence or wet patches in the garden or lawn directly above where drain pipes run — indicating a pipe has cracked or collapsed and is leaking wastewater underground
- Repeated blockages in the same location that return despite drain clearing — the classic signature of root intrusion rather than a simple debris blockage
How Are Tree Roots Diagnosed in Drains?
The only way to confirm tree root intrusion and understand its extent is a CCTV drain inspection. A waterproof camera is fed through the drain on a flexible cable, transmitting live video that shows exactly where roots have entered, how far they have grown, what condition the pipe walls are in, and whether the pipe has cracked, displaced, or collapsed at the affected joint.
This information is critical for planning the fix. Root intrusion in a pipe with otherwise good structural integrity is treated very differently from intrusion in a pipe that is cracked or partially collapsed. Getting a CCTV inspection before committing to any drain work saves money and prevents the wrong fix being applied.
Our blocked drain service includes CCTV inspection as standard for any recurrent or unclear blockage. We provide footage and a written report detailing the findings.
How Are Tree Roots Removed From Drains?
There are two main methods for clearing root intrusion:
- High-pressure water jetting: A high-pressure jet of water blasts roots away from the pipe walls and flushes debris downstream. Effective for clearing blockages and restoring flow, but roots will regrow unless the entry point is sealed.
- Root cutting: A spinning mechanical cutter head is fed into the drain to cut roots cleanly at the pipe wall. Used when roots are dense or matted. Again, effective for clearing but not a permanent solution on its own.
Both methods restore flow but neither stops roots from re-entering through the same gap. Within 6–12 months, the roots typically return if the pipe joint is not sealed. That’s why drain clearing should always be followed by an assessment of whether relining or repair is needed.
What Is Pipe Relining and Does It Stop Tree Roots?
Pipe relining is the permanent solution to root intrusion. After roots are cleared, an epoxy-resin liner is inserted into the drain and inflated against the pipe walls. The resin cures hard, forming a new smooth pipe inside the old one — sealing every crack, joint, and gap that roots were using to enter.
Key advantages of relining over traditional pipe replacement:
- No excavation — the liner is installed through existing inspection points, so driveways, gardens, and paths are not dug up
- Faster completion — most residential relining jobs are completed in a single day
- Long-lasting — quality epoxy liners carry a 10–50 year warranty depending on manufacturer and installation
- Root-proof — the seamless resin surface has no joints for roots to enter
Our pipe relining service covers residential sewer and stormwater lines throughout Melton and Melbourne’s west. We use CCTV to confirm the reline has been seated correctly before completing the job.
Does Pipe Relining Work for All Root Intrusion Cases?
Relining is suitable for pipes that are cracked or have open joints but remain structurally intact enough to hold a liner. If the pipe has collapsed or is significantly displaced (offset joints where sections have moved apart), relining may not be possible and excavation with pipe replacement becomes necessary.
This is precisely why a CCTV inspection before quoting any repair is non-negotiable. Quoting relining without seeing the pipe condition first can lead to an installation failure — the liner may not cure correctly or may bridge a void caused by a collapse.
Can Chemical Treatments Kill Roots in Drains?
Various copper sulphate and foaming herbicide products are sold for DIY root treatment. They have limited effectiveness for established root intrusion — they may slow regrowth but won’t clear a blockage caused by matted roots, and they won’t seal the entry point. They are also not safe to use in pipes that drain to stormwater or that have any risk of groundwater contamination.
These products are most useful as a preventive treatment in pipes known to be adjacent to aggressive tree root systems, applied annually as part of a drain maintenance programme. They are not a substitute for professional clearing or relining where root intrusion has already occurred.
Blocked Drains from Tree Roots in Melton and Melbourne’s West
New Image Plumbing & Gas provides full-service drain clearing, CCTV inspection, and pipe relining across Melton, Bacchus Marsh, Caroline Springs, Sunbury, Deer Park, Hoppers Crossing, Werribee, and surrounding suburbs. If you have a recurring blocked drain — especially one that clears temporarily then comes back — root intrusion is the most likely cause.
Read our guide on blocked drains in Melbourne’s west for more context, or check our full sewer and pipe repair options for Melton and Bacchus Marsh. Call 0468 125 098 for same-day service or request a free quote online.
Frequently Asked Questions
How far can tree roots travel to reach a drain?
Tree roots can travel 2–3 times the height of the tree in search of water. A 10-metre gum tree can have roots extending 20–30 metres from the trunk. Never assume a drain problem is unrelated to a tree just because the tree appears far away.
How long does pipe relining last?
Quality epoxy resin liners carry warranties of 10–50 years depending on the product and conditions. The relined pipe is often stronger than the original.
Will removing the tree fix my drain problem?
Removing the tree helps long-term but doesn’t fix the pipe. The roots already inside will decay over months but can cause partial blockages as they do. The pipe still needs clearing and the entry point still needs sealing to prevent future intrusion from neighbouring trees or regrowth from the stump.
What type of pipe is most vulnerable to tree root intrusion?
Older terracotta clay pipes are most vulnerable due to more joints and joint deterioration over time. PVC and concrete pipes in newer estates are more resistant but still susceptible near trees, particularly at inspection points and transitions between pipe types.
How much does pipe relining cost compared to pipe replacement?
Relining typically costs 30–50% less than excavation and replacement once you factor in reinstatement of concrete, paving, and landscaping. The exact comparison depends on depth, access, and length of pipe affected.
