DIY GUIDE · PLUMBING & HEATING

How to fix a dripping tap or a leaking joint yourself
Half an hour to two hours. £2–£21 for washers, olives or a cartridge.

A drip has one cause and one part. Isolate, find it, replace it, test — and stop where the pipe disappears into the wall.

DIFFICULTY
Easy
part of the job only
TIME
30 min – 2 hours
a washer takes minutes once the tap is apart; a seized old tap or joint takes longer
MATERIALS
£2–£21
a pack of washers or olives costs pennies; a pair of ceramic cartridges is the dearest part
A PRO CHARGES
£80–£350
typically £150
  • Every step, start to finish
  • Checked October 2026 — sources at the end
  • Honest about when to call a pro

FIRST, THE HONEST ANSWER

Do it yourself, or get a repairer?

Do it yourself if…

  • You can see the leak and reach it, under a sink, at a tap, at a valve or a trap
  • There is an isolating valve on that pipe, or the stopcock turns off fully
  • The leaking part is a tap, a compression joint, a valve gland or a plastic trap
  • Nothing is wet that should not be — no ceiling stain, no damp wall

Get a pro if…

  • The leak is inside a wall, under a floor or above a ceiling
  • A soldered joint has failed, or the pipe itself is corroded or pitted
  • The leak is on a heating pipe or a boiler, or on a pressurised hot water cylinder
  • The stopcock will not shut off, or the leak keeps returning after a repair

Safety first

  • Isolate the water before you undo anything: a valve with a screwdriver slot, or the stopcock. Then open the tap to let the pressure go. A nut undone on a live pipe sprays at mains pressure.
  • Turn off the boiler or the immersion heater before working on a hot pipe or tap, and let the water run cold. Hot water scalds.
  • If water has reached a light fitting, a socket or an appliance, switch off at the consumer unit first. HSE's electrical guidance is always to isolate before you go near.
  • Wear safety glasses when working under a sink or basin; grit and old water fall towards your face as nuts come loose.
  • Leave gas pipes alone. A yellow-labelled pipe or one running from the meter is gas, and any work on it is for a Gas Safe registered engineer.

Stop here: Stop here: hidden leaks, heating circuits, cylinders and gas

Replacing a washer, an olive or a cartridge on an existing fitting is maintenance. Moving or adding pipework is installing water fittings, which must meet the 1999 Water Fittings Regulations in England and Wales, the Scottish Water byelaws in Scotland or Northern Ireland's 2009 Water Fittings Regulations. A leak on an unvented hot water cylinder falls under requirement G3, with England's Approved Document G and the other nations' building regulations to the same effect, and is for an unvented-qualified installer only. A boiler and its gas pipework are gas work, which the 1998 Gas Safety (Installation and Use) Regulations restrict to Gas Safe registered engineers in Great Britain, as the 2004 Regulations do in Northern Ireland. How to hire a leak repair plumber →

MATERIALCOVERAGEFOR THIS JOB
Tap washersMatched to the tap sizeA mixed pack
Ceramic cartridgesMatched to the tap's spline count and lengthA pair, or the mixer maker's single cartridge
Compression olivesMatched to the pipe sizeA pack
PTFE tapeOnly for tapered male threads, never on an oliveOne roll

What a drip costs

Water wasted = drips per minute × the volume of a drip × minutes in a day. A tap that fills a 100 ml cup in ten minutes wastes 10 ml × 1,440 minutes = 14.4 litres a day.

On a water meter that is on every bill; on any supply it is the drip that stains the basin and furs the waste.

Rubber-washer tap or ceramic-disc tap

Turn the handle. If it turns several full turns from off to fully on and you feel it squeeze shut, it has a rubber washer on a jumper inside. If it goes from off to on in a quarter or half turn, it has a ceramic disc cartridge. A washer tap that drips needs a new washer. A ceramic tap that drips needs its cartridge cleaned of grit or scale, or replaced.

Single-lever mixers

A single-lever mixer has one cartridge that controls both flow and temperature. The tap maker's maintenance page shows how to take the handle off, remove the cartridge retaining nut, lift the cartridge out and clean it under cold water; if that does not stop the drip, the cartridge is replaced with the maker's own part. Note the make and model before you buy.

Olives for compression joints

A compression joint seals on a brass ring, the olive, squeezed onto the pipe by the nut. A weeping joint often needs only a small extra turn. If it was over-tightened or disturbed, the olive is distorted and must be replaced. The fitting maker's guide we checked warns that over-tightening weakens both the nut and the olive; buy a pack of the right size.

