Why Does My Drain Keep Blocking? The Recurring Drain Problem Explained

Christopher Unwin
May 9
4 min read

Updated: 5 days ago

Updated May 2026 — Around The Clock Plumbing Pty Ltd, Oakleigh South.

If your drain keeps blocking — even after another plumber has already cleared it — the problem almost certainly isn't the blockage itself. It's what's causing the blockage that no one has properly diagnosed. This guide explains why recurring blocked drains happen, what genuine diagnostic work looks like, and how to stop the same drain failing every few months.

Why Does the Same Drain Keep Blocking After Jetting?

High-pressure water jetting is an effective way to clear a drain. But jetting removes the symptom — not the cause. If a drain has recurring blockages, something is feeding them: tree root regrowth, a cracked or collapsed pipe section, a joint offset that catches debris, or a pipe pitch that lets solids settle. Until that underlying condition is found and fixed, the drain will block again — sometimes within weeks.

The three most common causes we find in Melbourne south-east and Bayside homes:

Tree root intrusion — roots enter through a joint crack and regrow after cutting. Common in pre-1980 clay and concrete pipes throughout Melbourne's inner south-east.
Pipe damage — a cracked, collapsed or offset section that accumulates debris at the exact same point every time.
Grease and fat build-up — particularly in kitchen drains where lipids congeal on deteriorated or rough pipe walls.

What Real Diagnosis Looks Like: CCTV Drain Inspection

A recurring drain problem requires a CCTV drain camera inspection — a camera fed through the pipe to record the pipe wall, joints and any damage in real time. We use a Ridgid CCTV system with sufficient resolution to identify root mass, fractures, joint separation, pipe belly and collapsed sections even through bends.

Without camera footage, a plumber is guessing. Clearing a recurring drain blind is like treating a fractured bone with paracetamol — it addresses the feeling, not the fracture. Once we have footage, we give you an accurate diagnosis and a permanent fix recommendation, not just another clear.

Permanent Fixes: Pipe Relining vs Targeted Replacement

Once the camera confirms the cause, we discuss your options honestly. For pipe damage or persistent root entry at specific points, CIPP pipe relining is often the right answer: a structural liner is installed inside the existing pipe, sealing cracks and closing root entry points without excavation. Our relining work carries a 35-year structural warranty. Where a section is too severely collapsed to reline, targeted excavation and replacement of that section is the right call — and we'll say so, clearly, rather than selling you a solution that won't last.

Fast arrival → accurate diagnosis → permanent fix. That's the approach that ends a recurring drain problem, rather than turning it into a quarterly expense.

A Real Example: Recurring Sewer — Three Prior Plumbers Had Missed It

In February 2026 we attended a home in Oakleigh where the owner had called three different plumbers over 18 months for a repeatedly backing-up sewer. Each plumber had cleared it and left. When we put our CCTV camera through, we found a 40mm section of completely collapsed pipe roughly 4.5 metres from the access point — invisible to jetting alone, but accumulating solids on every flush. We relined that section in a single visit. The drain hasn't failed since.

When Should You Request a CCTV Drain Inspection?

Request a camera inspection if the same drain has blocked more than once in 12 months; if your previous plumber cleared it but couldn't explain why it blocked; if you're buying a property and want to know the pipe condition before settlement; or if you're in a home built before 1980 with original clay or concrete drain lines. A CCTV inspection is a modest upfront investment that typically saves several call-out fees — and avoids the water damage that accompanies a full sewer backup.

Common Questions About Recurring Blocked Drains

Why does my drain block even after it's been jetted?

Jetting clears the blockage but doesn't fix what's causing it. Root regrowth, pipe damage or a joint offset will produce a new blockage at the same point. A CCTV inspection identifies the underlying cause so it can be permanently addressed.

How long does a CCTV drain inspection take?

Most residential inspections take 30–60 minutes. You receive a verbal briefing on the day and a written summary — useful for insurance claims or property sales.

Is CIPP pipe relining a permanent fix?

CIPP pipe relining carries a 35-year structural warranty. It seals cracks and closes root entry points from the inside, eliminating the recurring failure point without digging up your yard or driveway.

Do you provide a fixed-price quote before starting work?

Yes — we provide a fixed-price quote before any work begins. No hidden call-out fees, no surprises on the invoice. See our transparent pricing guide for detail.

Written and reviewed by Christopher Unwin — founder, Around The Clock Plumbing Pty Ltd, Oakleigh South. BPC Licence #50694, Type A gas, 22 years' experience. National Council member, Master Plumbers Australia & New Zealand.