Tree roots in drain pipes are removed using high-pressure water jetting, mechanical root cutting, or CCTV-guided pipe repair. The roots enter through cracks or loose joints in the pipe, and the only permanent fix is to seal or replace the damaged section so they cannot grow back.
If you have tree roots blocking drains at your property, older homes across South Sydney with original earthenware drainage are the most affected. Mature street trees and established gardens create the perfect conditions for root intrusion. At Steve Bennett Plumbing, we clear and repair root-damaged drains across St George and Sutherland Shire regularly. This guide covers how roots get in, the warning signs, professional removal methods, and how to stop them from coming back.
How Do Tree Roots Get Into Drain Pipes?
Tree roots grow towards moisture. Your drainage pipes carry water and nutrients constantly, making them a target for any root system within range. Roots do not force their way through solid, intact pipes. They enter through existing weak points.
The most common entry points are cracked pipe joints, loose rubber ring seals, hairline fractures in ageing pipes, and poorly glued PVC connections. Earthenware (clay) pipes are the most vulnerable because they are laid in short sections with mortared joints that degrade over decades. Once a fine hair root finds its way through a gap, it grows rapidly inside the pipe where moisture and nutrients are abundant. Within months, a single root can expand into a dense mass that catches debris and restricts flow until the drain blocks completely.
Understanding this matters because killing or cutting the roots inside the pipe is only half the fix. If you do not seal the entry point, the roots grow back within 6 to 12 months. Every effective long-term solution addresses both the roots and the pipe damage that lets them in.
Warning Signs of Tree Roots in Your Drains
The following signs indicate that tree roots may have entered your drainage system:
Drains Slowing Down Gradually
A drain that gets progressively slower over weeks or months is the classic early sign of root intrusion. The roots grow incrementally, catching more debris each day. Unlike a sudden blockage from a foreign object, root blockages develop gradually and worsen steadily.
Gurgling Sounds From Drains or Toilets
Gurgling means air is being trapped by a partial blockage further down the line. When tree roots partially obstruct a pipe, water flowing past the mass creates air pockets that push back through other fixtures. If your toilet gurgles when you run the shower, or a floor drain gurgles when you flush, roots are a strong possibility.
Recurring Blockages That Keep Coming Back
This is the strongest indicator of tree root intrusion. If you clear a blockage and it returns within weeks or months, the roots are growing back because the entry point was never sealed. No amount of chemical treatment or surface clearing will fix a recurring blockage caused by roots.
Foul Odours From Drains
Roots trap waste material inside the pipe. That trapped waste decomposes and releases sewer gas back through the drainage system. A persistent rotten smell from floor drains, shower drains, or outdoor gullies often signals root intrusion combined with waste buildup.
Wet Patches or Sinkholes in the Garden
When roots crack a pipe badly enough, water leaks into the surrounding soil. This creates damp patches, unusually green grass, or soft ground above the pipe run. In severe cases, the soil washes away around the broken pipe and a sinkhole forms.
Multiple Fixtures Affected at Once
If the toilet, shower, and laundry are all draining slowly at the same time, the blockage is in the shared main drain line, not an individual fixture. Tree roots in the main sewer line between the house and the street boundary are the most common cause of simultaneous slow drainage across a property. Book a blocked drain service as soon as you notice multiple fixtures affected.
More: Why Is My Toilet Gurgling? Causes and How to Fix It
Which Pipe Materials Are Most Vulnerable?
Not all pipes are equally at risk. The material your drainage system is made from determines how likely root intrusion is:
Earthenware (Clay) Pipes
Earthenware pipes are the most vulnerable material. They are laid in short sections (typically 300mm to 600mm lengths) with mortared or rubber ring joints. Over 50 to 70 years, the mortar cracks and the rubber perishes, creating gaps at every joint. These pipes are standard in South Sydney homes built before the 1980s. If your home has earthenware drainage, root intrusion is not a question of if but when.
PVC Pipes
PVC pipes are far more resistant to roots because they come in longer lengths with fewer joints. However, they are not immune. Poorly glued joints, cracked sections from ground movement, or damage during construction can create entry points. PVC installed correctly and undamaged can resist roots indefinitely.
Cast Iron Pipes
Cast iron pipes corrode over time, developing pinholes and weakened joints that roots can exploit. These pipes are less common in residential drainage but are found in some older South Sydney properties, particularly for internal waste lines.
Concrete Pipes
Concrete stormwater and sewer pipes are common in older council infrastructure. They crack under ground movement and tree root pressure, allowing intrusion at the fracture points.
What to Do Before Calling a Plumber
A few checks help you confirm whether tree roots are the likely cause before booking a service call:
Check Whether Blockages Are Recurring
Think back over the past 6 to 12 months. If you have cleared the same drain more than once and the blockage returned each time, roots are a strong possibility. A one-off blockage is more likely a foreign object or buildup.
Note Which Fixtures Are Affected
If only one fixture is slow, the blockage may be localised. If multiple fixtures are slow at the same time, the issue is in the main drain line, where roots are most common.