Thread sealing: tape or none

Compression olives never take PTFE tape. Tapered male threads, such as a fitting screwed into a boiler or a valve body, take a few turns of PTFE tape or a jointing compound. Parallel threads on tank connectors seal on a washer instead. The same fitting maker spells out that difference.

Fibre and rubber washers

Tap connectors, cistern connectors and washing machine hoses seal on flat fibre or rubber washers. Flattened, hardened or split washers drip. Buy a mixed pack and match the size and thickness of the old one.

Take the old part with you to the shop; tap cartridges in particular vary by make.
A drip that comes back days after a new washer usually means a worn seat inside the tap, not a bad washer.

THE PART THAT DECIDES THE FINISH

Before you start — where the water is coming from

Dry everything, then watch. The first place you see a bead of water is where the leak starts; water runs downhill and appears lower than its source. Match it to one of these.

Drip from the tap spout

A worn washer or a gritty cartridge.

  1. Close the isolating valve under the basin or sink, or the stopcock
  2. Open the tap fully to drain it, and put the plug in so small parts cannot go down
  3. Find how the handle comes off: a cap and a screw, or a grub screw under the lever
  4. Lay a towel in the sink to protect the enamel from dropped tools
Water round the tap handle or spindle

A worn gland or O-ring, not the washer.

  1. Isolate and drain the tap as above
  2. On an old washer tap, a gland nut under the handle can sometimes be nipped up a quarter turn to stop it
  3. On a ceramic tap or a mixer, the cartridge's O-rings are the fix
  4. Clean and smear new O-rings with silicone grease before fitting
A bead on a compression nut

Under a sink, at a valve or on an exposed pipe.

  1. Dry it, then watch to be sure the water starts at the nut and not above it
  2. Try a quarter turn first, with a second spanner on the fitting body
  3. If it still weeps, isolate, undo, and fit a new olive
  4. Check the pipe is round and clean where the olive sits
Drip from a trap or waste

Plastic waste pipe under a sink, basin or bath.

  1. No water to isolate — just stop using the fitting
  2. Put a bowl under the trap
  3. Check each plastic nut is hand tight; many drips stop with that
  4. If not, undo and inspect the washer for folds, flats or splits
Damp you cannot trace

A stain on a ceiling, a wet patch on a wall, or a meter that moves with everything off.

  1. This is not a visible leak and this guide is not the fix
  2. Read the leak-finding guide to narrow it down
  3. Do not cut into walls or lift boards over hidden pipes and cables
  4. Call a plumber if you cannot find a visible source

THE JOB

How to fix the leak

  1. Set up: isolate the water and find your case

    10 min

    Read the cards above and decide which leak you have. Turn the isolating valve on that pipe a quarter turn so its slot sits across the pipe, or turn off the stopcock. Open the tap to let the pressure out and drain the pipe. Turn off the boiler or immersion heater for a hot pipe. Plug the sink and lay a towel in it.

    • Wait a minute with the tap open to prove the water is off
    • Photograph the tap or joint before you take it apart
    • Put a bowl under any joint you will open

    Mistake to avoid: Starting on a tap with the water still on because the isolating valve was half turned. The spindle comes out and the tap fires a jet at the ceiling.

  2. Take the tap apart

    15 min

    This is the prep from your card above. Prise off the handle cap, undo the screw or grub screw beneath, and pull the handle off. Under it is a shroud, then the headgear or cartridge with a large hexagon nut. Hold the tap body still with one hand, or with a cloth and grips, and undo the headgear nut anticlockwise with a spanner. Lift the headgear or cartridge out.

    • Keep the parts in order on a towel as they come off
    • If the headgear is stuck, a little penetrating oil and patience beat force
    • Never brace the spanner against the basin; the tap twists and the basin cracks

    Mistake to avoid: Undoing the headgear without holding the tap body. The whole tap turns on the basin, breaks its seal, and the supply connection underneath starts leaking too.

  3. Replace the washer or clean the cartridge

    15 min

    On a washer tap, the washer is on the bottom of the jumper, held by a small nut or pushed on. Remove it, fit a new one of the same size, and refit. On a ceramic cartridge, rinse it under cold water to clear grit or scale, as the tap maker's maintenance page describes, and look at the discs and the seal at the bottom. If they are chipped or the drip persists, fit a new cartridge from the same maker.

