
Standing ankle-deep in soapy water is one of those classic Sydney problems - particularly in older Eastern Suburbs apartments and terrace houses where the drainage hasn't had a serious look in decades. This guide walks you through what's actually blocking your drain, the five DIY methods that work (in the right order), the three things you should NEVER do to a Sydney drain, and how to tell when it's not the shower at all - it's your sewer.
Before you reach for the bottle of caustic drain cleaner under the sink - stop. There's a very good chance that what you're about to do will damage your pipes, scratch your enamel, and not actually clear the blockage. Especially if you live in a heritage Paddington terrace, a 1960s Maroubra brick home, or a Bondi apartment building with cast iron stacks.
Here's how to do this properly.
Before you do anything, run two quick checks. They'll tell you whether you're dealing with a 5-minute fix or a "call the plumber tonight" emergency.
Try the basin in the same bathroom, then flush the toilet. If only the shower is slow, you're almost certainly looking at a localised blockage in the shower waste - hair, soap and skin cells clogging the P-trap or the short section of pipe just below it. Good news: this is the easy version.
If the basin is also slow, or the toilet bubbles when the shower drains, stop everything. This is not a shower-drain problem - it's a sewer line problem. The blockage is downstream of all your fixtures and you've got tree roots, a collapsed section, or a fat/grease build-up in your main drain. Continuing to use water in this state can cause a sewage backflow into the lowest fixture in your home (usually the shower itself). Call a plumber.
In Sydney homes, three culprits cause around 95% of shower blockages:
Less common, but worth knowing: small toys, jewellery, bottle caps, and (in heritage homes) bits of corroded pipe scale that have flaked off the inside of cast iron drains.
A kettle of just-boiled water poured slowly down the drain can dissolve soap scum and shift light blockages. WARNING: Don't do this if you have a porcelain or enamel shower tray - the thermal shock can crack it. Don't do this on PVC drains if you've just had your hot water on either, as combined heat can soften older pipe joints.
It's gross. It's also the single most effective DIY method for a typical shower blockage. Remove the drain cover (usually two screws or a lift-off grate), then use a bent wire coat hanger, a plumbing zip-tool (cheap at any hardware store), or even your gloved fingers to fish out the hair clump. You'll be amazed - and a little horrified - by what comes up.
Fill the shower with 5-10cm of water so the plunger forms a seal. If your shower has an overflow, block it with a damp cloth. Plunge vigorously for 30-60 seconds. The combination of pressure and suction can break up softer blockages that hair removal didn't catch.
A classic for a reason. Pour half a cup of bicarb soda down the drain, follow with a cup of white vinegar, and cover the drain (a wet cloth works) to force the foaming reaction down rather than up. Leave for 15-30 minutes, then flush with hot (not boiling) water. This works on soap scum and mild build-up. It's also pH-neutral by the end, so it won't damage any pipe material in Sydney homes.
If you have access to a shop vac, set it to "wet", seal the hose around the drain, and switch on. The suction is significantly stronger than a plunger and can often pull blockages back up the way they came rather than pushing them deeper.
This is the big one. Caustic drain cleaners - the ones with sodium hydroxide or sulphuric acid - are murder on older pipework. In Eastern Suburbs heritage homes (think Paddington, Surry Hills, parts of Bondi Junction and Darlinghurst), drain stacks are often original cast iron from the 1900s-1940s. These chemicals strip the protective lining and accelerate corrosion massively. Even in modern PVC, repeated use weakens joints. And if the chemicals don't clear the blockage, the next plumber to work on your drain is now exposed to caustic water that splashes back when they snake the line.
It'll scratch the enamel on your shower tray on the way in. It'll punch through the inside of older galvanised drains. And it's rarely long enough to reach the actual blockage, which is usually 30-60cm down the pipe at the first bend.
A partial blockage becomes a full blockage. Standing water sits against pipe walls, accelerating corrosion. Soap scum builds on top of soap scum. And in shared apartment plumbing, your slow drain can become someone else's overflowing one.
If you've tried the methods above and the drain is still slow, it's time to call us. Here's what we actually use - none of which you can DIY:
Usually one of three reasons: long hair in the household, hard water in your area, or a pre-existing pipe issue (slight pipe collapse, scale build-up, or a poorly designed drain run with too many bends). If you're unblocking it more than twice a year, the underlying drain probably needs a professional clean.
No - and no oils, no fats, no grease anywhere in the bathroom drainage. They cool, solidify, and become the glue that holds hair clumps together.
Yes. Enzyme-based and bacterial drain treatments are slow but pipe-safe. They're a good monthly maintenance option, particularly for older homes where caustic chemicals are a no-go.
A smelly drain is often a different problem: a dry P-trap (letting sewer gas back up), biofilm on the pipe walls, or a venting issue. If the drain isn't slow but smells bad, it's worth a plumber visit before it becomes worse.
Tried everything and the drain is still blocked? Call Plumberoo on (02) 9191 8787 - blocked drain service starts from $99+GST, with same-day appointments across the Eastern Suburbs and a fixed quote before any work begins.