Can Tree Roots Damage Underground Pipes, and How Can They Be Removed?

Tree roots can absolutely damage underground pipes and are one of the leading causes of blocked drains across Australia. Roots naturally seek out moisture and nutrients, allowing them to enter tiny cracks, loose pipe joints, or damaged sections of underground drains. Once inside, they continue growing, trapping grease, toilet paper, leaves, and other debris until water flow becomes severely restricted or completely blocked. Professional plumbers remove tree roots using CCTV drain inspections to identify the problem, followed by high-pressure water jetting, mechanical root cutting, pipe relining, or pipe replacement depending on the condition of the pipe. Early diagnosis and professional treatment can often restore the drain before extensive excavation becomes necessary.

Recurring blocked drains caused by tree roots rarely resolve themselves. Although a temporary blockage may clear after heavy rain or a DIY drain treatment, the underlying root intrusion typically remains and continues to grow. Understanding how roots invade drainage systems and how professionals remove them can help homeowners prevent costly plumbing emergencies and long-term underground pipe damage.

If you’re already experiencing recurring blocked drains, understanding the causes is the first step toward a permanent solution. Learn more about MPJ Plumbing’s Blocked Drains service here: https://mpjplumbing.com.au/services/blocked-drains/

Why Tree Roots Cause Blocked Drains

Tree roots are remarkably efficient at finding water.

Underground sewer and stormwater pipes often contain small amounts of moisture around joints or tiny cracks. Even the smallest leak releases moisture into the surrounding soil, attracting nearby roots.

Once a root detects this moisture, it naturally grows toward the source.

After entering the pipe, roots thrive because drains carry nutrient-rich wastewater that provides an ideal growing environment.

Over time, these roots become thicker and denser, eventually filling large sections of the pipe.

Australia’s climate, mature urban trees, and ageing drainage infrastructure make tree root intrusion one of the country’s most common causes of blocked drains.

Older drainage systems are particularly vulnerable because many were built using clay or earthenware pipes that develop gaps and cracks as they age.

How Tree Roots Enter Underground Pipes

Contrary to popular belief, roots usually don’t break healthy pipes.

Instead, they exploit existing weaknesses.

Common entry points include:

• Cracked pipes caused by ground movement
• Loose or deteriorated pipe joints
• Clay and earthenware pipes
• Ageing sewer lines
• Minor fractures caused by wear and tear

What starts as a tiny opening can gradually become much larger.

As roots grow inside the pipe, they apply increasing pressure, widening cracks and separating joints even further.

Eventually, debris catches on the roots, significantly reducing water flow.

Signs Tree Roots Are Causing Blocked Drains

Tree root intrusion often develops slowly.

Recognising the warning signs early can prevent expensive repairs.

Slow-draining sinks

Roots partially restrict water flow, causing sinks, showers, and basins to drain more slowly than usual.

Toilets backing up

When sewer pipes become obstructed, wastewater cannot move freely and may back up into toilets.

Gurgling sounds

Air becomes trapped behind the blockage, creating bubbling or gurgling noises after flushing toilets or emptying sinks.

Bad odours

Organic waste trapped around roots begins decomposing, producing unpleasant sewer smells inside or outside the property.

Frequent blocked drains

If the same drain repeatedly blocks despite clearing attempts, tree roots may be creating an ongoing obstruction.

Water backing up into other fixtures

A blockage in the main sewer line can cause water to appear in showers, baths, or floor drains when another fixture is used.

Overflowing outdoor drains

Stormwater pits and external drains may overflow because water cannot pass through root-filled pipes efficiently.

Wet patches in the yard

Damaged underground pipes may leak continuously, creating persistently damp soil.

Greener-than-normal lawn areas

Leaking wastewater acts as a fertiliser, producing unusually lush patches of grass.

Multiple drains becoming slow

When several fixtures throughout the home experience slow drainage simultaneously, the blockage is often located in the main underground drain rather than an individual fixture.

None of these warning signs should be ignored, as root intrusion generally worsens over time rather than improving on its own.

Why Tree Roots Continue Growing Inside Pipes

Once inside a drainage system, tree roots have everything they need.

They receive:

• A constant supply of water
• Nutrient-rich wastewater
• Protection from weather conditions
• Space to expand

As roots become thicker, they trap additional debris.

Grease, food waste, paper products, leaves, and sediment gradually accumulate around the roots.

The blockage grows larger with every passing month until water can no longer flow through the pipe.

Without treatment, complete blocked drains become increasingly likely.

How Plumbers Diagnose Tree Root Intrusion

Professional diagnosis begins with identifying the exact cause of the blockage rather than relying on guesswork.

Modern plumbers use CCTV drain inspections to examine the inside of underground pipes.

Learn more about CCTV drain inspections here: https://mpjplumbing.com.au/cctv-drain-inspections/

A waterproof camera is fed through the drain, providing a live view of:

• Root intrusion
• Pipe cracks
• Joint separation
• Pipe collapse
• Corrosion
• Debris accumulation

This technology allows plumbers to determine:

• The exact location of the blockage
• The severity of root growth
• Whether the pipe can be repaired
• Whether replacement is necessary

Because the blockage is located accurately, unnecessary excavation is often avoided, reducing disruption to gardens, driveways, and landscaping.

How Tree Roots Are Professionally Removed

The best treatment depends on the condition of the pipe and the extent of the root intrusion.

High-pressure water jetting

High-pressure water jetting uses powerful streams of water to cut through roots while flushing debris from the pipe.

This method is highly effective for:

• Small to moderate root intrusion
• Removing grease buildup
• Cleaning pipe walls
• Restoring normal water flow

Mechanical root cutting

Specialised cutting heads physically slice through thicker root masses inside larger sewer lines.

This method is often used before water jetting to completely clear the obstruction.

