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.

Professional tradesperson completing quality work

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.