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Drain guide

Blocked drain
causes and fixes

A Perth homeowner's guide to blocked drain causes and fixes. Most blocked drains in Perth come down to one of six causes: hair and soap scum, food and grease, foreign objects, tree roots, sanitary product build-up, or a damaged pipe. Each one shows up differently, and each needs a different fix. Guessing wrong wastes money on the wrong tool for the job.

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The six causes

The six most common
blocked drain causes

Slow drainage and gurgling usually mean a partial blockage building up. Water backing up in a second fixture, like a toilet bubbling when the shower runs, usually means the blockage sits further down the shared line. See our full blocked drains page for how we diagnose and clear each type.

  1. Hair and soap scum

    Hair binds with soap residue and forms a sticky mass on the inside of pipe walls, usually in bathroom drains. It builds up gradually, so the first sign is slower drainage over several weeks, not a sudden stop.

  2. Fat, grease, and food scraps

    Grease and fat solidify inside pipes as they cool, narrowing the pipe over time. Kitchen drains show this first: a sink that drains fine with hot water but slows once the water cools is a common early sign.

  3. Foreign objects

    Wipes, sanitary products, and small toys don't break down like toilet paper, and they catch on joints or bends inside the pipe. A single flush can cause a sudden, complete blockage rather than a gradual one.

  4. Tree roots

    Tree roots enter drains through small cracks and joints while searching for water. Once inside, they grow into a dense mat that catches debris and slows or stops flow entirely. Recurring blockages in the same spot, especially near established trees, point to roots.

  5. Sanitary and hygiene product build-up

    These don't break down in water and accumulate at pipe bends or where the pipe diameter narrows, often combining with grease to form a solid blockage.

  6. Broken or misaligned pipe

    A cracked, collapsed, or shifted pipe section catches debris passing through and creates a permanent narrow point. Gurgling noises, sewer odour, or a blockage that returns within weeks of clearing usually means the pipe itself needs a camera check.

How we fix each one

Matching the fix to the cause

CauseFixWhy it works
Hair, soap scum, grease Hydro jetting High-pressure water strips the build-up off the pipe wall
Foreign objects Drain snake or hydro jet Physically dislodges or breaks up the object
Tree roots IMS Robotic Cutter, then jetting (tree root removal) Cuts the root mass out before flow is restored
Broken or misaligned pipe CCTV inspection, then repair or reline Confirms the exact damage before we fix the pipe, not just the symptom

Can someone just come and check mine?

Not sure which cause you've got?

I'll run a CCTV camera through the drain, tell you exactly what's causing the blockage, and quote the fix on the spot. No call-out fee to quote. Or call 0499 281 430 now.

Stop repeat blockages, know when to call

Tech in a Plumbed Right hoodie running a CCTV camera at a side-yard pit

Preventing repeat blockages

Stopping blockages before they start

Prevention is mostly about what goes down the drain and how often you check the pipe, not expensive equipment.

  • Use a drain strainer in kitchen and bathroom drains to catch hair and food scraps before they reach the pipe.
  • Never pour grease or oil down the sink. Let it cool and bin it instead.
  • Only flush toilet paper. Wipes, wet or not, don't break down the way toilet paper does.
  • Book a CCTV inspection every year or two if you have established trees near your sewer line, so root intrusion is caught before it blocks the pipe.
CCTV frame of a root mass blocking a drain pipe

When to call a plumber

When a DIY fix isn't enough

A plunger or a basic drain snake can clear a simple, single-fixture blockage. Once water backs up in more than one fixture, or the same drain blocks again within weeks, the cause is usually root intrusion or a damaged pipe, and neither responds to home remedies. Plumbed Right clears blocked drains across Perth using hydro jetting and CCTV cameras, and we diagnose the actual cause before recommending a fix. That means you're paying to solve the problem once, not clearing the same drain every few months.

Blocked drains Perth
Four Plumbed Right staff in hi-vis beside the trailer jetter

Written by

Michael Treble

Owner, Plumbed Right

Plumbed Right is owned and run by Michael Treble. We bring CCTV cameras, a hydro jet and the IMS Robotic Cutter, so we pick the right tool on the day.

  • Perth family owned since 2005
  • Plumbed Right, Lic. PL7390
  • 4.9 on Google, 769 reviews (Oct 2026)

Free on-site quote

Tell us what
it's doing

Plumbed Right provides a free on-site quote before any work starts, so you know the exact price before we touch a tool. No call-out fee, no obligation to book.

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    • Service areaPerth metro, strongest across the northern suburbs (Sorrento, Duncraig, Hillarys, the Joondalup corridor) and the western suburbs. Call to check your street.
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    Questions

    Blocked drain
    questions

    Still unsure? Call and talk to our team, not a call centre.

    Causes and signs

    What are the most common causes of blocked drains?

    Hair and soap scum, grease and food scraps, foreign objects, tree roots, sanitary product build-up, and broken or misaligned pipes account for most blocked drains in Perth homes.

    How do I know if tree roots are blocking my drain?

    Recurring blockages in the same spot, especially near established trees, are the main sign. A CCTV inspection confirms it by showing the roots inside the pipe.

    Fixing it

    Are chemical drain cleaners safe to use?

    They can help with a fresh grease clog but won't clear roots, objects, or a cracked pipe, and repeated use can damage older pipework.

    Can I clear a blocked drain myself?

    A plunger or basic drain snake handles simple, single-fixture blockages. Repeat blockages or water backing up in multiple fixtures need a professional diagnosis.

    How much does it cost to fix a blocked drain?

    It depends on the cause. See our cost to unblock drains guide for what changes the price and the typical Perth range.

    How often should I get my drains checked?

    Every year or two if you have trees near your sewer line, or sooner if you've had a recurring blockage in the same spot.

    Perth drain specialists

    Get the real cause
    diagnosed, then fixed.

    I'll check your drain on camera, tell you the actual cause, and quote the fix before we start. No call-out fee to quote. Call 0499 281 430 or book a free quote.

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