Look at the Trees and Garden Layout
Walk your property and note the position of large trees relative to the drain lines. Drain lines typically run from the house to the front boundary. Any mature tree within 5 to 10 metres of the drain run is a potential source. Certain species are more aggressive than others. Figs, willows, camphor laurels, and liquidambars are notorious for invasive root systems.
Do Not Pour Chemical Drain Cleaners
Chemical drain cleaners do not dissolve tree roots. They may damage the pipe further, particularly if the pipe is already cracked or damaged. Skip the chemicals and call a licensed plumber who can diagnose the actual cause with a camera.
When to Call a Licensed Plumber
Call a plumber if blockages keep recurring, if multiple drains are slow at the same time, if you hear gurgling from drains, if you smell sewer odours inside or outside the house, or if you notice wet patches or sinkholes in the garden. All drainage work in NSW must be carried out by a licensed plumber or drainer. You can verify any plumber’s licence through Service NSW before booking.
How a Licensed Plumber Removes Tree Roots From Drains
When you book a professional, here is what to expect:
CCTV Drain Camera Inspection
A small waterproof camera is fed through the drain to show exactly where the roots have entered, how far they extend, and what condition the pipe is in. This is the essential first step. Without a camera inspection, the plumber is guessing at the location, extent, and cause. Steve Bennett Plumbing uses CCTV drain inspection on every root intrusion job to provide accurate diagnosis and an honest, up-front quote.
High-Pressure Water Jetting
A specialised nozzle delivers water at high pressure into the pipe, cutting through root masses and flushing debris out of the line. Jetting is the most effective method for clearing roots without damaging the pipe. It scours the pipe walls clean and restores full flow. You can read more about our high-pressure drain jetting service.
Mechanical Root Cutting
For dense, established root masses, a mechanical cutter or auger is fed into the pipe to physically cut through the roots. This is often used in combination with jetting. The cutter breaks up the mass, and the jetter flushes it away.
Pipe Relining
Once the roots are cleared, the pipe needs to be sealed to prevent regrowth. Pipe relining is the most effective long-term solution. A resin-coated liner is inserted into the existing pipe and inflated. The resin hardens to form a smooth, jointless new pipe inside the old one. This eliminates every entry point and prevents root regrowth without excavation. All relining work must comply with AS/NZS 3500.
Pipe Replacement
If the pipe is too badly damaged for relining (collapsed sections, severe displacement, or multiple fractures), full or partial pipe replacement is required. This involves excavation, removal of the damaged section, and installation of a new PVC pipe with sealed joints. A licensed plumber lodges the required compliance certificate with NSW Fair Trading after completion.
After tracking down and clearing a difficult tree root blockage for a homeowner in our service area, Steve Bennett Plumbing received this feedback: “Matt did an excellent job of tracking down and sorting out a difficult tree root blockage in our front bathroom.” Jim Bannister.
That is the level of diagnostic precision a root intrusion demands. You can learn more about our team and our 40-year history of solving drainage problems across South Sydney.
Can You Kill Tree Roots in Drain Pipes Yourself?
This is one of the most searched questions about tree root intrusion. Here is an honest assessment of the DIY options:
Copper Sulphate
Copper sulphate crystals flushed down the toilet can kill roots on contact inside the pipe. However, it does not remove the dead root mass (the blockage remains until it decomposes), it is toxic to aquatic life if it enters waterways, and it is not suitable for properties connected to septic systems. It is a temporary measure at best and does not seal the pipe.
Rock Salt
Rock salt dehydrates roots on contact. It is safer for septic systems than copper sulphate. However, like copper sulphate, it does not remove the blockage or seal the entry point. Results are inconsistent and temporary.
Commercial Root Killers
Several commercial products claim to kill tree roots in drain pipes. Most use dichlobenil or copper sulphate as the active ingredient. They may slow root growth temporarily, but none seal the pipe. The roots grow back through the same cracks within months.
Why DIY Methods Are Temporary
Every DIY method treats the symptom (roots inside the pipe) without addressing the cause (cracks or gaps in the pipe wall). The only permanent fix involves clearing the roots professionally and then sealing the pipe through relining or replacement. Spending money on repeated chemical treatments costs more over time than a single professional repair.
More: How to Clear a Drain Blockage
Why Tree Root Intrusion Is So Common in South Sydney
The housing stock, tree canopy, and soil conditions across St George and Sutherland Shire create the ideal environment for root intrusion:
Original Earthenware Drainage in Post-War Homes
Homes across Hurstville, Kogarah, and Peakhurst built between the 1950s and 1970s have original earthenware drainage pipes that are now 50 to 70 years old. The mortared joints on these pipes have been degrading for decades. Every joint is a potential entry point for roots.
Mature Tree-Lined Streets
Mortdale, Oatley, and Carlton have some of the most established street trees in the region. These mature root systems extend well beyond the tree canopy and frequently reach drainage lines running under footpaths and front gardens. I have cleared root-affected drains in these suburbs more than any other area in our service region.
