A blocked shower floor drain: what to try before calling a plumber

What usually causes the blockage

A shower floor drain collects hair, soap residue, and skin cells, and unlike a sink these don't get flushed through by a fast stream of water. Hair catches on the grate or just below it, soap forms a waxy coating on the pipe wall, and over weeks the two combine into a soft plug that slows drainage without stopping it completely.

In older Tallinn buildings, where the floor drain and its trap were fitted decades ago, the pipe diameter is often narrower than in a new build, so the same amount of hair blocks it faster. In newer flats with a shower tray rather than an open drain, the same buildup happens in the trap under the tray, which is harder to reach but works the same way.

How to clean the grate yourself

Start by lifting out the drain cover or grate — most simply pull up or unscrew with a flat screwdriver. Underneath you'll usually find a mat of hair and soap scum sitting on or just above the trap. Pull this out by hand or with a bent piece of wire, wearing gloves, and wipe the inside of the visible pipe with an old cloth.

A dedicated drain brush, sold cheaply in any hardware shop, is worth having: its bristles are shaped to hook hair out of a narrow pipe rather than just pushing it further down, which is what happens if you use a straight object. Work it in and rotate rather than jabbing.

Once the visible section is clear, run hot water from a kettle or the shower for a minute and watch how fast it drains. If it's back to normal, you're done. If it still drains slowly, the blockage sits further down than a brush or wire can reach.

The baking soda and vinegar method, if you don't have a drain wire

If you don't have a drain brush or plumber's wire to hand, or the blockage isn't a solid clump of hair you can pull out, a baking soda and vinegar treatment can shift a softer buildup of soap and grease. Pour around 100 grams of baking soda into the drain, followed by 100–150 millilitres of white vinegar.

The mixture fizzes as it reacts, which helps loosen residue clinging to the pipe wall. Leave it for 15–20 minutes, then flush through with a full kettle of hot (not boiling) water. This is a reasonable first attempt on a slow drain, but it won't clear a solid mass of hair — for that, mechanical removal with a brush or wire works better.

Skip shop-bought caustic drain cleaners in a bathroom with plastic pipework or an older enamel-coated cast iron trap — they can damage seals and gaskets over repeated use, and they don't do anything a kettle of hot water and a brush won't.

What a bad smell without a visible blockage usually means

If the drain runs freely but there's a persistent smell of sewage or damp from the shower area, the grate and trap are probably clean and the cause lies elsewhere. The most common reason is a dry trap: if the shower isn't used for a week or two, the water sitting in the U-bend that normally seals off sewer gas evaporates, and smell comes straight up the pipe.

The fix is simply to run water down the drain for thirty seconds every week or two if the shower goes unused — a holiday home or a spare bathroom are typical cases. If the smell persists after refilling the trap, the seal around the drain fitting itself, or a damaged gasket further down, may need attention, which is a plumbing job rather than a cleaning one.

When to call a plumber

If the drain is still slow after clearing the grate and trying the baking soda method, the blockage sits deeper in the pipe than you can reach by hand, and that needs proper rodding equipment or a pipe camera to locate. This is especially likely in older buildings where the horizontal run to the stack can be long and narrow.

It's also worth calling in a plumber if water backs up from the floor drain when you run the washing machine or another fixture on the same line, which points to a blockage or a sagging section of pipe shared between fixtures rather than something local to the shower.

Plumbing work like this starts from 45 € per hour, and if the shower tray or drain fitting itself needs replacing rather than just clearing, that's closer to a toilet repair and fitting job — from 60 € per job — which we quote once we've seen what's underneath.

• Grate cleaned and trap cleared by hand, drain still slow
• Baking soda and vinegar tried, no improvement after flushing with hot water
• Water backs up when another fixture on the same line is used
• Smell persists after refilling a dry trap
• Gurgling or bubbling noises from the drain during use

What not to try yourself

Avoid repeated doses of caustic or acidic drain cleaner if the first application hasn't worked — it won't clear a blockage it couldn't shift the first time, and it risks damaging pipe seals and any chrome or plastic fittings around the drain. Two or three applications a week apart is not a strategy, it's a way of making the eventual repair more expensive.

Don't take the trap apart under the floor drain unless you're confident about reassembling the seal correctly, since a poorly reseated trap leaks into the subfloor rather than the shower, which is a much worse problem in a flat with neighbours below. And don't force a rigid wire or hanger down the pipe with real force — it's more likely to puncture a plastic elbow than clear a blockage.