Leak repair is one of those jobs where the cost range is genuinely wide — because the complexity range is genuinely wide. A weeping joint under the sink is a very different job to a leak inside a wall or under a concrete floor.
Here's how costs break down and what affects them.
Typical costs for leak repair
| Type of leak | Typical cost range | |-------------|------------------| | Visible pipe joint leak (accessible) | £80–£150 | | Under-sink pipe repair | £80–£150 | | Radiator valve replacement | £100–£180 | | Leaking tap (washer/cartridge) | £80–£150 | | Concealed pipe leak (inside wall) | £200–£600+ | | Leak under concrete floor | £400–£1,500+ | | Emergency call-out (nights/weekends) | Add £50–£100 |
The wide ranges reflect two things: the time it takes to access and fix the leak, and whether any materials need replacing beyond the repair itself.
What drives the cost up
Access
A leak on a clearly visible pipe joint is quick. A leak inside a wall or under a floor means opening up the structure to get to it — and making good afterwards. That's where costs rise significantly.
How long it's been left
A slow leak that's been dripping for months creates secondary damage — damp, mould, softened plasterboard, timber rot. The leak repair itself might be £150, but the associated work costs considerably more.
Emergency timing
Out-of-hours call-outs — evenings, weekends, bank holidays — attract a premium. If the leak can safely wait until normal working hours, it's worth waiting.
What you can do while waiting for a plumber
If you can't get someone out immediately:
- Turn off the water at the stopcock (usually under the kitchen sink) — this stops the leak immediately
- Turn off the boiler if the leak is near pipework connected to the heating system
- Collect the water to protect floors and ceilings
- Take photos for your insurance claim
Leak detection — when the source isn't obvious
If you have evidence of a leak (damp patch, rising water bill, falling boiler pressure) but can't find where it's coming from, a leak detection survey may be needed. This uses specialist equipment — thermal imaging or acoustic detection — to locate the source without unnecessary opening up of walls or floors.
Leak detection typically costs £150–£300 and is worth it before committing to a large excavation job on a guess.
Insurance
If the damage is significant, check your home insurance before paying for repairs yourself. Many buildings insurance policies cover trace and access — the cost of finding and accessing the leak — even if the leak repair itself isn't covered.
If you've got a leak in Hemel Hempstead, Ealing, or NW London — get in touch. We'll assess it, tell you what's involved, and give you a clear price before we start.