Before anyone arrives: ten minutes that decide the damage
The size of the bill is set in the first ten minutes, not by how fast an engineer drives. Do these in this order.
- Stop tap off. Usually under the kitchen sink, sometimes in a hall cupboard, under the stairs, or in a downstairs loo. Turn it clockwise until it stops. If it spins without biting or will not shut fully, go to the outside stop tap at the boundary, under a small metal or plastic cover in the path.
- Open the kitchen cold tap, then every other cold tap. This is the step people skip. Closing the stop tap does not empty the rising main and the pipework above it — that water keeps leaving through the split until it has drained. Opening the taps drains it into the sink instead of into your ceiling. Flush the toilets too.
- Turn the heating off at the programmer. A sealed heating system is a closed loop. It holds its own water, and the stop tap does nothing to it. If the leak is on a heating pipe — a warm wet patch, or water that keeps coming after the cold system has drained — shut both valves on the nearest radiator, or drain the circuit down.
- Electrics, if water is anywhere near a fitting. Water running down through a ceiling finds downlights and ceiling roses first. If it is dripping from a light, running near a socket, or tracking down a wall with switches on it, kill the consumer unit. Do not stand in water to reach it, and do not put your hand into a wet ceiling void.
- Photograph everything before you mop. The clean-up destroys the evidence your insurer will want. Thirty seconds of video of where the water is and what it has reached is worth more than any description you write later.
The full sequence, including what to do if the water is coming from the flat above, is in what to do if a pipe bursts. If the pipe is accessible and you want to hold it until someone gets there, how to stop a leaking pipe temporarily covers what actually works and for how long.
What an emergency repair is really buying you
An emergency pipe repair has one job: stop the loss and get the water back on. That is not the same as finishing the job.
By the time an engineer leaves, you should have a building that is no longer taking on water and taps that work. What you will not have is a floor, a wall or a ceiling that looks like it did yesterday, and you may not have a permanent pipe.
A permanent remake needs the pipe dry, the run exposed properly and the void opened enough to work in — and opening a ceiling at midnight in an occupied flat, with the water still tracking, makes a bigger mess than waiting until morning. So the honest description of most emergency pipe work is a two-visit job: safe and dry tonight, permanent and tidy in daylight.
The three things that actually get done after dark
A repair clamp
A proper pipe repair clamp — a steel or brass shell with a rubber liner, bolted over the split — holds mains pressure on an accessible straight length of pipe. It is a real fix in the sense that it stops water, and it will often hold for months. It is not a permanent one: it depends on a rubber seal sitting on corroded metal, and the pipe around it is usually the same age and the same condition as the piece that failed.
A cut-out and a slip coupling
Where the pipe can be reached and the water can be drained locally, the split section is cut out and a slip coupling goes in — a compression or push-fit fitting that closes the gap without needing extra pipe length. No flame, which matters in a flat with a wet ceiling and a fire alarm panel that answers to a managing agent. This is a permanent repair, and where the access allows it, it is done on the night.
Freezing the pipe
A pipe freeze kit puts a plug of ice into a full pipe either side of the damage, so a section can be cut out without draining the whole system. It saves an hour of drain-down on a big Victorian conversion. Its limits are worth knowing: it needs the water static, it is unreliable on fast-flowing mains, and it works far better on copper and steel than on plastic.
The material changes the repair
| Pipe | Same-night repair | What it really needs |
|---|
| Copper | Clamp, or cut out and slip coupling | The failed section replaced. If it is pinholing, the rest of that run is next. |
| Plastic push-fit | Often a genuine permanent fix on the night | Usually nothing more, if the insert and the pipe support are right. |
| Lead | Rarely. Clamps do not seat reliably on lead. | Replacement in MDPE or copper, planned, not improvised. |
Copper
Copper fails in two different ways, and they need different answers. A split from freezing is a single event: cut it out, put a coupling in, done. Pinholing from internal corrosion is not a single event — it is the pipe telling you it is at the end of its life, and patching one hole in a run that is producing them means you will be back. It changes what the second visit is: one joint, or one length re-run.
