How to Unblock a Bath: Clearing Hair and Soap Scum Without Wrecking Your Seals
Water sitting round your ankles for twenty minutes after you’ve pulled the plug isn’t a plumbing mystery. It’s hair. Specifically, it’s hair wound round soap scum into a rope that’s sat at the trap for months, growing a bit fatter every wash. Leave it long enough and that rope turns into a solid plug that no amount of hot water is going to shift.
Most people reach for a bottle of drain gel first. Wrong move, and I’ll explain why in a minute. If you want to know how to unblock a bath properly – without melting your rubber seals or scalding your hands – the method below is the one I’ve used on hundreds of call-outs across the south east. It works in about fifteen minutes and costs less than a fiver in kit.
What You Will Need: How to unblock a bath
You don’t need a plumber’s van full of gear for this. A soap-scum-and-hair blockage sits right at the plughole or just below it in the trap, so the tools are simple.
- Rubber gloves – this job is genuinely unpleasant
- A drain claw or “zip-it” hair tool (under £3 from any hardware shop)
- An old towel or dust sheet for the floor
- A small flathead screwdriver
- A bucket
- Bicarbonate of soda and white vinegar (optional, for the final flush)
- A torch or phone light
Notice what’s missing: caustic soda, bleach, or any bottled “drain unblocker”. Those products heat up as they react, and on an older bath with a rubber or plastic overflow gasket, that heat can soften or perish the seal. WRAS (wras.co.uk) has flagged exactly this failure mode in domestic waste fittings for years – a chemical clear that trades one problem for a slow leak under the bath panel.
Step-by-Step Method to Unblock a Bath Drain
Follow these in order. Don’t skip to the plunger – it’s step four for a reason.
1. Clear standing water first
Bail out most of the water with a cup or small jug into your bucket before you start. You can’t see what you’re doing through six inches of grey water, and you don’t want it going everywhere when you pull the plug on the real problem.
2. Remove the plughole cover or strainer
Most modern baths have a pop-up waste or a strainer held by a single central screw. Undo it with the flathead screwdriver and lift the whole assembly out. This alone solves the blockage on maybe one job in five – the hair mass is sitting right there, wrapped around the strainer itself.
3. Hook the hair with a drain claw
This is the chemical-free method and it’s the one worth remembering. Feed the drain claw down the waste pipe, past the trap bend, twisting gently as you go. When you feel resistance, twist the handle to snag the hair, then pull straight up – slowly, not in one yank, or you’ll strip the hair off the claw halfway out.
I had a job in Woking last spring where the customer had been living with a bath that took forty minutes to drain for the best part of a year. Three pulls with a claw, maybe ninety seconds of actual work, and we lifted out a hair-and-scum plug roughly the size of a golf ball. She’d been about to book a full drain survey. She needed three quid of wire.
4. Run hot water, then try the plunger if needed
Run the hottest tap water you can for two minutes to soften any remaining scum. If the bath is still slow to clear, a sink plunger (not the toilet type – flat cup, not flanged) will shift what’s left. Block the overflow hole with a wet cloth first or you’ll just be pushing air instead of pressure.
5. Flush with bicarbonate of soda and vinegar
Once the water’s running freely, tip half a cup of bicarbonate of soda down the plughole followed by a cup of white vinegar. It’ll fizz for a minute – that’s normal, it’s breaking down the last of the soap film on the pipe walls. Follow with a kettle of hot (not boiling, if you’ve got plastic pipework) water.
6. Test with a full bath’s worth of water
Don’t just run the tap for ten seconds and call it fixed. Fill the bath a few inches, pull the plug, and time how long it takes to clear. Under thirty seconds for a few inches of water is normal. If it’s still sluggish, you’ve likely got a blockage further down the branch pipe rather than at the trap – which is where step-by-step DIY stops and you need a proper look with a camera, as covered in our guide to unblocking a drain more generally.
