Overview of the Toilet Blocking Issue

At a property on Warrigal Road in Oakleigh VIC 3166, our team at Your Choice Plumbers was called out after the owner reported a toilet that kept blocking repeatedly. As an experienced plumber Oakleigh, we often find that when the same toilet keeps blocking every few months, there is usually a bigger issue involved than just a one-off clog.

The toilet had already been blocking at roughly six-month intervals, and this time the owner wanted not only to have it cleared, but to fully investigate why the problem kept returning.

This is exactly the type of situation where homeowners start asking, “why does my toilet keep blocking?” or “why does only one toilet keep clogging when the rest of the drains are fine?” In this case, the fact that only the toilet was affected was an important clue that the issue was likely isolated to the toilet branch drain rather than the main sewer line.

Initial Unblocking and First Checks

Our first step was to restore function to the toilet.

We used a Rothenberger Ropump Super Plus Force Pump to clear the blockage and get the toilet operational again, then cleaned the area thoroughly before moving on to the investigation stage.

Once the toilet was flushing again, we carried out the standard internal checks that should always be done before assuming the issue is further down the drain line.

We:

  • opened the cistern and checked the internal water level against the manufacturer’s water level mark
  • confirmed the cistern water level was set correctly
  • tested both dual flush buttons
  • confirmed both flush volumes were operating as intended

This allowed us to rule out weak flushing performance as the cause of the repeated blockages.

Why We Focused on the Toilet Branch Drain

We then asked the owner whether there had ever been any full sewer back-ups elsewhere in the property or whether the issue was isolated to the toilet.

The owner confirmed that the rest of the drains were fine and that there had never been a full sewer surcharge.

That was a key diagnostic turning point.

Because the problem was isolated to one toilet only, the most logical next step was to inspect the toilet’s individual branch drain rather than treat it as a general sewer blockage.

This is an important distinction, because many homeowners assume repeated toilet blockages always mean there is a major sewer problem, when in reality the fault is often hidden on the short section of drain serving that single toilet.

CCTV Inspection of the Toilet Branch Drain

To investigate further, we located an accessible inspection opening on the toilet branch drain outside the property.

This was a 100mm UPVC drain with a screwed inspection cap, running up from the ground, through the external brick wall, and connecting directly to the toilet line.

That access point gave us exactly what we needed.

We inserted our Ridgid SeeSnake drain camera into the toilet branch drain and carried out a full CCTV inspection. The camera quickly identified visible tree roots entering the line at a 100mm UPVC 90-degree bend on the toilet branch connection.

This immediately confirmed that the recurring blockages were not random — there was a structural defect allowing roots to enter and catch waste over time.

Root Removal and Secondary CCTV Confirmation

Once the roots were identified, we used a hydro jet drain machine fitted with a Root Ranger tree root cutting head to fully clear the obstruction.

After the roots had been cut and removed, we ran the CCTV camera through the branch drain again.

This second inspection showed the underlying cause clearly:

  • the 90-degree UPVC bend had cracked
  • the crack was allowing tree roots to grow into the pipe
  • over time, those roots would trap paper and waste
  • this explained why the toilet kept blocking every few months

We kept the owner informed throughout the process and showed the findings live on the drain camera monitor so they could clearly understand the problem and the reason the blockages kept returning.

Why the Drain Bend Likely Failed

We explained to the owner that this type of problem is more commonly found in older terracotta drains, where root intrusion is expected over time.

By contrast, cracked UPVC bends are less common, which is why this case stood out.

Based on our experience, when we later excavate and repair this type of problem, we often find that the root cause is not just age or root pressure, but an installation compliance issue.

In this case, the most likely cause of the cracked bend was inadequate support beneath the fitting.

Under AS/NZS 3500.2:2021 Clause 4.4.4.1(c), a minimum 100mm concrete support pad is required beneath this type of bend. That support is critical because it:

  • reduces movement in the drain
  • protects the fitting from long-term settlement stress
  • helps prevent breakage when drain cleaning equipment is used

Because the bend was plastic, the lack of proper support likely made it more vulnerable to cracking over time.

Repair Recommendation and Final Outcome

Once the defect had been confirmed, we quoted to replace the cracked bend and successfully carried out the repair.

This gave the owner a permanent solution instead of another short-term unblock.

The owner was relieved to finally understand why the toilet had been blocking so frequently and even more relieved to know the problem had been properly investigated and fixed rather than simply cleared again.

Compliance & Prevention Insight

This case highlights why repeated toilet blockages should never be treated as “just another blockage.”

When a toilet keeps blocking at regular intervals, there is usually an underlying issue that needs to be identified — whether it is weak flushing performance, partial obstruction, root intrusion, or a damaged drain fitting.

It also shows why CCTV drain inspections are so valuable. Without camera confirmation, the roots may have been cleared temporarily, but the cracked bend would have remained and the problem would have returned.

Compliance with Australian Standards

All work carried out by Your Choice Plumbers is completed in accordance with the relevant requirements of AS/NZS 3500.2:2021, ensuring drainage systems are installed and repaired to proper standards.

In simple terms, this means your drainage system is repaired correctly, supported properly, and less likely to fail again in the future.

Our Home Plumbing Experts Approach

As part of our Home Plumbing Experts approach, we focus on both repair and prevention.

We offer a Complimentary Property Protection Audit as part of our service, assessing key areas like water pressure, hot water temperature, and flexible hoses — helping homeowners stay ahead of potential plumbing failures and avoid unexpected water damage.

👉 Find out more about our blocked toilet Melbourne services.