Why Does My Drain Keep Blocking? Common Causes of Recurring Blocked Drains
If you’ve had a blocked drain cleared only for the same problem to return a few weeks or months later, there may be more going on than a simple blockage.
Recurring blocked drains can be caused by tree roots, damaged pipes, grease and waste build-up, foreign objects or problems deeper within your drainage system. While clearing the blockage might get the water flowing again, it doesn’t always address why the drain keeps blocking in the first place.
At Blast Plumbing & Roofing, we provide blocked drain services, CCTV drain inspections and high-pressure drain jetting across Brisbane, helping identify and clear drainage problems rather than relying on guesswork.
So, why does your drain keep blocking? Let’s look at some of the most common causes and what you can do about them.
Why Does My Drain Keep Blocking?
A drain becomes blocked when something prevents water and waste from flowing freely through the pipe.
Sometimes the cause is straightforward. There might be too much waste in the pipe or something may have been flushed that shouldn’t have been.
However, if the same drain keeps blocking, there may be an underlying issue that needs further investigation.
Some of the most common causes of recurring blocked drains include:
Tree root intrusion
Grease and waste build-up
Damaged or cracked pipes
Foreign objects
Misaligned or deteriorating pipework
Stormwater debris
A blockage that wasn’t completely cleared
The challenge is that most drainage pipes are underground or concealed, making it difficult to know exactly what is happening without the right equipment.
1. Tree Roots Growing Into Your Drains
Tree roots can be a major problem for underground drainage systems.
Roots naturally seek out moisture and can enter drainage pipes through small cracks, damaged joints or other openings. Once inside, the roots can continue growing and begin catching toilet paper, waste and debris as it passes through the pipe.
Eventually, this can restrict water flow and cause the drain to block.
You might have the immediate blockage cleared and think the problem has been fixed, but if root intrusion remains, the drain may block again.
A CCTV drain inspection can help identify whether tree roots are present and show where they are entering the accessible pipework.
2. Grease, Fat And Waste Build-Up
Kitchen drains regularly deal with food waste, oils, grease and other materials.
While hot grease may initially flow down the sink, it can cool and stick to the inside of drainage pipes. More waste can then attach to this build-up, gradually narrowing the space available for water to flow.
You may initially notice that your kitchen sink is taking longer to empty before the problem develops into a more significant blockage.
Avoid pouring fats, oils and grease down your kitchen sink and use a sink strainer to catch food scraps where practical.
3. Damaged Or Cracked Drainage Pipes
Sometimes the blockage isn't the main problem. The condition of the pipe itself can be contributing to it.
Cracks, damaged joints, displaced sections or other pipe problems can interfere with normal drainage and create areas where waste and debris become caught.
This can lead to the same section of drain repeatedly blocking.
Because underground pipes can't easily be inspected from the surface, a drain camera can be useful for identifying visible damage and determining whether the pipe itself may be contributing to the problem.
4. Foreign Objects In The Drain
Toilets and drains are designed to handle specific types of waste.
Wipes, sanitary products, paper towel and other household items can cause problems when flushed or washed into the drainage system.
Foreign objects may become lodged inside a pipe or catch other waste as it passes, eventually creating a larger obstruction.
If an object has become stuck deeper within the drainage system, a CCTV drain camera may help locate the problem.
5. The Blockage Wasn't Completely Cleared
Sometimes a drain starts flowing again even though some of the obstruction remains.
Enough material may have been removed to allow water through, but remaining grease, roots, waste or debris can begin collecting more material.
Eventually, the drain becomes restricted again.
This is where high-pressure drain jetting can be useful in appropriate situations.
Rather than simply creating a pathway through an obstruction, professional drain jetting uses high-pressure water to clear stubborn material and build-up from inside the drainage pipe.
6. Stormwater Drain Blockages
Recurring drainage problems aren't limited to toilets, kitchens and bathrooms.
Stormwater drains can become blocked by leaves, soil, sticks and other outdoor debris. Tree roots and damaged underground pipework can also contribute to stormwater drainage problems.
You might notice:
Water pooling around your property
Stormwater drains overflowing
Water draining slowly after rain
Drains backing up during heavy rainfall
Recurring flooding in the same area
With Brisbane's periods of heavy rain and storms, properly functioning stormwater drainage is particularly important.
If a stormwater drain repeatedly backs up, a CCTV inspection can help investigate accessible pipework and locate potential blockages or visible damage.
7. Misaligned Or Deteriorating Pipework
Drainage pipes need a clear pathway for water and waste to move through the system.
If sections of pipework have moved, deteriorated or become misaligned, waste may be more likely to catch in the affected area.
The result can be a blockage that keeps returning even after the drain has been cleared.
