How to tell what type of blockage you have
Start by watching the water, because the speed tells you a lot. If it drains slowly but steadily, hair and soap are likely. If it will not drain at all, the blockage may be deeper.
Check other fittings too. If the basin or bath is slow as well, the problem is probably in a shared pipe. This helps you pick the right fix.
Cause 1: Hair and soap in the trap (most common)
Hair and soap collect in the shower trap or just below the grate, because they cling together. Remove the grate and clear what you can see. A plastic hair tool pulls out the rest.
Run hot water afterwards and check the flow. Fit a hair catcher, because it stops most future blockages.
Cause 2: Blocked waste trap under the shower tray
If the grate is clear, the trap under the tray may be blocked, since sludge builds below. You may need to reach it through an access panel. Place a bucket under the trap before you open it.
Clean out the sludge and refit the trap with care. Check for leaks when you run the water. If you cannot reach the trap, ask a plumber.
Cause 3: Blockage in the waste pipe run
A blockage may sit further along the waste pipe, so a plunger may not reach it. A plunger may help, but a long flexible tool reaches further. Take care not to force it.
If the blockage stays, a drainage engineer can clear it. They have rods and jets for the job. See our guide to a blocked outside drain if water also backs up outside.
Cause 4: Shower tray seal and installation issues
A poorly fitted tray may not slope towards the waste. Water then pools. Cracked seals can leak into the floor below.
If you see pooling after you clear the trap, check the slope. A fitter can correct it. Do not ignore leaks, because water can damage the ceiling.
Cause 5: Shared drain fault (multiple fixtures affected)
If several fittings are slow, the fault may lie in a shared pipe or the main drain, since all share it. You may smell sewage or hear gurgling. This needs a professional.
Read our guide to sewer smell for related signs. A camera survey can show the cause.
Preventing shower drain blockages
Fit a hair catcher and empty it after each shower, since hair is the main culprit. Clear the grate once a month. Avoid pouring thick products down the drain.
Flush the pipe with hot water now and then, because it moves soap along. Little and often keeps the drain clear.
Related guides and local help
If you want to know more, read 10 Signs Your Drain Needs a Professional, Not Just a Plunger. You can also read Sewer Smell in the House: Causes and How to Fix Each One and 7 Things You Should Never Flush Down a Toilet in the UK, because they cover closely related problems.
These guides help too: 10 Plumbing Myths That Cost UK Homeowners Serious Money, Tree Roots in Drains: How They Get There and What to Do, Outside Drain Blocked: What to Do and Who Is Responsible, Blocked Drain Clearance Cost Guide: What Affects the Price and Kitchen Drain Problems: Causes, Fixes and Easy Prevention. Each one explains a related topic in plain English.
Need help near you? Read our blocked drain guide first, or see Blocked Drains in Aberdeen and Blocked Drains in Bournemouth. You can also see Blocked Toilets in Bolton, since every service page has a free quote form. We pass each request to a local drainage engineer.
