Guide to Clearing Blocked Drains: DIY Tips and Professional Advice

Blocked drains don’t usually come out of nowhere. There are always hints.

A slow-draining sink is often the first sign. Water that pools and takes longer than usual to drain signals early obstruction.

Next is gurgling. If water drains and you hear bubbling or sucking noises, air is being displaced around a blockage.

Bad smells? That’s waste sitting in the pipe.

Toilets may struggle to flush properly or make odd noises when other fixtures are used. In worse cases, water might back up in a floor drain after using the washing machine.

Take these signs seriously. Early action is easier and cheaper than dealing with an overflow.

Confirming It’s a Blocked Drain (and Not Something Else)

It’s easy to assume any drainage issue means a blockage. But that’s not always true.

Start with a basic check:

• Multiple fixtures slow? Problem might be deeper in the main line.
• Just one sink or shower affected? Likely localised to that fixture.
• Water backing up in another drain when using the washing machine or dishwasher? That’s a tell-tale sign of a shared pipe blockage.

Don’t forget venting. A blocked plumbing vent can mimic drainage issues but is a different problem altogether.

Use a flashlight and remove the drain cover. Hair and scum might be visible near the top. If water clears slowly but eventually drains, it’s likely partial—not a full blockage yet.

If water drains away completely when the system is unused for a while, it may be a soft clog that can be cleared with home methods.

What’s Causing the Blockage?

Some blockages build slowly. Others happen after one wrong item goes down.

Inside the Home

• Hair and Soap Scum: Bathroom sinks, showers, and tubs are prone to hair traps. Mixed with soap and conditioner, it clumps and hardens just below the drain cover. Even a small amount builds up over time.
• Grease and Food Scraps: Hot oil looks harmless when poured down the sink. But once it cools, it solidifies. That fat grabs crumbs, coffee grounds, and more. Soon, the pipe narrows like clogged arteries.
• Wipes, Tissues, and Foreign Items: Toilets are only made for two things. Tissues, wipes (even the “flushable” ones), dental floss, and cotton buds cause instant issues. Children also drop items in toilets out of curiosity.

Outside the Home

• Tree Roots: Small cracks in older pipes let roots in. The roots grow fast, attracted to the moisture. They form a tight mat that blocks everything.
• Leaves, Mud, and Silt: Outdoor drains fill with organic matter. In autumn, leaves settle fast. After storms, mud and small debris flood into grates and pipes. Without regular clearing, these drains clog badly.

Home Fixes to Try First

Some problems can be sorted without tools. Others need a little more effort.

Boiling Water Flush

Works well for grease-based blockages in kitchen sinks.

Boil a full kettle. Pour it slowly down the affected drain in stages. Give it time to work between pours.

Avoid if your home uses PVC piping. Extreme heat can soften joints and fittings.

Bicarb Soda and Vinegar

Natural and inexpensive.

Pour half a cup of bicarb soda down the drain. Follow it with one cup of white vinegar. Immediately cover the drain opening with a plug or cloth.

Let it sit for 15 minutes. You’ll hear fizzing as it reacts. Flush with hot water once the reaction slows.

Best for minor buildup—not heavy clogs.

The Plunger Method

Use the right plunger. Flat ones suit sinks. Flange plungers are better for toilets.

Add water if the fixture is empty. Cover the drain completely with the plunger head. Push down gently, then pull back hard. Do it 10–15 times.

Breaks up soft clogs and creates pressure to dislodge partial blockages.

Drain Snakes and Hair Tools

Hair removal tools are cheap and effective in showers and basins. Insert, twist, and pull up hair clumps.

For deeper clogs, a manual drain snake can reach further. Feed the coil in slowly. When you hit resistance, rotate the handle to latch onto debris. Pull it back gently.

These tools are ideal for soap scum and hair, but less effective against grease or roots.

Chemical Drain Cleaners

Last resort for many homeowners.

