Bathroom · DIY guide
How to unblock a shower drain
Nine out of ten slow shower drains are hair and soap in the top 200mm of the waste. Using a plunger and clearing the grate is explicitly permitted DIY in Victoria. Pouring caustic drain cleaner down it is where people turn a small problem into an expensive one.
Legal in Victoria — plunging and clearing traps is permitted maintenance
What you need
- Rubber plunger
- Drain snake or a bent wire hook
- Screwdriver to lift the grate
- Gloves
- 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. Boiling water can soften PVC joints and crack ceramic.
Keep it clear
A $5 hair catcher over the waste prevents almost every recurrence. Cheapest plumbing insurance in the house.
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
When to stop and call someone
If more than one fixture is slow, if water backs up into the shower when the toilet flushes, or if there is a smell outside near the gully, the blockage is in the main drain, not the bathroom. That is licensed drainage work — and tree roots in old Melbourne clay pipes are a very common cause.