How to Prevent Blocked Drains at Home

What Causes Most Blocked Drains?

The vast majority of blocked drains are caused by gradual buildup rather than a single event. Hair, soap scum, grease, food scraps, and mineral deposits accumulate over time until flow is restricted enough to cause a problem. In older Melbourne properties, tree root intrusion into clay or cast iron pipes is also very common — roots are drawn to the moisture around pipe joints and can cause significant blockages over several years.

Outside, stormwater drains are often blocked by leaves, dirt, and debris — particularly after Melbourne's autumn and after storm events. These blockages can cause water to back up and damage foundations or landscaping if left untreated.

Kitchen Drains

Grease and cooking oil are the primary cause of kitchen drain blockages. Even small amounts poured down the sink regularly will coat the inside of drain pipes and collect food particles over time, eventually forming a solid plug. The best approach is to pour cooking fats into a container and dispose of them in the bin once solidified.

Food scraps are another major contributor. Even with a garbage disposal unit, fibrous vegetables, coffee grounds, and eggshells should go in the bin rather than the drain. A simple drain strainer over the kitchen sink catches most solid debris before it enters the pipe.

• Never pour cooking oil or fat down the sink — bin it once cooled
• Use a sink strainer to catch food particles
• Run hot water for 30 seconds after washing dishes to flush the drain
• Avoid putting coffee grounds, eggshells, or fibrous vegetables down the drain

Bathroom Drains

Hair is the number one cause of shower and bath drain blockages. A hair catcher or drain screen is one of the cheapest and most effective preventive measures available — they cost a few dollars and can be rinsed clean every week. Without one, hair combines with soap scum and forms a dense mat inside the drain that becomes progressively harder to clear.

Soap buildup is the second major bathroom drain issue. Soap scum forms from the interaction of soap with hard water minerals and sticks to pipe walls. Flushing drains with hot water regularly and using liquid soap rather than bar soap reduces buildup significantly.

Toilet Blockages

Toilets are designed to handle human waste and toilet paper — nothing else. Wet wipes are the single biggest cause of sewer blockages in Melbourne, even those labelled "flushable." They do not break down in the same way as toilet paper and accumulate in pipes and at pump stations. Paper towels, cotton pads, sanitary products, and dental floss should all go in the bin.

Outdoor and Stormwater Drains

Keeping outdoor drains clear requires regular maintenance rather than any particular product. Clear leaves and debris from drain grates after rain and during autumn, and trim overhanging trees near drain lines where possible. If you have an older property with clay or cast iron pipes, periodic CCTV drain inspection is worthwhile — tree root intrusion is much cheaper to address early than after a full blockage.

• Clear leaves from stormwater grates after rain
• Trim trees whose roots might reach drain lines
• Get CCTV inspection on older clay or cast iron pipes every few years
• Check downpipe connections are clear before wet season

When to Call a Plumber

If a plunger and hot water don't clear a blocked drain within a few minutes, stop and call a plumber. Over-the-counter chemical drain cleaners can corrode older pipes and often don't fully dissolve hair-based blockages — they may temporarily restore flow while leaving the core of the blockage in place. A plumber with a drain snake or high-pressure jetter will clear the blockage completely and can use a CCTV camera to check for underlying issues like root intrusion or pipe damage.