Complete Guide to Blocked Drains in the UK (2026)

What Causes Blocked Drains?

Kitchen Drain Blockages

Kitchen drains account for 45% of all blockages in UK homes. The primary culprits are fat, oil, and grease (FOG) which solidify in pipes when they cool. Even small amounts accumulate over time, coating pipe walls and trapping food particles.

Prevention tip: Pour cooking oil into a container, let it solidify, and dispose of it in general waste—never down the drain.

Bathroom Drain Blockages

Bathroom drains typically block due to hair combined with soap scum, forming a sticky mass. Shower drains are particularly vulnerable, with hair from just one family member capable of causing a blockage within 3-6 months without preventive measures.

External Drain Blockages

External drains face different challenges. Tree roots are the leading cause, seeking moisture and nutrients from wastewater pipes. Victorian and Edwardian properties with clay pipes are especially vulnerable as roots can penetrate pipe joints.

Main Drain Blockages

When multiple fixtures are affected simultaneously, the blockage is likely in your main drain. Common causes include:

• Accumulated buildup from years of minor deposits
• Root ingress from garden trees and shrubs
• Collapsed or displaced pipe sections
• Foreign objects that have passed through internal drains

Blocked Drain Costs in the UK (2026)

Note: Emergency callouts (evenings, weekends, bank holidays) typically add £50-£100 to base costs.

How to Clear a Blocked Drain Yourself

For minor blockages, these DIY methods work for approximately 60% of simple household blockages:

Step 1: Remove Visible Debris

Put on rubber gloves and remove any visible hair, soap scum, or debris from the drain opening. Use a bucket to catch any water.

Step 2: Try Plunging

Fill the sink or bath with enough water to cover the plunger cup. Place the plunger over the drain and plunge vigorously 15-20 times. The suction should dislodge minor blockages.

Step 3: Use a Drain Snake

If plunging doesn't work, insert a drain snake into the drain. Twist and push gently until you feel resistance, then rotate to break up the blockage. Pull out slowly to remove debris.

Step 4: Flush with Hot Water

Once cleared, pour a kettle of hot (not boiling) water down the drain to flush away remaining debris. For prevention, follow with a baking soda and vinegar mixture monthly.

When to Call a Professional

Stop DIY attempts and call a professional drainage engineer if:

• Water or sewage backs up into your home
• Multiple drains are blocked simultaneously
• Sewage is surfacing in your garden or driveway
• Persistent foul smell that won't clear after cleaning
• DIY attempts have failed after 30 minutes
• Recurring blockages in the same location
• You suspect root damage or collapsed pipes

Preventing Blocked Drains

Prevention is far cheaper than cure. Follow these guidelines to minimize blockage risk:

In the Kitchen

• Never pour cooking oil, fat, or grease down the drain
• Scrape plates into the bin before washing
• Use a sink strainer to catch food particles
• Run hot water after using the sink

In the Bathroom

• Use a drain cover to catch hair
• Clean drain covers weekly
• Only flush the "3 Ps": pee, poo, and (toilet) paper
• Never flush wet wipes (even "flushable" ones)

Outside

• Clear leaves from gully grates regularly
• Check inspection chambers periodically
• Consider root barriers if you have trees near drains
• Have a CCTV survey if buying an older property