Why Do Blocked Drains Keep Coming Back? The Real Causes (And How to Fix Them for Good)
Recurring blocked drains usually point to a deeper problem. Learn the common causes and how CCTV drain inspections help find a lasting solution.
There’s nothing more frustrating than clearing a blocked drain, only to have it block again a few weeks or months later. While a temporary fix might get the water flowing again, recurring blockages usually indicate a deeper problem within your plumbing system.
At DAS Plumbing & Gas, we regularly help homeowners across the Adelaide Hills, Mount Barker and surrounding South Australian regions diagnose and permanently resolve blocked drains. Using specialised equipment, including CCTV drain inspections, we can identify exactly what’s causing the issue and recommend the most effective long-term solution.
If you’re constantly reaching for the plunger or calling a plumber for the same drain, here’s why it keeps happening.
Why Some Blockages Keep Returning
Not every blocked drain is the same.
A one-off blockage caused by too much toilet paper or food waste is usually simple to clear. However, if the same sink, shower, toilet or stormwater drain continues to block, there’s almost always an underlying issue that hasn’t been properly addressed.
Many temporary drain clearing methods simply remove enough of the blockage for water to pass through. While this restores flow, it doesn’t eliminate the source of the problem.
To permanently fix a recurring blocked drain, it’s important to identify why it’s happening, not just clear the symptoms.
Tree Roots
One of the most common causes of recurring blocked drains throughout the Adelaide Hills is tree root intrusion.
Tree roots naturally seek out moisture, and even the smallest crack or loose joint in an underground pipe can allow roots to enter. Once inside, they continue to grow, trapping toilet paper, grease, food waste and other debris until the pipe becomes blocked.
Signs that tree roots may be the cause include:
Drains that block repeatedly.
Slow-draining toilets or sinks.
Gurgling noises from drains.
Overflowing inspection openings during heavy use.
Blockages that seem to return shortly after being cleared.
Simply cutting away the roots may provide temporary relief, but unless the damaged section of pipe is repaired or replaced, the roots will often grow back.
Fat, Grease and Food Waste
Kitchen sinks are another common source of recurring drain problems.
Many people unknowingly pour cooking oils, fats and grease down the sink while they’re still liquid. As they cool, these substances harden inside the pipework, gradually reducing the pipe’s internal diameter.
Over time, food scraps, coffee grounds and other debris stick to the greasy build-up, eventually creating a stubborn blockage.
To help prevent kitchen drain blockages:
Allow cooking grease to cool before disposing of it in the bin.
Scrape food scraps into the rubbish before washing dishes.
Use sink strainers to catch larger particles.
Avoid pouring oils or fats down the drain.
Good habits can significantly reduce the likelihood of future blockages.
Wet Wipes and Sanitary Products
Despite being marketed as “flushable”, wet wipes are one of the leading causes of blocked sewer drains.
Unlike toilet paper, wet wipes don’t break down quickly in water. Instead, they can become caught on rough sections of pipe, tree roots or existing debris, creating large blockages over time.
Other items that should never be flushed include:
Paper towels
Tissues
Sanitary products
Cotton buds
Nappies
Dental floss
The general rule is simple: if it isn’t toilet paper or human waste, it shouldn’t go down the toilet.
Broken or Collapsed Pipes
Sometimes the blockage isn’t caused by what’s going into the drain at all.
Older properties often have ageing clay or earthenware pipes that can crack, collapse or shift over time due to ground movement, heavy vehicles, tree roots or simple age.
A damaged pipe creates low points, cracks or obstructions that continually catch debris flowing through the drain.
Common warning signs include:
Frequent blockages.
Damp patches in the yard.
Bad smells around the property.
Sinking ground above underground pipes.
Slow drainage throughout multiple fixtures.
Without inspecting the pipe itself, it’s impossible to know whether structural damage is causing the recurring issue.
Why Chemical Drain Cleaners Don’t Solve the Problem
When a drain blocks, it’s tempting to grab a bottle of chemical drain cleaner from the supermarket.
While these products may dissolve some grease or organic matter, they rarely fix the underlying problem.
Chemical cleaners cannot:
Remove tree roots.
Repair broken pipes.
Remove heavy sediment.
Correct collapsed drains.
Identify what’s causing repeated blockages.
In some cases, repeated use of harsh chemicals can even damage older plumbing or make conditions more hazardous for plumbers working on the system later.
If your drain continues to block after using chemical cleaners, it’s usually time for a professional inspection.
How CCTV Drain Inspections Identify the Real Cause
One of the most effective ways to diagnose recurring drain problems is with a CCTV drain inspection.
Using a specialised waterproof camera, we inspect the inside of your drain pipes in real time, allowing us to accurately identify the cause of the blockage without unnecessary digging or guesswork.
A CCTV drain inspection can reveal:
Tree root intrusion
Broken or cracked pipes
Collapsed sections
Grease build-up
Pipe misalignment
Foreign objects
Existing repairs
General pipe condition
Instead of repeatedly clearing the blockage, we can identify exactly what’s happening and recommend the most appropriate long-term solution.
This saves time, reduces repeat call-outs and helps prevent unnecessary repair costs.
Long-Term Repair Options
Once the cause of the blockage has been identified, there are several ways to permanently resolve the problem.
Depending on the condition of your plumbing, solutions may include:
Professional high-pressure drain cleaning.
Mechanical root removal.
Pipe repairs.
Replacement of damaged sections.
Preventative maintenance.
Scheduled CCTV inspections for older drainage systems.
The right solution depends on the underlying cause, which is why proper diagnosis is so important.
At DAS Plumbing & Gas, our goal isn’t just to clear your drain today, we want to prevent it from becoming a problem again in the future.
Don’t Let a Small Blockage Become a Bigger Problem
A slow-draining sink or toilet might seem like a minor inconvenience, but recurring blocked drains rarely fix themselves. Left untreated, they can lead to overflowing drains, unpleasant odours, water damage and much more expensive repairs.
If you’re dealing with blocked drains in the Adelaide Hills, Mount Barker or surrounding areas, DAS Plumbing & Gas can help.
Using professional drain clearing equipment and advanced CCTV drain inspections, we’ll identify the real cause of the blockage and recommend the most effective long-term solution, not just a temporary fix.
Contact DAS Plumbing & Gas today to book a professional drain inspection or speak with our friendly team. We’ll help get your drains flowing properly again and keep them that way.