What we actually do
A leak repair is three decisions, made in this order once the pipe is exposed: repair it, re-run it, or replace it.
Repair means cutting out the failed length and joining new pipe in. On copper that is a soldered capillary joint where the position is dry enough to get heat into it, or a press-fit or compression coupler where it is not. On plastic push-fit it is a new length with proper inserts at each end. This is right when the pipe either side is sound and the failure was a one-off: a nail through it, a nicked loop, a joint that was never made properly.
Re-run means abandoning the buried run and taking the pipe by a different route. We do this when the existing position is the problem — pipe laid directly into screed with no sleeve, a run under a solid floor with joints buried in it, a line under a slab where any future failure would mean the same excavation again. A re-run through a service void, a boxed corner or an accessible floor is more work today and enormously less work the next time anything goes wrong.
Replace means the whole circuit or the whole supply: a lead supply pipe swapped for MDPE, a corroded microbore heating leg re-piped, a bathroom's hot and cold re-run after the third pinhole in two years. When a pipe has failed twice in the same run, the third failure is already on its way, and patching it again is money spent on delay.
How the visit runs
- The leak is located first, properly. We do not open floors to look. The run is pressure tested, then traced with acoustic, thermal, moisture mapping or tracer gas depending on the pipe material and the floor build-up.
- Isolate and drain. The smallest section that can be isolated is isolated, so the rest of the property keeps water where possible. In flats with no local isolation valves, fitting one as part of the job is often the single most useful thing we do that day.
- Open at the marked point. Boards lifted, a tile removed, a plasterboard cut, screed broken out — to the size the repair needs and no larger. On tiled floors we will ask whether you have spares before anything comes up.
- Expose and show you the failure. You see the pinhole, the split, the dry joint or the screw through the pipe. Nobody should be asked to pay for a repair they were never shown the reason for.
- Repair, re-run or replace, and then pressure test the section again before anything is closed.
- Dry, then reinstate. Wet screed and saturated joists are closed up only once they read dry, which is the step that most often gets skipped by others and is the reason floors cup and plaster blooms three months later.
- Make good. Screed, floor finish, plaster, tiling and decoration — our own reinstatement team, not a builder you have to find.
The four materials, and how each one fails
Copper
Still the dominant material in London housing stock, in 15mm and 22mm for most domestic runs and microbore on some 1970s and 1980s heating systems. Copper fails three ways. Pinhole corrosion from the inside, often where flux was never flushed out after installation, or where a system has been repeatedly topped up with fresh oxygenated water. Erosion at tight bends on a pump-driven circuit. And mechanical damage: a fixing through a pipe under laminate is one of the most common repairs we do.
MDPE
The blue plastic pipe used for underground water supply, typically 25mm to a house and 32mm where the run is long. It fails at joints far more often than along its length — a compression fitting tightened onto an unsupported pipe end, or a poor adaptor where new MDPE was married to old lead or alkathene. Covered in more depth on mains and supply pipe repair.
Plastic push-fit
Hep2O, Speedfit and similar barrier pipe, everywhere in refurbished flats because it is fast to install. Two classic failures: the pipe insert left out, so the joint holds on test and weeps under thermal movement; and the pipe left unsupported over a long span so it sags and stresses the fittings. Push-fit also damps sound, which is why a plastic leak often has to be found with gas rather than by listening.
Lead
Common in pre-war London, mostly on the incoming supply and occasionally on internal runs in unmodernised property. Lead fails by splitting where it has been work-hardened at a bend, or at the wiped joint where someone once married it to copper. We do not patch lead supply pipes as a long-term answer. Where we find one we will price replacing the run in MDPE, because a patched lead pipe is a repeat visit and a lead pipe is not something to keep in a drinking water supply. WaterSafe sets out why on lead pipework in domestic supplies.
What we most often find in London property
- A screw or nail driven through a pipe under laminate, engineered board or a newly fitted carpet gripper.
- Compression joints buried in screed or behind a tiled wall, weeping a quarter of a turn short of tight.
- Copper laid straight into screed with no sleeve or lagging, worn through by its own expansion over ten winters.
- Push-fit joints made without inserts during a fast flat refurbishment.
- Microbore heating legs silted and corroded, where one pinhole is the first of several.
- Old lead supply pipe joined to newer MDPE with a fitting that was never designed for the pairing.
- Soldered joints made on a pipe that could not be fully drained, so the solder never took properly and the joint held for two years.
Why we insist on doing the making good as well
Most London leak firms are detection businesses. They find the leak, hand you a report, and leave. You then hire a plumber for the repair and a builder for the floor, and when the reinstated screed cracks or the new boards cup, each of the three tells you it was one of the others. It is the most common complaint in this trade and it is entirely structural: nobody owns the whole job.
One company that traces, repairs and reinstates is one point of responsibility. It also means the repair is made with the reinstatement in mind — a joint positioned where it can be reached again, an access panel left where a future engineer will need one, a floor opened in a way that can be closed invisibly rather than the fastest way to reach the pipe.
When you do not need us
A dripping tap, a loose compression nut under a sink you can reach, or a washing machine hose you can hand-tighten are not pipework repairs. Turn off the isolating valve and try it yourself first — a leaking pipe under the sink is often a nut that has vibrated loose. If the pipe itself is split, or the leak is behind a wall, under a floor or above a ceiling, that is when to call.
What it costs
Charged at our hourly rate, fixed before we attend, plus materials. The rate does not rise for an evening visit or an awkward property. The total depends on the length of the run, how much has to come up to reach it and what finish has to be matched when it goes back, so we price the work in front of you once the pipe is exposed rather than quoting a figure down the phone we would have to revise. Terms in full on the pricing page.
