In this guide
Fast answer
The short answer
A drain that keeps blocking often has an unresolved cause: tree roots entering a failed joint, grease lining the pipe, a low section that holds water, damaged pipework or wipes catching on a rough section. Clearing restores flow, but CCTV can show why the restriction returned before more money is spent on another clear or a repair.
Why a cleared drain blocks again
A blocked drain has two parts — the symptom, which is restricted flow, and the cause that created it. Mechanical equipment or jetting can restore flow, but roots can re-enter through a damaged joint, grease can rebuild on the pipe wall and low sections can retain material. If the same line needs repeated clearing, the history shows that the cause deserves investigation.
CCTV is used after enough flow is restored when the pipe condition, location of the problem or repair plan needs to be recorded. Understanding the cause and next step matters before repeat clearing visits accumulate.
The four causes behind most repeat blockages
Four recurring causes are worth checking: tree roots entering cracks or joints, fats and oils narrowing kitchen waste lines, low sections that retain water and debris, and damaged or displaced pipework. Wipes and other foreign material can then catch on those restrictions.
The symptom alone does not identify which cause is present, so repeat blockages should be investigated from the fixtures that are backing up and access points before a repair is recommended.
How CCTV can show why the drain keeps blocking
A surface symptom does not identify the condition of a buried pipe. Where the line can be made passable, a CCTV inspection can record visible roots, grease, a low section, displaced joint, crack or collapse and show the camera distance at the observation. The footage then supports a the right clearing or repair advice.
Camera travel, visibility and access have limits, while relining must be quoted after the host pipe and repair length are assessed. The next-step explanation should distinguish what was recorded from what still needs confirmation.
When to stop clearing and start fixing
A second blockage in the same drain is a reason to investigate rather than assume another clear will settle it. Call sooner if toilets or sinks gurgle, several fixtures slow together, wastewater odours appear or an outside gully rises. Those symptoms can point further along the private line, but only inspection can confirm the cause.
Blocked Drains Sydney is owner-led by licensed NSW plumber and drainer Scott Johnstone, licence 123739C, with 24-hour contact and urgent help across Sydney. The clear, inspect and repair decision is based on what the inspection shows.
Talk to a Sydney drain specialist
If a drain is blocked now, call Scott and describe what is backing up, where the property is and whether water is still rising. For a non-urgent problem, send the details for a call back.
Request drain helpCommon questions
Why does my drain keep blocking even after a plumber cleared it?
Because clearing restores flow but does not remove the cause. Roots, grease, a sag in the pipe, or a cracked joint are usually still there and rebuild the blockage over weeks or months. A CCTV inspection shows which one it is so it can be properly fixed.
Does a repeat blockage always mean a broken pipe?
No. Grease, wipes, silt, and tree roots can all return without the pipe being broken. That said, recurring blockages near trees often involve roots entering through a cracked joint. A camera inspection confirms whether the pipe itself is damaged or just needs a deeper clean.
Is it worth paying for a CCTV inspection?
It is worth considering after a repeat blockage. A CCTV inspection can record the accessible pipe, show the location of the problem and help decide whether cleaning, repair or relining is justified. What it includes depends on access, camera travel, whether clearing is needed first and which footage, locating or reporting deliverables are required.