Melbourne’s leafier suburbs are full of established gardens, street trees, and decades-old plantings, and while they make a property look great, they are also one of the most common causes of a Blocked Drain Melbourne homeowners deal with. Tree roots in drain pipes are especially common in older suburbs where clay or earthenware sewer lines were laid alongside trees that have had thirty, fifty, or even eighty years to grow. If you have noticed slow drains, gurgling toilets, or a suspiciously green patch of lawn, roots inside your pipes could well be the reason, and clearing the blockage without addressing the roots themselves rarely solves the problem for good.
How Do Tree Roots Actually Get Inside Drain Pipes?
Tree roots do not force their way through solid, healthy pipe. They are drawn to the moisture, warmth, and nutrients inside a sewer or stormwater line, and they exploit weaknesses that already exist, tiny gaps at pipe joints, hairline cracks, or slightly misaligned sections. Once a fine root finds its way through one of these openings, it thickens over time, and as it grows, it widens the gap it entered through, allowing more roots to follow. What starts as an almost invisible intrusion can turn into a dense root mass filling a significant portion of the pipe within a year or two.
Can Roots Break a Healthy Pipe?
Generally, no. Roots exploit existing faults rather than creating damage in an otherwise sound pipe, which is an important distinction. That said, once roots are established inside a pipe, their continued growth can widen cracks, push joints further apart, and put pressure on the surrounding pipe material, turning a minor fault into a much larger structural problem over time. So while roots are rarely the original cause of pipe damage, they are very often the reason a small, unnoticed fault turns into a major blockage or even a partial collapse.
Are Clay and Terracotta Pipes More Vulnerable?
Yes, significantly. Many established Melbourne properties, particularly in the inner and older middle-ring suburbs, still have original clay or earthenware sewer pipes, sometimes seventy years old or more. These pipes were typically laid in short sections joined together, and over decades, the mortar or seals at each joint can degrade, shrink, or crack, creating exactly the kind of small opening roots are drawn to. Modern PVC and poly pipes are manufactured in much longer continuous lengths with fewer joints, and those joints are sealed in ways that are far more resistant to root intrusion. If your home still has its original clay drainage system, root intrusion is one of the most likely causes of any recurring blockage.
What Are the Signs of Tree Roots in Drains?
Several warning signs tend to show up before a full blockage occurs, and catching them early can save you from a much bigger repair down the track:
- Slow-draining sinks, showers, or toilets that gradually get worse rather than blocking suddenly
- Gurgling sounds from drains or toilets, particularly when other fixtures are used
- Recurring blockages in the same location, especially after the drain has already been cleared once
- Unusually lush, green, or fast-growing grass in a specific strip of the lawn, often tracking the line of the underground pipe
- A foul sewage smell in the yard, particularly near where the pipe runs
- Visible depressions or soft spots in the ground above the pipe
If your property has mature trees near the sewer or stormwater line and you are noticing any of these signs, it is worth having the drain properly inspected rather than waiting for a full blockage to develop.
Can CCTV Identify Tree Roots?
Yes, and this is by far the most reliable way to confirm root intrusion rather than guessing based on symptoms alone. A CCTV drain inspection feeds a waterproof camera directly through the pipe, showing the exact point where roots have entered, how extensive the growth is, and whether the surrounding pipe shows signs of cracking, misalignment, or wear. This matters because it tells a plumber not just that roots are present, but precisely where the entry point is, which is essential information for deciding whether root cutting alone will fix the problem or whether a repair is also needed at that location.
Can Hydro Jetting Remove Tree Roots?
High-pressure hydro jetting is one of the most effective methods for clearing root growth from inside a pipe. Unlike a standard drain auger, which tends to punch a narrow channel through whatever is blocking the pipe, a hydro jet uses a powerful, rotating stream of water to strip root material from the entire internal surface of the pipe. This clears the immediate blockage more thoroughly and leaves a cleaner pipe wall, which slows how quickly new root growth can re-establish itself. Jetting does not repair the entry point where roots got in, so it is often paired with a CCTV inspection to check whether further work is needed at that specific spot.
What Is Drain Root Cutting?
Drain root cutting uses a specialised mechanical cutting head, fed through the pipe on a cable, to physically shred and remove dense root masses that hydro jetting alone may not fully clear. It is typically used for more established root growth where the roots have thickened significantly inside the pipe. Root cutting restores flow effectively, but like jetting, it addresses the growth rather than the underlying entry point, so it is best understood as one part of a complete fix rather than a permanent solution on its own.
Will Roots Grow Back After They’re Removed?
In most cases, yes, unless the entry point is also addressed. Cutting or jetting removes the root material currently inside the pipe, but if the crack, gap, or joint the roots originally grew through is left unrepaired, nearby tree roots will typically find their way back through that same opening within months. This is the single biggest reason homeowners find themselves calling a plumber for the same blocked drain every six to twelve months. Permanently stopping root regrowth means sealing or repairing the entry point itself, not just clearing what has grown through it.
Do Chemicals Kill Roots Permanently?
Chemical root treatments, typically copper sulphate or foaming herbicide products applied through the drain after clearing, can help slow future root growth by making the immediate area inside the pipe less hospitable. They are a reasonable supporting measure in some cases, but they are not a permanent fix on their own, and they do nothing to repair a cracked or gapped pipe. Chemical treatments work best as an added layer of protection alongside a proper repair, not as a substitute for one.
When Should a Damaged Pipe Be Relined?
Once a CCTV inspection confirms that roots are entering through a cracked or gapped section of pipe rather than an isolated, easily sealed joint, pipe relining is usually the most effective long-term fix. Relining involves inserting a new pipe liner inside the existing damaged pipe, sealing off root entry points and cracks without the need to excavate the yard. It restores a smooth internal surface that is far more resistant to future root intrusion, and it is generally the recommended option once a section of clay or earthenware pipe has been repeatedly compromised by root growth.
When Does the Pipe Need Replacing Instead?
Relining works well when the existing pipe still has enough structural integrity to support a new liner. If a section of pipe has partially collapsed, is severely misaligned, or has been damaged extensively enough that relining is not viable, full excavation and pipe replacement becomes necessary. This is a larger job, but it is sometimes the only reliable option for older clay pipe runs that have suffered significant root damage over many years, particularly where roots have caused the pipe to shift out of alignment rather than simply cracking through a joint.
Stopping the Cycle for Good
Tree roots in drain pipes are rarely a one-off problem. If a blockage caused by roots has been cleared without the entry point being repaired, the roots will very likely return, and each repeat call-out costs more over time than addressing the underlying issue once. A CCTV inspection is the starting point for any property with mature trees near its sewer or stormwater lines, since it confirms exactly where the roots are entering and whether jetting, root cutting, relining, or replacement is the right next step.
If you are dealing with recurring blockages and suspect tree roots are behind them, our team can carry out a full CCTV drain inspection to confirm the cause and recommend a permanent fix, whether that is root cutting, relining, or a repair. Call King and Sons Plumbing on 03 9993 7122, available 24 hours a day, 7 days a week, across Melbourne.
