A shower draining slowly is usually hair and soap caught in the first 200mm of pipe. That much you can clear yourself in twenty minutes. Occasionally it is the sewer line further down, which you cannot, and the two look identical from where you are standing.
One test separates them, and it takes about a minute.
The short version
- One fixture slow, nothing else affected: hair. Yours to fix.
- Two or more fixtures slow: the line they share. Not hair.
- Slow plus gurgling, or slow plus a smell: further down than you can reach.
- Worse after heavy rain: a structural fault in the line, not a blockage at all.
The One-Minute Test: Is Anything Else Slow?
Fill the basin in the same bathroom, then pull the plug and watch it. Do the same with the bath if you have one. Flush the toilet.
If the shower is the only thing struggling, the problem is in the shower’s own short branch of pipe, and that is where hair collects. If the basin is sluggish too, or the toilet is lazy, then the fault is in the line they share, and nothing you do at the shower grate will change it.
That single distinction decides whether this is a Saturday morning job or a phone call, and almost every article on this subject skips it.
When It Is Hair (and How to Actually Get It Out)
Hair blockages are not distributed along the pipe. They form in a very specific place: at the grate, in the trap, and in the first 100mm to 200mm past it. Hair catches on the grate underside and on any rough edge in the trap; soap scum and conditioner bind it together, and it becomes a mat that water has to filter through.
The useful consequence of that: if you cannot reach the blockage within the first half metre of pipe, it is not hair. Hair does not travel. That one fact rules out most of what people waste money on.
To clear it properly:
- Lift the grate. Most unscrew or lever up. Take the screws out rather than working around them.
- Get the mat out physically. A plastic drain zip tool costs a few dollars and works better than anything you can pour in. Gloves.
- Clear the trap below it. This is the part people skip, and it is where most of the mass usually is.
- Flush it through with a full bucket, not a running tap. Volume moves what is left. A trickle does not.
Baths are harder than showers for one structural reason: a bath waste usually runs to a trap you cannot see or reach without access from below or behind. If a bath is slow and the grate is clean, that is a plumber’s job earlier than the equivalent shower would be.
If flow comes back and stays back, you are finished. If it comes back for a fortnight and then goes again, you did not have a hair problem. You had a hair symptom.
When It Is Not Hair: Four Signs It Is Further Down
More than one fixture is affected. The single clearest sign. Fixtures only share behaviour because they share a pipe.
It gurgles. Noise means air is being forced back through a trap because it cannot get past a restriction or up the vent. Worth understanding properly, because a shower that gurgles but drains fine is a different fault again, and what the gurgling actually means depends on when you hear it.
There is a smell. Hair and soap smell stale. A sewer smell means the trap seal is being pulled down or the problem is past the trap entirely.
It is worse during or after heavy rain. This one is conclusive, and it has nothing to do with hair. Rain affecting your drains means stormwater is entering the wastewater line through a crack or a low gully. That is a structural fault, so clearing the line will not stop it from recurring.
Why “Slow” Is the Stage Before “Blocked”
A slow drain is not a mild version of a blocked drain. It is an earlier one.
Whatever is narrowing the pipe is also catching things, so the narrowing accelerates. The bore goes from restricted to nearly closed over weeks or months, and the interval between problems shortens each time. People rarely notice because the change is gradual enough to adapt to. You start running the shower a little less hard. You stop noticing the water around your feet.
Then one evening the line does not cope, and if the fault was in the main rather than the branch, what you get is waste backing up into the shower, which is a different order of problem and a different order of cost.
The honest summary: hair in a shower branch will never do that. A slow main line eventually will. Which is exactly why the test at the top of this page is worth the minute it takes.
Cleared the grate and it is still slow?
Call R&G on 0420 146 747 and tell us what else in the bathroom is affected. Licensed Sydney plumbers, $0 call-out fee, and if it sounds like something you can still sort out yourself, we will say so on the phone.
What Not to Pour Down It
Caustic drain cleaner. On a hair mat, it dissolves the surface and leaves the bulk, so you get a few days of flow, and the mat re-forms. On a main line fault, it never reaches the problem at all. Either way, you are left with a pipe full of caustic liquid, which is a real hazard for whoever opens the trap next. That is often you, twenty minutes later.
Boiling water into a slow shower. It loses its heat within the first metre, and most modern waste pipes are PVC, which does not appreciate it. It will soften soap scum at the grate and do nothing beyond that.
Bicarb and vinegar. The fizzing is a neutralisation reaction that produces gas and warm water. It is mildly useful on odour and effectively useless on a hair mat you could have pulled out with a two-dollar tool.
None of these is dangerous in the sense of ruining your plumbing. They are just the reason people spend six weeks not fixing a twenty-minute problem.
What a Plumber Does When It Is Not Hair
Confirms the scope first. Which fixtures, how long, whether it has happened before. A drain that has been cleared before and comes back is a different conversation from a first occurrence, and the second one should involve a camera.
Clears the line. An electric eel for solid obstructions and roots; high-pressure jetting where the problem is fat or accumulated debris. On a bathroom branch, this is usually quick.
Puts a camera down it if it is recurring. This is where the money either gets spent well or wasted. A camera run shows whether the pipe is sound and simply needed clearing, or whether there is a cracked joint, a root entry or a sagging section holding water, and it marks the depth and distance. Without that, a recurring slow drain just gets cleared again on a cycle, and the honest name for that is a subscription. What it shows determines whether you need a drain repair or nothing at all.
On cost, a straightforward bathroom branch clear sits at the lower end of drain pricing. Our guide to blocked drain costs in Sydney has the ranges by job type.
Frequently Asked Questions
How slow is too slow?
A healthy shower should keep up with the water you are putting into it, with no pooling around your feet. Standing water while the shower is running means the drain is already passing less than the tap delivers, which is well past the point worth acting on.
Is a hair catcher worth using?
Yes, and it is the only prevention on this page that reliably works. A grate-top catcher emptied regularly stops the mat forming in the first place. It will not help with anything further down the line, but it removes the most common cause entirely.
My shower is slow, but the water eventually goes. Can I leave it?
If it is hair and only that shower, leaving it means it gets slower, and the eventual clean-out is messier. If other fixtures are involved, leaving it means the restriction keeps narrowing until the line stops coping. Neither is urgent this week. Both get worse rather than better.
Why is my bath slower than my shower?
Usually because a bath holds and releases a large volume at once, which exposes a narrowed line that copes fine with a shower’s slower flow. It is the same reason a washing machine or dishwasher often reveals a problem before any other fixture does.
Sort it while it is still slow
A slow drain is the cheapest stage to deal with, and if it turns out to be hair at the grate we will tell you that rather than sell you a drain clear. $0 call-out fee, fixed price before any work starts, covering the North Shore, the Hills and Western Sydney. See how we handle blocked drains across Sydney.