Pipe relining

If roots entered through cracks or damaged joints, simply removing them is only a temporary solution.

Pipe relining creates a durable new pipe inside the existing damaged one without extensive excavation.

Learn more about pipe relining here: https://mpjplumbing.com.au/pipe-relining-technology/

Relining seals entry points, preventing roots from returning while extending the life of the drainage system.

Pipe replacement

If the pipe has collapsed or suffered extensive structural damage, replacement may be the safest long-term solution.

Although more invasive, replacement eliminates severely damaged sections that cannot be repaired effectively.

Can Tree Roots Come Back?

Yes.

Removing the roots without repairing the damaged pipe usually allows new roots to return.

The same moisture leak that attracted the original roots continues attracting new growth.

Long-term prevention requires sealing or replacing damaged sections so roots no longer have an entry point.

Routine maintenance also plays an important role.

Scheduled CCTV inspections can identify early root growth before it develops into major blocked drains.

How to Prevent Tree Roots from Causing Blocked Drains

Although mature trees cannot always be removed, several preventative measures can significantly reduce the risk.

Plant trees away from sewer lines

Research mature root spread before planting large trees.

Know where underground pipes are located

Understanding your property’s drainage layout helps avoid planting directly above sewer lines.

Schedule regular CCTV inspections

Periodic inspections detect early root intrusion before severe damage develops.

Repair damaged pipes promptly

Small cracks are much easier and less expensive to repair than collapsed drains.

Respond to early warning signs

Slow drains, unpleasant smells, and recurring blockages should always be investigated promptly.

Preventative maintenance is almost always more affordable than emergency excavation.

When Should Homeowners Call a Professional Plumber?

Professional assistance is recommended if you experience:

• Repeated blocked drains
• Multiple slow-draining fixtures
• Sewage smells
• Outdoor drain overflows
• Water backing up into the home
• Persistent gurgling noises
• Wet patches above underground pipes

Attempting to remove tree roots using chemical drain cleaners or DIY tools rarely addresses the underlying damage and may even worsen pipe deterioration.

Why Early Intervention Saves Money

Ignoring tree root intrusion almost always increases repair costs.

Early diagnosis may prevent:

• Major excavation
• Emergency plumbing call-outs
• Complete pipe replacement
• Water damage
• Landscape restoration
• Structural repairs

A relatively small repair today can prevent a significant plumbing project in the future.

Understanding related plumbing issues also helps homeowners identify problems early. For example, if you’re noticing reduced water flow throughout your home, you may also find our guide on “What causes low water pressure in a home?” helpful, as plumbing symptoms can sometimes occur together.

Supporting Industry Guidance

Australian plumbing systems should be maintained in accordance with recognised industry standards and best practices. Homeowners can find valuable information about plumbing regulations through the Australian Building Codes Board and guidance on water infrastructure and asset management from the Water Services Association of Australia (WSAA). These organisations provide reliable information on maintaining safe, efficient, and compliant plumbing systems.

Conclusion

Tree roots are one of Australia’s most common causes of blocked drains, particularly in older drainage systems where cracks, loose joints, or ageing pipes provide easy entry points. Once inside, roots continue growing, trapping debris and eventually restricting or completely blocking water flow.

The good news is that early diagnosis using CCTV drain inspections, combined with professional root removal, high-pressure water jetting, drain repairs, pipe relining, or pipe replacement when required, can restore your drainage system while preventing more extensive damage.

If you’re experiencing recurring blocked drains, unusual drainage symptoms, or suspect tree roots have invaded your underground pipes, MPJ Plumbing can provide professional CCTV drain inspections, expert root removal, drain repairs, pipe relining, and preventative maintenance to resolve the problem before minor root intrusion becomes a costly plumbing emergency.

Frequently Asked Questions

1. Can tree roots really cause blocked drains?

Yes. Tree roots are one of the leading causes of blocked drains because they enter damaged pipes and trap debris, eventually restricting or completely stopping water flow.

2. How do tree roots find underground pipes?

Roots naturally grow toward moisture. Even tiny leaks around pipe joints or cracks release enough moisture to attract nearby roots.

3. Are older pipes more likely to suffer root intrusion?

Yes. Older clay, earthenware, and ageing sewer pipes are generally more susceptible because they often develop cracks and loose joints over time.

4. Can high-pressure water jetting remove tree roots?

Yes. High-pressure water jetting is highly effective for removing smaller root masses while thoroughly cleaning debris from the inside of the pipe.

5. Will tree roots grow back after removal?

They can if the damaged pipe is not repaired. Sealing cracks through pipe relining or replacing damaged sections helps prevent future root intrusion.

6. Is pipe relining better than replacing pipes?

It depends on the pipe’s condition. Pipe relining is an excellent solution for structurally sound pipes with cracks, while severely collapsed pipes usually require replacement.

7. How often should underground drains be inspected?

Properties with mature trees nearby may benefit from periodic CCTV drain inspections every few years or sooner if recurring blocked drains occur.

8. Can I remove tree roots from drains myself?

DIY methods rarely remove the entire root mass or repair the damaged pipe. Professional equipment provides a safer and more permanent solution.

9. What happens if tree roots are left untreated?

Roots continue growing, causing worsening blockages, pipe damage, wastewater backups, leaks, and potentially expensive excavation or replacement work.

10. When should I call a plumber for blocked drains?

You should contact a plumber if drains repeatedly block, multiple fixtures drain slowly, sewer odours develop, outdoor drains overflow, or wastewater backs up into your home.

Continue reading this series:

• What are the early warning signs of a blocked drain before it becomes a major plumbing problem?
• Why do blocked drains keep coming back, and how can they be permanently fixed?
• How can I prevent blocked drains in my kitchen, bathroom, and outdoor drains?