How often should you clear slow drains?

Slow drains become full blockages and backups if ignored.

A fully blocked drain backs up into the fixture and, in a shared stack, potentially into a lower one. Grease that has cooled and set in a horizontal run is genuinely difficult to remove, and repeated chemical attempts damage older pipework and traps.

1. Clear the visible debris first. Lift out the stopper or strainer and remove the hair and soap film that has collected on it. This alone fixes many slow drains.
2. Try a drain snake or hair removal tool. A cheap plastic barbed strip pulls out the hair mat sitting just below the plughole, which is where most bathroom blockages live.
3. Flush with very hot water. Not boiling on plastic waste pipes or on porcelain, which can crack. Hot tap water for several minutes.
4. Use bicarbonate and vinegar for maintenance. Half a cup of bicarbonate followed by a cup of vinegar, left for thirty minutes and flushed. This is a maintenance measure rather than a cure for a real blockage.
5. Plunge properly if it is slow. Block the overflow with a wet cloth first, or the plunger just pushes air around. Use a cup plunger on sinks.
6. Clean the trap if that fails. Bucket underneath, unscrew the two collars on the U-bend, clear it, and refit. This is the single most effective sink fix and needs no tools on most plastic traps.

• Water pooling around your feet in the shower
• A sink taking noticeably longer to empty than it used to
• Gurgling from another fixture when one drains, which indicates a venting problem or a partial blockage further along
• A persistent smell from the drain
• Repeated blockages in the same fixture, which suggests a problem in the pipework rather than at the plughole

• Reaching for caustic drain cleaner first: it damages older pipes, is dangerous if it does not clear the blockage and sits in standing water, and rarely fixes a hair mat
• Pouring fat and cooking oil down the sink, which is the origin of most kitchen blockages and of sewer fatbergs
• Plunging without blocking the overflow, so the pressure escapes
• Using a plunger after adding chemical cleaner, which can splash caustic liquid

• Long-haired households need bathroom drains cleared far more often
• Kitchen sinks in households that cook with a lot of fat need more attention
• Older cast iron or clay drainage has a rougher internal surface and catches debris more readily
• Tree roots in external drains cause recurring blockages that no amount of plunging fixes

Recurring blockages in the same place, multiple fixtures backing up at once, or any sewage smell or backup outside all indicate a problem in the main drain rather than the fixture. That needs a drainage specialist, often with a camera survey.