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Tips & AdviceUpdated May 2026By TradeMatch Editorial Team·9 April 2026·Updated 12 April 2026·6 min read
Drainage Problems UK: Costs, Causes & How to Fix Them
Blocked, collapsed or slow drains affect thousands of UK homes. Here is how to identify drainage problems, what they cost to fix, and when to call a professional.
Drainage Repair Costs
| Problem | Average Cost |
|---|---|
| Drain unblocking (jetting) | £80–£200 |
| CCTV drain survey | £100–£350 |
| Drain relining (per metre) | £60–£100 |
| Drain excavation and repair | £500–£2,000 |
| Collapsed drain replacement | £1,000–£4,000 |
| Soakaway installation | £500–£1,500 |
| Septic tank installation | £3,000–£8,000 |
| Manhole cover replacement | £100–£300 |
Common Drainage Problems
Blocked drains — Usually caused by fat, grease, wet wipes or tree roots. Signs: slow drainage, gurgling sounds, bad smells.
Collapsed drains — Older clay pipes deteriorate over time. Signs: recurring blockages, sinkholes in the garden, sewage smells.
Tree root ingress — Roots seek out moisture and can crack or invade drain joints. Common with older clay or pitch fibre pipes.
Surface water flooding — Inadequate drainage or blocked soakaways. Increasingly common due to climate change and more paved surfaces.
Who is responsible? — You are responsible for drains within your property boundary. Shared drains and public sewers are the responsibility of your water company.
Frequently Asked Questions
Should I get a drain survey before buying a house?
Highly recommended, especially for older properties. A CCTV drain survey costs £100–£350 and can reveal expensive hidden problems. Many conveyancing solicitors now recommend drain surveys as standard.
Can I unblock a drain myself?
Simple blockages (hair, soap) can often be cleared with a plunger, drain rod or enzyme-based cleaner. Do not use caustic chemicals — they can damage pipes. For persistent or deep blockages, professional jetting is more effective and safer.
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