    • Look into the tap body at the seat; a pitted seat chews new washers
    • Match a replacement cartridge's spline count and length exactly
    • Smear new O-rings with silicone grease before refitting

    Mistake to avoid: Fitting a universal cartridge that is a few millimetres different. The handle no longer turns fully off, or the tap drips from a new place.

  4. Reassemble and test the tap

    10 min

    Refit the headgear or cartridge and tighten its nut firmly, holding the tap body still. Refit the shroud, the handle and the cap. Turn the tap off, then open the isolating valve slowly and watch the spout and the base. Run the tap on and off several times, then leave it off and watch for drips for a few minutes.

    • Ceramic cartridges need only firm tightening; over-tightening cracks the discs
    • A short drip after closing is normal for a moment while water drains from the spout
    • Check under the basin too; disturbing the tap can disturb its connector

    Mistake to avoid: Cranking a ceramic cartridge down hard. The discs crack and the tap that dripped now runs.

  5. Fix a weeping compression joint

    20 min

    Dry the joint and confirm it is the source. Put one spanner on the fitting body and one on the nut, and turn the nut clockwise a quarter of a turn. Dry it and watch. If it still weeps, isolate the water, undo the nut, and look at the olive. A distorted, cut or doubled-up olive must be replaced: cut it off with a junior hacksaw across the olive only, taking care not to cut the pipe, fit a new nut and olive, push the pipe to the stop and tighten.

    • Always two spanners, so the fitting does not twist on the pipe
    • A new olive on copper goes about a turn and a quarter past hand tight on small sizes, by the fitting maker's guide
    • No PTFE tape on the olive, ever

    Mistake to avoid: Tightening and tightening a weeping joint. A crushed olive never reseals, and the nut can split.

  6. Stop a valve weeping at its spindle

    15 min

    Isolating valves and old stopcocks can weep where the spindle comes out. On a stopcock, the small gland nut under the head can usually be nipped up an eighth to a quarter turn to compress the packing. On a modern isolating valve with an O-ring spindle, the cure is a new valve, fitted like any compression joint.

    • Turn the stopcock fully on and back a quarter turn afterwards so it does not seize open
    • A weeping slot-type isolating valve is cheap; replace it rather than nursing it
    • Exercise every valve twice a year so they do not seize

    Mistake to avoid: Over-tightening the gland on a stopcock. It then will not turn at all, which is the worst state for a stopcock to be in.

  7. Fix a dripping trap

    15 min

    Put a bowl underneath. Undo the dripping nut by hand, take out the washer and look at it. A folded washer can be reseated; a flattened or split one needs replacing. Clean the threads and the pipe end, reseat the washer, and do the nut up hand tight. Fill the basin or sink and empty it to test under load.

    • Plastic trap nuts are hand tight; grips crack them
    • No tape or sealant on plastic waste threads; the washer seals
    • Check the trap is not pulled up under strain; a strained joint will always drip

    Mistake to avoid: Wrapping a dripping trap thread in PTFE tape. The washer then cannot seat and the drip gets worse.

  8. Test, then check the next day

    15 min

    Turn the water back on slowly. Hold a dry tissue under every joint you touched and watch for several minutes. Run the tap or the fitting at full flow. Leave a sheet of kitchen roll under the work overnight. A dry sheet in the morning is the result you want.

    • Turn the boiler back on once the hot side is dry
    • A drip that returns within days on a washer tap means a worn seat
    • Keep spare washers and olives in a labelled box

    Mistake to avoid: Declaring it fixed after one look. Joints that are slightly short of tight show their weep over hours, not seconds.

The mistakes that show

  • Working on a tap with the water not fully isolated
  • Using one spanner and twisting the pipe or tap body
  • Putting PTFE tape on compression olives or plastic trap threads
  • Over-tightening ceramic cartridges or compression nuts
  • Fitting a cartridge that is nearly the right size

Stop here and get a plumber

  • The leak is inside a wall, under a floor or above a ceiling
  • A soldered joint has failed, or the pipe is corroded or pitted
  • The leak is on a heating pipe, the boiler, or a pressurised hot water cylinder
  • The same joint or tap keeps leaking after a careful repair
How to hire a leak repair plumber →

