Introduction
Living in London means busy streets, historic properties, and – unfortunately – some very old drainage systems. Combine that with modern city living, and it’s no surprise that blocked drains are one of the most common plumbing problems we deal with at Drain Detectives.
From Camden to Croydon, we’ve seen it all. Here are the top causes of blocked drains in London – and how you can prevent them from happening in your home or business.
1. Grease, Fat & Oil from Cooking
London is full of takeaways, cafés and restaurants – and even at home, frying food is part of everyday cooking. When hot oil and grease are poured down sinks, they cool and harden inside pipes, creating a sticky mess that traps other waste. Over time, this builds up into stubborn blockages and even the infamous London “fatbergs.”
Common culprits in London kitchens:
- Curry sauces, gravies & cooking oils
- Fish & chips residue
- Bacon, sausages & meat fats
- Oil from fried chicken shops and fast-food takeaways
Prevention Tip:
Collect oil and grease in a jar or tin and throw it in the bin, not down the sink. If you run a restaurant or takeaway, you should use proper grease traps (required by law in many London boroughs).
2. Food Waste Build-Up
Many Londoners live in flats with smaller sinks and older plumbing, which can block more easily. Food scraps, rice, pasta, and coffee grounds are particularly bad offenders as they expand or clump together in pipes.
Prevention Tip:
Use a sink strainer to catch food particles. Scrape plates into the bin before washing up.
3. Hair in Bathroom Drains
In shared London flats and busy households, bathroom drains quickly collect hair mixed with soap scum, which forms tough clogs.
Prevention Tip:
- Fit a cheap drain cover or hair catcher over your plughole.
- Use a simple plastic “drain snake” tool to pull hair out before it builds up.
- Flush the plughole occasionally with boiling water to reduce soap scum.
4. Things That Should Never Be Flushed
London’s Victorian sewers are under constant strain. Items that don’t break down cause huge blockages both in your pipes and the wider sewer network.
Things you should never flush:
- Wet wipes (even “flushable” ones)
- Cotton buds
- Dental sticks
- Kitchen roll & paper towels
- Cotton wool pads
- Sanitary products
- Condoms
Prevention Tip:
Remember the golden rule – only flush the 3 P’s: pee, poo & (toilet) paper. Everything else belongs in the bin.
5. Tree Roots in Old Pipes
London is famous for its plane trees, along with willows and poplars in parks and gardens. Their roots naturally seek out moisture, meaning they can grow into small cracks in old clay pipes, causing major blockages and even collapsed drains.
Prevention Tip:
If you live in an area with large trees near your drains, book a CCTV drain survey to spot root intrusion early before it leads to costly repairs.
Conclusion – Professional Drain Unblocking in London
From greasy takeaways in Hackney to tree-rooted drains in leafy Dulwich, blocked drains are a fact of life in London. The good news is, most can be prevented with a little care.
But if you’re already dealing with slow-draining sinks, bad smells, or an overflowing toilet, it’s time to call in the professionals.
At Drain Detectives, we provide:
24/7 emergency drain unblocking across London
CCTV drain surveys to diagnose hidden issues
Professional drain repairs and root removal
Call us today on 020 8168 9981 or email info@draindetectives.co.uk for fast drain unblocking in North, South, East, West and Central London.