When to Stop and Call a Pro
Know when you’re out of your depth. If you’ve hooked out visible hair and scum but the bath still drains slowly, or if water is coming back up through the bath when you flush the toilet, that’s not a bath problem any more – that’s a shared branch or stack issue.
CIPHE (ciphe.org.uk), the industry body for plumbing engineers, is clear that persistent slow drainage across multiple fixtures usually points to a blockage beyond what a domestic drain claw can reach – often 3 to 6 metres down the branch line, sometimes at a joint that’s collapsed or root-damaged if the pipe runs near a garden.
A CCTV drain survey at that point isn’t overkill, it’s the only way to actually see what you’re dealing with rather than guessing. Typical cost for a domestic CCTV survey in the UK sits between £120 and £180, and it tells an engineer exactly where the problem is before anyone touches a rod. You can see roughly what that covers on our drain unblocking cost page.
If you’re in London and this has turned into more than a bath job, our drain unblocking and drainage services in London team carries CCTV kit on every van. Same goes if you’re further out – we cover Eastbourne and Hove around the clock too.
If you’ve genuinely had enough of fighting it yourself, click to call our team and we’ll talk you through whether it’s a job for a claw or a camera before anyone books anything.
How to Prevent It Next Time
A bath not draining properly is almost never a one-off. It’s a pattern, and patterns are fixable.
Water UK (water.org.uk) has been running public awareness campaigns for years about what actually causes household blockages, and hair combined with fats, oils and cosmetic products tops the domestic list right alongside kitchen grease. A bath collects less grease than a kitchen sink, but it collects a lot more hair, especially in a house with long-haired kids or someone who showers over the bath daily.
- Fit a mesh strainer over the plughole – the £2 kind from any supermarket catches hair before it reaches the trap. Rinse it weekly.
- Do a monthly bicarb-and-vinegar flush – even with no visible blockage, it stops scum building on the pipe walls in the first place.
- Wipe down the overflow slot – it’s the one part people forget, and soap scum collects there just as fast as at the main plughole.
- Don’t rinse shaving residue straight down the bath waste – it binds with soap scum faster than almost anything else that goes near a bath.
One landlord I did a job for in Lewisham had the same tenant call about a slow bath three times in a year. Fitting a £2 strainer in every bathroom in that property ended the call-outs completely. Cheapest fix I’ve ever recommended, and it worked better than the last two “professional” clears combined – because those clears never touched the actual cause.
If you’re a landlord dealing with repeat call-outs across a few properties, our team also covers Lewisham and Abbey Wood around the clock, which covers most of that recurring-tenant problem in one visit.
FAQ
Why is my bath not draining even though the plughole looks clear?
The visible plughole is rarely where the blockage sits. A blocked bath drain is almost always at the trap, a few inches below where you can see, or further down the branch pipe. Pulling the strainer and looking isn’t enough – you need to get a claw or a plunger actually into the waste.
Can I use a wire coat hanger to unblock bath plughole blockages?
You can, and plenty of people do, but a proper drain claw costs about the same as a coffee and won’t scratch chrome fittings or snap off inside the pipe the way a bent hanger can. Worth the extra minute to buy the right tool.
Is it safe to use chemical drain cleaner on a bath not draining well?
Sparingly, and never on an older bath with worn rubber seals. The exothermic reaction in most bottled cleaners can degrade gaskets and plastic overflow fittings, which is why WRAS flags them as a secondary cause of leaks. A claw and a bicarb flush handle 90% of bath blockages without the risk.
Here’s the real saving: a £3 drain claw and fifteen minutes stops a job that, left three more months, turns into a £150 CCTV survey and a possible trap replacement. Prevention is the cheapest plumbing you’ll ever do.
Still stuck, or the water’s coming back up somewhere it shouldn’t? Click to call and we’ll get an engineer to walk you through it or book you in the same day.
Understanding how to unblock a bath early helps you budget and avoid bigger repair bills later.
