A slow shower drain usually announces itself gradually. Water pools around your feet a little longer each week, then one morning the shower floor turns into a shallow bath. The good news is that most blockages sit within a hand's reach of the grate and are made of the same things: hair, soap scum, conditioner and skin oils, bound together into a sticky plug.
This guide covers how to clear a blocked shower drain safely, how to clean it so it stays clear, and when the problem is beyond a DIY fix.
What you will need
- Rubber gloves
- A screwdriver, if the grate is screwed down
- A plastic drain-cleaning strip (the barbed kind) or a bent coat hanger with the end blunted
- A torch
- A cup plunger
- A short hand-held drain snake (also called a drain auger)
- Bicarbonate of soda and white vinegar
- An old toothbrush and a bucket
Step 1: Remove the grate and the hair
Put on gloves and lift or unscrew the grate. Many shower wastes have a removable hair catcher or a shallow cup directly under the grate; lift that out and empty it into the bin, not down the toilet.
Shine a torch into the opening. If you can see hair, feed a plastic drain strip down, twist it and pull it back out slowly. Repeat until it comes out clean. This one step clears the majority of slow shower drains.
Scrub the grate and hair catcher with an old toothbrush and warm soapy water before refitting them. Soap scum left on the grate catches the next lot of hair.
Step 2: Flush with hot water
Run the hottest water from your tap into the drain for a minute or two to wash loosened soap scum through.
Be cautious with boiling water. Most modern shower wastes and drainage pipes are PVC, and pouring a full kettle of boiling water straight into them, especially again and again, can soften joints and seals. Hot tap water, or water that has been left to cool for a few minutes after boiling, is the safer option.
Step 3: Bicarb soda and vinegar
For a light build-up of soap scum, or to freshen a drain after removing hair:
- Pour about half a cup of bicarbonate of soda into the drain.
- Follow with about a cup of white vinegar. It will fizz.
- Cover the drain with a plug or a wet cloth and leave it for 15 to 30 minutes.
- Flush with hot tap water.
This is a cleaning method, not a heavy-duty unblocker. It will not dissolve a solid clump of hair, which is why the hair should come out first.
Step 4: Use a plunger
If water still drains slowly, try a cup plunger. Remove the grate, run enough water to cover the rubber cup, then seal the cup over the opening and pump firmly up and down ten to fifteen times before lifting it off. Blocking any overflow or nearby openings on the same waste helps build pressure. Repeat a few times if the water starts to move.
Step 5: Try a hand-held drain snake
A short drain snake reaches past the trap to blockages the strip cannot get to. Feed the cable gently into the drain, turning the handle as you go. When you feel resistance, keep turning to hook or break up the clog, then pull the cable back out slowly and clean it off. Do not force the cable; if it will not pass a bend, stop. Flush with hot tap water when you are done.
What not to do
- Do not mix chemical drain cleaners. Combining different products, or using bleach with an acid-based cleaner, can release harmful gases. Never follow a chemical cleaner with a plunger, as it can splash back onto your skin or into your eyes.
- Do not rely on caustic cleaners as a routine fix. They can damage some fittings and sealants, and if they do not clear the blockage you are left with a basin of chemical-laden water.
- Do not force metal tools into the waste. Hard tools can scratch the waste, puncture the membrane seal around it or dislodge fittings.
- Do not pour cooking fats, grout residue or plaster down the drain. They set in the pipe.
Why a shower drain smells
A drain smell usually comes from one of two things.
Build-up in the grate and trap. Hair and soap scum decompose and give off a musty smell. Cleaning the grate, catcher and trap, then flushing with bicarb and vinegar, usually solves it.
A dried-out trap. Every shower waste has a trap that holds a small amount of water to block sewer gases. In a shower that is not used for a few weeks, such as a guest ensuite, that water can evaporate. Run the shower for a minute every week or two to refill the seal.
If a sewer smell persists after cleaning, or appears in several rooms, it may be a vent, trap or pipe problem, and that needs a licensed plumber.
Keeping the drain clear
- Fit a fine hair catcher under or over the grate and empty it weekly.
- Brush long hair before showering, so less of it goes down the drain.
- Flush the drain with hot tap water once a week.
- Use bicarb and vinegar once a month as routine cleaning.
- Scrub the grate when you clean the shower screen and tiles.
When to call a licensed plumber
Clearing a grate, emptying a hair trap and using a plunger or short snake are simple household maintenance. In NSW, most plumbing and drainage work beyond that — such as dismantling pipework, replacing the waste or clearing the drain line past the trap with machinery — is generally regulated work that must be done by a licensed plumber. If you are unsure, check with NSW Fair Trading or ask a licensed plumber before you start.
Call a licensed plumber when:
- the drain is still blocked after cleaning, plunging and snaking
- more than one fixture drains slowly or gurgles at the same time
- water backs up into the shower when you use another fixture
- there is a lingering sewer smell
- you notice water damage, swelling skirting boards or damp walls near the shower
The last one matters. Water appearing outside the shower is often a sign that the waterproofing around the waste has failed, and clearing the drain will not fix that.
If the shower keeps giving trouble
Drains that block constantly, pond in corners or leak around the waste can point to poor falls or a failed membrane rather than simple hair build-up. Our waterproofing and bathroom tiling pages explain how falls, wastes and membranes are built to last. Costs depend on size, layout and finishes — see our cost guide or book a quote for a price on your job. If you are in the Penrith area, we can take a look and tell you what the shower needs.
Questions people ask before they commit
What is the fastest way to unclog a shower drain?
Lift the grate and pull out the hair by hand or with a plastic drain-cleaning strip. That alone fixes most slow drains. If water still drains slowly, use a plunger or a short hand-held drain snake.
Can I pour boiling water down a shower drain?
Be careful. Most modern shower wastes and pipes are PVC, and repeatedly pouring boiling water into them can soften joints and seals. Hot tap water or water that has cooled for a few minutes after boiling is the safer choice.
Does bicarb soda and vinegar unclog a drain?
It helps loosen light soap scum and freshen a drain, but it will not dissolve a matted clump of hair. Remove the hair first, then use bicarb and vinegar as part of regular cleaning.
Why does my shower drain smell?
Usually because of trapped hair and soap scum, or because the water seal in the trap has dried out in a shower that is rarely used. Clean the grate and trap, then run the shower for a minute to refill the seal. A persistent sewer smell needs a licensed plumber.
When should I call a plumber for a blocked shower?
Call a licensed plumber if the blockage is beyond the trap, if several fixtures drain slowly at once, if water backs up into another fixture, or if there is a sewer smell or water leaking outside the shower.