Bathroom · DIY guide
How to unblock a shower drain
Nearly every slow shower drain in Melbourne is hair and soap scum bound together in the first few hundred millimetres below the waste. That part you can deal with yourself. The part worth knowing before you start is where the line sits in Victoria between clearing a blockage and doing plumbing work, because it is further back than most online guides suggest.
Legal in Victoria — plunging and clearing traps is permitted maintenance
Checked as at September 2026. Rules and prices change — confirm anything you are about to act on.
What you need
- Rubber plunger
- Drain snake or a bent wire hook
- Screwdriver to lift the grate
- Gloves and eye protection
- Bucket and old towels
- Bicarb soda and white vinegar for the finish
Step by step
Lift the grate and clear what you can reach
Most grates lift out or unscrew. The blockage is usually visible and within arm's reach. Hook it out with a bent wire or a drain snake — this alone fixes most slow showers.
Plunge properly
Run enough water to cover the plunger cup, block any overflow, and plunge with short sharp strokes keeping the seal. Twenty firm strokes beats two minutes of gentle ones.
Snake the trap if it is still slow
Feed the drain snake in slowly, turning as you go. When you meet resistance, keep turning rather than pushing hard — you want to break the blockage up, not compact it further down the line.
Flush with hot water and bicarb
Half a cup of bicarb, a cup of white vinegar, leave ten minutes, then a kettle of hot — not boiling — water. Skip all of this if chemical drain cleaner has already gone down the drain: do not plunge it, do not add vinegar or anything else to it, flush with cold water and call a plumber. Boiling water can soften PVC waste joints, which is what most modern drains are made of.
Keep it clear
A $5 hair catcher over the waste prevents almost every recurrence. Cheapest plumbing insurance in the house.
What is actually down there
Not a mystery: hair, bound together with the fatty residue from soap and conditioner into a grey mass that sits just under the waste grate or in the bend below it. It builds slowly, which is why the shower gets gradually slower over months rather than blocking overnight.
The useful diagnostic is where else the water is slow. If it is only the shower, the blockage is local and yours to deal with. If the shower, the basin and the toilet are all slow, or water rises in one fixture when you use another, that is a problem further down the drain line — often tree roots in an older Melbourne property — and it is a licensed plumber's job with a camera, not a coat hanger.
Start with the least destructive thing that works
Lift the grate. On most shower wastes it either unscrews or lifts straight out. A surprising share of blockages are visible from here and can be hooked out with gloved fingers or a pair of long-nose pliers in about ninety seconds.
If nothing is visible, a plastic barbed drain tool — the flexible strip with backward-facing teeth, a few dollars from any hardware store — goes down two hundred millimetres and drags the mass back up. It is unpleasant and it is extremely effective. This tool solves the majority of slow shower drains and it should be the first thing you buy, not the last.
Boiling water, and when not to use it
Very hot water softens the soap binding the hair together and can shift a partial blockage on its own, especially after you have removed what you can reach.
Do not pour boiling water into an acrylic shower base, and be careful with PVC waste pipes — sustained boiling water can soften and distort both. Hot from the tap is safe everywhere; kettle-boiling is for ceramic and stainless only, and even then in stages rather than all at once.
The plunger, and why it often does nothing in a shower
A plunger works by hydraulic pressure, which requires a seal. In a shower that means covering the waste completely and having enough water in the base to cover the plunger cup. It also means blocking the overflow if there is one.
Most people plunge a shower with a dry base and a cup that does not seal on a large flat floor, achieve nothing, and conclude the blockage is serious. Add water first.
Where the line is in Victoria
Clearing a blockage with a plunger is the one action consistently described as homeowner territory. Removing the grate and pulling hair out with a hand tool is maintenance by any reasonable reading.
Beyond that it gets grey quickly, and it is worth being straight about it: Victoria publishes no homeowner DIY-plumbing exemption list at all. The tidy list you will find on a dozen websites — washers, showerheads, cistern valves, clearing traps — is Western Australia's, published as a deliberate reform in 2024. It has no application here. The Victorian regulator's position is simply that plumbing work requires a licensed practitioner, with minor like-for-like maintenance accepted in practice rather than by written exemption.
Practical consequence: pulling hair out of a waste is fine. Dismantling a trap, cutting into a waste pipe, or running a powered drain machine into the line is not a job to improvise, and if the work would have needed a compliance certificate had a plumber done it — anything over $750 — it was never yours to do. Read the Victorian rules in full.
Chemical drain cleaners: read this before you buy one
They are caustic, they are only sometimes effective on a hair-and-soap blockage, and they create a genuine hazard for whoever opens that drain next — which may be you in an hour, or a plumber tomorrow with no idea there is a litre of caustic solution sitting in the trap.
If you have already used one and it has not worked, say so when you call a plumber. It changes how they approach the job and it is a safety issue, not an embarrassment. Never use one after a drain machine has been run, and never mix two different products in the hope that one of them works.
Stopping it happening again
A hair catcher over the waste costs a few dollars and eliminates the problem almost entirely. Empty it weekly and you will not read this guide again.
Once a month, run the hot tap into the shower for a minute or two. It keeps the soap residue moving rather than letting it set into the film that catches everything else.
Common mistakes
- Caustic drain cleaner — it damages seals and PVC, and makes the plumber's job hazardous later
- Boiling water down PVC waste lines
- Pushing the blockage further down instead of breaking it up
- Ignoring a slow drain until it backs up completely
Questions people ask
Every drain in the house is slow, not just the shower.
That is not a fixture blockage, it is the drain line. In older Melbourne properties tree roots in earthenware pipes are a common cause. It needs a licensed plumber with a camera — a chemical cleaner will do nothing to a root mass.
Is it safe to use a drain snake myself?
A short hand auger used gently is usually fine. A powered drain machine is not a homeowner tool — it can punch through an old pipe, and then a blockage becomes an excavation.
The water smells bad but drains fine.
Usually a dry or damaged trap letting sewer gas back through, common in a shower that has not been used for a while. Run water into it first. If the smell persists with a wet trap, get it looked at.
Can I pour bleach down to kill the smell?
It masks it briefly and does nothing about the cause. If the trap is dry, water fixes it. If it is not, bleach is not the answer.
When to stop and call someone
Multiple fixtures backing up, water rising in one fixture when you use another, or sewage smell with a wet trap — stop. That is a drain-line problem and it needs a licensed plumber with a camera before it becomes a much bigger job.
This guide is general information, not advice for your particular house. Rules change — check the current position with the Building and Plumbing Commission, Energy Safe Victoria and WorkSafe Victoria before you rely on it. Plumbing, gas and electrical work must be done by a licensed practitioner. If your home was built or last renovated before 1990, assume asbestos until it is ruled out — see what a strip-out finds.