One detail that is not optional: soldered joints on drinking water pipework must be made with lead-free solder. WaterSafe has been campaigning on exactly this, because a number of installers still carry leaded solder. If a joint is being soldered in your kitchen at midnight, it is a fair question to ask.
Plastic push-fit
Push-fit leaks are usually assembly faults rather than pipe faults: a missing insert, a pipe cut at an angle, a fitting not pushed fully home, or a run left unsupported so it works itself loose. That is good news at 2am, because remaking it properly is often the whole repair and it needs no heat, no drain-down of the building, and about ten minutes. The failure modes are set out in more detail under pipework repair and replacement.
Lead
Lead is the one where the honest answer is usually "not tonight". It is soft, it deforms under a clamp rather than sealing against one, and joining to it is a specialist skill — a wiped joint or a lead-lock fitting, not something improvised from a van. It is also the one place where the repair decision is about water quality as well as water loss: lead pipe is what water companies, Thames Water included, actively want replaced rather than patched, and the sensible outcome of a lead leak is a new MDPE or copper run.
There is a boundary question too. If the leaking lead pipe runs between the street and your boundary stopcock, that is your water company's pipe and the call goes to them first. From the boundary to the house it is yours, and that work falls under the Water Supply (Water Fittings) Regulations 1999 — another reason it is planned rather than bodged in the dark.
What genuinely has to wait
- Finding a leak nobody can see. Tracing a hidden loss means isolating, pressure-testing, then thermal imaging and tracer gas on a drained circuit. Acoustic work needs a quiet building, which a night call can sometimes give you and a busy road can ruin.
- Opening a floor or a ceiling properly. Controlled access means dust sheets, a clean cut and somewhere for the debris. Done in a hurry it costs more to put right than the pipe did.
- Drying. Plaster, screed and joinery hold water for weeks. Skimming over a wet substrate traps it, and it comes back as blown plaster or a lifted floor months later.
- Reinstatement. Boarding, skimming, tiling and decorating are daytime trades. Our own handymen and builders close the hole back up, but that happens after the drying, not before.
- Excavation. A split on a buried supply pipe under a driveway is a daylight job with a digger or a moling rig.
Is it an emergency? A quick way to decide
Not every leaking pipe needs someone tonight. The question is whether water is still going somewhere it will do damage once the stop tap is off.
| What you are seeing | Tonight or tomorrow? |
|---|
| Water still pouring after the stop tap is off and the taps have drained | Tonight. It is likely a heating pipe or the stop tap is not holding. |
| Water coming through a ceiling near lights or a consumer unit | Tonight, with the power off at the board. |
| No water at all and a household that cannot go without it | Tonight. Getting the supply back is the job. |
| A split pipe that stopped once you isolated it | Tomorrow. Leave it off. |
| A slow drip into a bowl from an accessible joint | Tomorrow, with a towel and the isolating valve closed. |
| A damp patch that has been growing for days | A repair to book, not an emergency. It needs the leak found and fixed, which is daylight work. |
If the answer is tonight, call and tell us what the pipe is made of if you can see it, whether the water has stopped, and whether it is coming through a ceiling. That tells us what to bring. For a split or burst pipe the service page is burst pipe repair; for anything else that will not wait, emergency leak repair.
What it costs, and when not to call us
£150 per hour, agreed before we set off. No call-out fee and no out-of-hours uplift — the rate at 3am is the rate at 3pm. If we are looking for a hidden leak and we do not find it, you do not pay for the time we spent looking. Nobody can give you a final figure down the phone, because it is set by how long the work takes and what is behind the wall. The full breakdown is on pricing.
Some things are not our job, and it is cheaper for you to know now. A leak before your boundary stopcock belongs to the water company and they attend free. Anything inside a boiler casing, or any work on gas pipework, is a Gas Safe engineer's job. A communal riser or a leak in the flat above belongs to the freeholder or the managing agent — call them, not a contractor you will have to pay.
And if the water has already stopped on its own, you almost certainly do not need anyone at midnight. Leave the stop tap off, get some sleep, and call in the morning. A leak that has stopped is not an emergency; it is a repair with a date on it.