Available in hardware stores. Most contain sodium hydroxide or similar chemicals that burn through organic waste.

Read the label carefully. Wear gloves. Don’t mix with other products.

Avoid if the blockage is complete, or if water is sitting in the sink or tub. The chemicals can pool and damage surfaces.

Use sparingly. Too much damages your pipes and creates fumes.

Some homeowners actively warn against using these. One forum member puts it plainly: “I am wary of ALL magic liquid/gels that are for sale, I just know that Drano is a no‑no.”

If the issue returns within days, the blockage is deeper than chemical reach.

When DIY Fails — Time to Call a Plumber

If home remedies haven’t worked, it’s time to stop.

There’s a limit to what boiling water and plungers can handle. When the same drain keeps clogging again and again, there’s usually a deeper issue. Pipes may be damaged, blocked further down, or completely obstructed by tree roots.

Here are clear signs you need help:

• Water rising in other fixtures: Flush the toilet and water bubbles in the shower. That points to a sewer problem.
• Multiple drains slow or backing up: Indicates a mainline issue.
• Foul odours persist: You’ve flushed and cleaned, but the smell won’t go. Could mean a larger blockage, venting issue, or even a break in the pipe.
• Outdoor grates overflowing during rain: Suggests blocked stormwater drains or pipes full of debris or roots.
• Standing water that won’t budge: If a plunger and hot water won’t shift it, the blockage is likely beyond reach.

Trying to force it at this stage can make things worse. Pipes can crack. Sewage can back up. Flooring and walls can suffer permanent damage.

According to QBE insurance data, clogged drains account for 13.4% of all water damage claims in Australian homes. When combined with burst or blocked pipes, they’re responsible for nearly 46% of water damage cases.

For persistent or complex blockages, contact a drain expert in Sydney to inspect the problem properly.

If you’re based in Sydney and need fast help, Graham & Sons Plumbing offers professional blocked drain clearing with same-day service across all suburbs. It’s often quicker and more cost-effective than letting a minor problem turn into a major one.

Keeping Drains Clear Year-Round

Fixing blockages is one thing. Stopping them before they start saves time and money. Maintenance doesn’t need to be intensive or technical. Small habits go a long way.

In the Kitchen

• Pour cooled oil or grease into a sealed container and bin it.
• Use a sink strainer to catch food scraps.
• Avoid rinsing coffee grounds or rice down the drain.
• Flush the sink weekly with boiling water and detergent.

In the Bathroom

• Install mesh drain covers in showers and bathtubs.
• Brush hair before showering to reduce shedding into the drain.
• Pour boiling water down the sink fortnightly to break down soap residue.
• Avoid dumping face wipes or cotton buds down the toilet.

For Toilets

Only human waste and toilet paper should go down.

Anything else—tissues, sanitary items, floss—can block the trap or the line. Even “flushable” wipes don’t break down fast enough and often catch on rough pipe walls.

Outdoor Drains

Leaves and roots are two of the worst offenders. To keep things clear:

• Sweep leaves off outdoor grates regularly, especially after storms.
• Trim back trees with invasive roots near drains.
• Use mesh or covers over drain openings where possible.
• After heavy rain, check for pooling water or overflowing grates.

General Maintenance Tips

Basic upkeep every month or two prevents many common issues.

If a plumber visits for another job, ask them to check your drains as well. It’s quick, and they may spot early signs of an issue.

Quick-Access Troubleshooting Table

Use the table below to narrow down your issue and pick the right fix.

Are You Ready to Prevent the Next Blocked Drain?

Drain problems often start small. React early and you’ll avoid bigger issues.

Some methods are worth trying yourself. But don’t force a fix if the problem keeps returning. It costs more in the long run.

Basic habits in the kitchen, bathroom, and outdoors can reduce blockages significantly. It’s cheaper to prevent than repair. Professional plumbers exist for a reason—use them when needed.