If there isn't an obvious reason for recurring drainage problems, investigating the condition of the pipework may help determine what's happening.
What Are The Signs Of A Blocked Drain?
A completely blocked toilet or overflowing drain is difficult to miss, but drainage problems often provide warning signs before reaching that stage.
Keep an eye out for:
Slow Draining Water
Sinks, showers or baths taking longer than normal to empty can indicate a partial blockage.
Gurgling Drains Or Toilets
Gurgling sounds can occur when water and air aren't moving through the drainage system normally.
Unpleasant Drain Smells
Persistent smells coming from sinks, showers or other drains may indicate waste or other material accumulating within the system.
Water Backing Up
Water coming back through toilets, sinks, showers or floor drains is a clear sign that something needs attention.
Multiple Drains Having Problems
If several fixtures begin draining slowly or blocking at around the same time, the issue may be further along the drainage system.
The Same Drain Keeps Blocking
This is one of the biggest indications that further investigation may be worthwhile.
If you've already had the drain cleared and the problem keeps returning, there could be an underlying cause that hasn't yet been addressed.
Why Does My Drain Keep Blocking After Being Cleared?
If the drain has already been cleared, it's reasonable to wonder why you're dealing with the same problem again.
Clearing a blockage and identifying its underlying cause are not necessarily the same thing.
For example, a plumber may restore flow through a drain affected by tree roots. But if roots are entering through damaged pipework, the problem can potentially return.
Likewise, damaged or displaced pipework may continue catching waste even after the existing obstruction has been removed.
When a drain repeatedly blocks, the question becomes less about how to unblock it and more about why it keeps happening.
That's where further investigation can be valuable.
How Can A CCTV Drain Inspection Find The Problem?
A CCTV drain inspection involves feeding a specialised waterproof camera through accessible drainage pipework.
Instead of guessing what may be happening underground, the camera gives the plumber a view inside the drain.
Depending on the condition and accessibility of the pipe, a CCTV drain inspection can help identify:
Tree root intrusion
Stubborn blockages
Built-up waste and debris
Cracked or damaged pipework
Displaced joints
Foreign objects
Other visible drainage problems
This can be particularly helpful when you're dealing with a drain that keeps blocking despite previously being cleared.
Blast Plumbing & Roofing provides CCTV drain inspections across Brisbane, including Brisbane's northside, Logan and surrounding areas.
CCTV Drain Inspection Vs High-Pressure Drain Jetting
CCTV drain inspections and high-pressure drain jetting perform two different jobs, but they can work together.
A CCTV drain camera helps investigate the problem.
A high-pressure drain jetter helps clear appropriate blockages.
Once the location and nature of a blockage are understood, high-pressure water can be used where suitable to clear materials such as grease, sludge, debris, waste build-up and some tree root intrusion.
The CCTV equipment can also be used to inspect accessible sections of the drain and determine whether there appears to be an underlying issue contributing to the blockage.
For recurring blocked drains, this can provide a much clearer picture than simply clearing the drain without knowing why it became blocked.
How Can I Help Prevent Blocked Drains?
Not every blockage is preventable, particularly when damaged underground pipes or tree roots are involved. However, a few simple habits can reduce avoidable drainage problems.
Avoid pouring fats, oils and grease down kitchen sinks. Keep wipes, sanitary products, paper towel and household waste out of toilets. Use sink strainers where practical and pay attention when drains suddenly begin emptying more slowly.
Most importantly, don't ignore a blockage that keeps returning.
Recurring problems can indicate that something deeper within the drainage system needs attention.
When Should I Call A Plumber For A Blocked Drain?
If a simple blockage doesn't clear, keeps returning or is affecting multiple drains, it's worth having the problem professionally assessed.
You should also consider calling a plumber if you notice water backing up, persistent gurgling, unpleasant smells or stormwater repeatedly overflowing around your property.
For recurring problems, a CCTV drain inspection may be recommended to help identify what is happening inside the drainage system before deciding on the appropriate next step.
Blocked Drain & CCTV Drain Inspections Brisbane
If your drain keeps blocking, don't keep treating the same problem without finding out why it's happening.
Blast Plumbing & Roofing provides professional blocked drain services, CCTV drain inspections and high-pressure drain jetting across Brisbane.
Using specialised drain camera equipment, we can investigate accessible drainage pipes, locate stubborn blockages and identify visible problems such as tree root intrusion and damaged pipework.
Where appropriate, our commercial high-pressure drain jetter can then be used to clear stubborn blockages and restore proper flow.
We service Albany Creek, Aspley, Chermside, North Lakes, Caboolture, Brisbane's northside, Logan and surrounding areas.
If your drain keeps blocking, contact Blast Plumbing & Roofing to organise an inspection.