Established Gardens on Larger Blocks
Sans Souci, Sylvania, and Miranda have many larger blocks with mature garden plantings. Fig trees, camphor laurels, and paperbarks are common in these gardens. Their aggressive root systems seek out any available moisture source, and ageing drainage pipes are the easiest target.
Coastal Moisture and Root Activity
Cronulla and Caringbah have higher ambient moisture levels from the coastal environment. This moisture keeps root systems active year-round rather than slowing during drier months. Combined with ageing pipes, this means roots grow faster and re-enter cleared pipes sooner than in drier inland suburbs.
Bushland-Adjacent Properties
Menai, Engadine, and Kirrawee border bushland reserves with extensive native tree cover. Properties backing onto bushland often have root intrusion from trees they do not even own. Council approval may be required before removing or pruning protected native species near drainage lines.
How to Prevent Tree Roots From Coming Back
Once the roots are cleared and the pipe is repaired, these steps reduce the chance of recurrence:
Reline the Pipe After Clearing
Relining creates a jointless, seamless pipe inside the old one. With no cracks or gaps, there is no entry point for roots. This is the single most effective prevention measure. If you are clearing roots for the second or third time, relining should be the priority.
Schedule Annual Drain Inspections
Book an annual CCTV drain inspection to catch early regrowth before it causes a full blockage. Early detection means a quick jetting session rather than an emergency callout. Steve Bennett Plumbing offers scheduled plumbing maintenance visits that include drain camera checks.
Plant Trees Away From Drain Lines
Before planting any new trees, locate your drain lines first. Council-approved sewer diagrams show the drain run on your property. As a rule of thumb, plant trees at least 3 metres from drain lines for small species and 5 to 10 metres for large species. The Australian Government’s water efficiency resources and the WELS water efficiency program provide guidance on water-efficient landscaping that reduces moisture around pipes.
Install Root Barriers
Physical root barriers made from high-density polyethylene can be installed between a tree and a drain line. They redirect root growth downward and away from the pipe. This is a practical option when removing a mature tree is not desirable or permitted.
Avoid Flushing Grease and Debris
Roots catch debris to form blockages. Reducing the amount of grease, food scraps, and non-flushable items entering your drains slows the rate at which root masses grow into full blockages. The cleaner the pipe, the longer it takes for a small root entry to become a problem.
More: Why Your Drains Smell and How to Get Rid of the Odour
Areas We Service
Steve Bennett Plumbing serves homeowners across the St George and Sutherland Shire regions. Our service area includes Hurstville, Kogarah, Peakhurst, Sans Souci, Mortdale, Oatley, Carlton, Miranda, Cronulla, Engadine, Caringbah, Kirrawee, Sylvania, Menai, and Gymea.
Clear Tree Roots From Your Drains for Good in Sydney
If your drains keep blocking and you suspect tree roots, do not waste money on temporary fixes. A cleared pipe without a sealed entry point will block again within months. Professional jetting combined with pipe relining stops roots permanently and protects your drainage system for decades.
Call Steve Bennett Plumbing today on 02 9538 7864 or reach our emergency line on 0413 158 600. With over 40 years of drainage experience across St George and Sutherland Shire, we have cleared more root-affected drains in South Sydney than we can count. Every callout includes a $0 call-out fee, a fixed-price quote, and same-day service where possible. Our lifetime labour warranty backs every repair. We respond to emergencies when a root blockage causes a sewer backup or overflow.
Frequently Asked Questions
How do I get rid of tree roots in drain pipes?
Tree roots are removed using high-pressure water jetting, mechanical cutting, or a combination of both. A CCTV camera locates the roots first. After clearing, the pipe should be relined or replaced to seal the entry point and prevent regrowth.
How do I dissolve tree roots in drain pipes?
Copper sulphate and commercial root killers can kill roots on contact, but they do not dissolve or remove the root mass from the pipe. The blockage remains until the dead roots decompose. These products are temporary and do not seal the pipe against regrowth.
Can tree roots damage PVC pipes?
PVC pipes are far more resistant to root intrusion than earthenware or concrete. However, poorly glued joints, cracks from ground movement, or construction damage can create entry points. Correctly installed and undamaged PVC resists roots indefinitely.
How do I know if tree roots are in my drains?
Warning signs include gradually slowing drains, gurgling sounds from toilets or drains, recurring blockages that return after clearing, foul odours from drains, wet patches in the garden, and sinkholes above the pipe run. A CCTV drain camera provides definitive confirmation.
How often do tree roots grow back in drain pipes?
Without sealing the pipe, roots typically regrow within 6 to 12 months after clearing. The speed depends on the tree species, the size of the entry point, and soil moisture. Pipe relining prevents regrowth permanently by eliminating all entry points.
Should I remove a tree that is damaging my drains?
Not necessarily. Tree removal is expensive and may require council approval for protected species. In most cases, the pipe can be relined or replaced without removing the tree. Root barriers can also redirect growth away from the drain line. A licensed plumber can advise on the most cost-effective solution.