Tap still dripping after a new washerThe seat inside the tap body is worn or pitted. A tap reseating tool can recut it, or a seat-and-washer kit covers it; otherwise the tap needs replacing.
Ceramic tap drippingGrit or scale between the discs. Isolate, remove the cartridge, rinse it under cold water and refit. If the discs are chipped, fit a matching new cartridge.
Water round the base of the tap handleThe spindle O-ring or gland is worn, not the washer. Replace the O-rings on the headgear or cartridge, greased with silicone grease.
Compression joint weeping after tighteningThe olive is crushed or the pipe is oval. Isolate, cut off the old olive, check the pipe end, and fit a new one.
Isolating valve leaking at the slotThe spindle O-ring has failed. Replace the valve.
Stopcock leaking at the topThe gland packing has dried. Nip the small gland nut a fraction; if it still weeps, a plumber can repack or replace it.
Trap dripping at the nutThe washer is folded or flattened, or the trap is strained. Reseat or replace the washer, hand tight, with the trap lined up.
Water under the sink but every joint looks dryThe leak is above: the tap's base seal, the sink's waste seal, or splash running down the back. Dry everything and run water one fitting at a time.

WHAT YOU SAVE

What it costs to do it yourself

Tap washers, pack£1–£3
Compression olives, pack£2–£3
PTFE tape£1–£3
Ceramic tap cartridges, pair£6–£21
Total, one repair£2–£21
DIY total£2–£21
A leak repair plumber charges per job
LOW
£80
TYPICAL
£150
HIGH
£350
Leak Repair price guide →

Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.

Against a plumber's guide price for leak repair, the part costs pennies or a few pounds; the plumber's fee is for the visit, and for the leaks you cannot see.

RATHER NOT?

Leak repair plumbers near you, with prices shown

The ones who cover your area, nearest first, with one score from every review. No account needed to look.

Or post the job free and let them come to you.

Keep a spares box

A labelled box with washers, olives, PTFE tape, silicone grease and the cartridge make written on the lid. The next drip is a ten-minute job.

Exercise the valves

Turn every isolating valve and the stopcock off and on twice a year so they work when you need them.

Dispose of the old parts

Rubber washers and plastic parts go in general waste; brass olives, nuts and old taps go to the metals container at your council's household waste recycling centre. Find yours on the council website or the recycling pages for your nation.

Watch for the return

Leave kitchen roll under the repair for a week. A drip that comes back tells you the seat or the pipe, not the part, is the problem.

Fixing a dripping tap or a weeping joint: questions people ask

Isolate the water, take the handle off and remove the headgear or cartridge. On a washer tap, fit a new washer; on a ceramic tap, rinse the cartridge or replace it with a matching one. Reassemble and test.

Only if there is no isolating valve under the tap. Most modern taps have one, turned with a flat screwdriver.

Try a quarter turn with two spanners. If it still weeps, isolate, undo it, cut off the old olive, and fit a new one. Never add PTFE tape to the olive.

Only on tapered male threads. Compression olives and plastic trap threads seal without it, and tape stops them seating properly.

The seat inside the tap is worn, so the new washer has nothing smooth to close against. Reseat it or replace the tap.

Locufy's UK price guide puts leak repair at £80–£350 per job, typically £150 — the same three figures as the strip at the top of this page.

MORE GUIDES

More DIY guides

Finding a hidden water leakReplacing a kitchen mixer tap like for likeStopping a burst pipe and repairing an exposed sectionReplacing a basin waste and bottle trapDoing the small plumbing jobsHandling a plumbing emergency until help arrivesBleeding radiators and re-pressurisingUnblocking a sink, bath, toilet or outside drain
All 90 DIY guides →How to hire a leak repair plumber →Leak Repair price guide →Leak repair plumbers on Locufy →

Sources — checked October 2026

  1. Bristan — sink mixer installation and maintenance instructions: cartridge removal and cleaning
  2. Flowflex — compression fittings technical data and installation instructions: tightening, PTFE and threads
  3. HSE — electrical safety: frequently asked questions
  4. HSE — domestic gas safety: frequently asked questions
  5. Water Supply (Water Fittings) Regulations 1999, regulation 5
  6. Water Supply (Water Fittings) (Scotland) Byelaws Extension Order 2024
  7. Water Supply (Water Fittings) Regulations (Northern Ireland) 2009
  8. gov.uk — Approved Document G: sanitation, hot water safety and water efficiency (England)
  9. Gas Safety (Installation and Use) Regulations 1998, regulation 3
  10. Gas Safety (Installation and Use) Regulations (Northern Ireland) 2004, regulation 3
  11. gov.uk — recycling collections: find your council (England and Wales)
  12. mygov.scot — find your council's recycling centre (Scotland)
  13. nidirect — recycling and reusing (Northern Ireland)
  14. B&Q — price check: tap washers
  15. B&Q — price check: compression olives
  16. B&Q — price check: PTFE tape
  17. B&Q — price check: tap cartridges