How to deal with a leaking pipe joint: stopping the water, identifying compression, push-fit and soldered joints, tightening or remaking compression fittings, emergency repairs, and when to call a plumber.
A leaking pipe joint can waste water and damage floors and ceilings. Many leaks come from fittings that have loosened or worn. Some are a simple fix with a spanner; others need a plumber. This guide helps you work out which.
Step 1: stop the water
- If there's an isolation valve near the leak (a small valve with a screw slot), turn it 90 degrees with a flat screwdriver to stop the supply.
- Otherwise, turn off the water at your stopcock, usually under the kitchen sink, where the supply enters the home.
- For hot water and heating pipes, turn off the boiler too.
- Open a tap to drain residual water.
- Protect the area with towels and a bucket.
If water is near electrics, switch off the power at the consumer unit if safe.
Step 2: identify the joint
- Compression fitting: has nuts on each side of the fitting, tightened onto the pipe. Common under sinks and on valves.
- Push-fit fitting: usually plastic or metal, with a collar the pipe pushes into. No nuts.
- Soldered (capillary) joint: a smooth copper fitting with visible solder.
- Threaded joint: screwed fittings, often on taps, radiators and appliances.
Fixing a compression joint
- With the water off and the pipe dry, hold the fitting body with one spanner and tighten the nut with another by a quarter turn.
- Turn the water back on slowly and check.
- Don't overtighten: it can damage the olive (the brass ring inside) and make the leak worse.
- If it still leaks, the olive may need replacing. Undo the nut, cut off or remove the old olive, fit a new one, and retighten. Some people apply a little jointing compound to the olive.
Fixing a push-fit joint
Push-fit leaks are often caused by a pipe not inserted fully, a scored pipe end, or a missing pipe insert (needed for plastic pipe). With the water off, release the collar using the manufacturer's method, check the pipe end is clean and square, fit an insert if needed, and push it firmly home. Some push-fit fittings can't be reused; check the instructions.
Soldered joints
Leaking soldered joints usually need remaking with a blowtorch, which carries fire risks and needs skill. Most homeowners should call a plumber, or replace the joint with a compression or push-fit fitting if they're confident.
Threaded joints
Threaded joints may need resealing with PTFE tape or a thread sealant. Undo, clean the threads, wrap tape clockwise (in the direction of tightening), and retighten.
Emergency temporary repairs
- pipe repair clamps;
- self-amalgamating repair tape;
- epoxy putty for small leaks on pipes.
These are temporary; get a permanent repair soon.
When to call a plumber?
- leaks on soldered joints or inside walls and floors;
- leaks on gas pipes. Never attempt gas work: call the gas emergency line (0800 111 999) if you smell gas;
- leaks on the boiler or hot water cylinder;
- corroded pipes, or repeated leaks;
- if you can't stop the water.
Insurance
Escape of water is commonly covered by home insurance, but repairs to the leaking fitting itself often aren't. Take photos and contact your insurer promptly if there's damage.
Frequently asked questions
Can I use PTFE tape on compression fittings?
Not usually on the olive itself. Use it on threads, or jointing compound sparingly.
Why does a joint leak only when hot?
Expansion can open a slightly loose joint. Tighten carefully when cool.
Sources and further reading
Facts checked on 20 October 2026. Spotted an error? Tell us and we will correct it.