One leak on a sound pipe, or a pipe that is failing?
A supply pipe with one leak usually needs one repair rather than a water supply pipe replacement. If the pipe is plastic or copper in fair condition, cutting out the damaged piece and joining in a new one puts it right. Replacement is worth planning when the pipe is lead or iron, has been repaired before, or testing shows weak spots along its length.
Look at the supply pipe as a whole, not just the leak. A newer blue plastic pipe with a single leak is often sound either side of it. An old lead or galvanised pipe is a different matter, because one leak is often the first of several. These signs point towards a pipe that is wearing out:
It is lead, iron or galvanised steel
It has been repaired at least once before
Pressure at the taps has fallen slowly over the years
Testing finds more than one leak on the same run
It still loses water after a repair
It runs under ground you are about to build on or relay
What testing tells you about the rest of the pipe
A leak survey answers two questions: is water escaping, and where. Shut the stop tap with nothing running indoors, and a boundary meter will show whether the buried pipe is still taking water. Listening along the route with a ground microphone can pick up a second leak as well as the first. For faint leaks on plastic, tracer gas, a hydrogen and nitrogen mix, takes over.
There is a catch with old pipe. Once weak pipe has been tested or repaired, leaks can appear at other points along it, and any work on those is quoted separately. A second leak found that way still tells you something useful: how worn the pipe is, before you pay for more patches.
If leaks keep appearing on a lead or iron pipe, each repair means another hole, another wait without water and another bill. That is usually the point where owners stop patching and plan a replacement, using the test results to show where the weak spots are. Keep each report, so the pattern is on paper when you ask for quotes.
What changes the cost
Water supply pipe replacement cost depends more on the ground than on the pipe. Laying a new pipe under a lawn is a very different job from laying one under block paving, a concrete path, a conservatory or a tarmac drive that has to be made good afterwards. A single repair works the same way on a smaller scale: one hole rather than a trench.
Finding the leak is priced differently. We talk the job through by phone or email and fix the price before anything is booked. That price buys a set block of detection time, either half a working day or a whole one, and an early find does not cut it. Materials, and any parking fee or toll on the way, go on the bill at what they cost us. The repair gets its own quote. For the dig itself, these are what move the price most:
How long the run is from the boundary to the house
What covers it: lawn, gravel, paving, concrete or tarmac
How deep it is, and whether anyone knows its route
Room for a small digger, or hand digging only
Walls, trees or other services close to the line
Putting the surface back afterwards
A single repair: what to expect
A water supply pipe leak repair starts at the mark. Once the leak has been located from above ground and a second test agrees, we put a mark on the ground and photograph it. The hole is dug there, big enough to work in, the pipe is uncovered, and the damaged part is cut out and replaced. The water has to be off while the new joint is made, so fill a kettle and a few bottles first.
The mark is the right place to start, though a leak is never certain until the pipe is uncovered and the water can be seen coming out. Ask before work starts how the surface will be left and who will put it back. If your meter is outside, run the meter check again with everything off once the joint is done. A still meter means the repair is holding.
Our repairs are guaranteed for 3 months. That covers the new piece of pipe and the fittings that join it, and nothing beyond them, which is one more reason to think about the age of what is left. If the rest is old lead or iron, watch your bills, and glance at the meter every few weeks if it is outside.
Planning a full water supply pipe replacement
A full replacement is a larger job that needs planning. A new pipe, usually blue plastic, is laid from the boundary to the house, either along the old route or on a new one that avoids the drive or an extension. Some installers can pull a new pipe through the ground with much less digging than an open trench needs.
Get it quoted properly, with the route agreed in writing. Our written report helps whoever prices the work, because it sets out where the leak was, the methods we used, the readings and the photographs, so they can see where the trouble was found. Expect disruption along the route while the work goes on, and time without water while the new pipe is connected to the house.
Check with your insurer and your water company before work starts. Some home policies help with finding and reaching a leak but treat a pipe that has simply worn out differently, so read the wording. Your water company can tell you whether it needs to know about the work at the boundary, and what it knows about its own pipe there.
The boundary with the water company
Responsibility usually changes hands at the edge of your property. Up to that line, including the main in the street, it sits with the water company. From that line to the house, the supply pipe is normally the owner's to repair or replace. An indoor meter does not move the line, so the buried length outside still falls to the owner.
Leak policies differ between water companies. Some offer an allowance on a bill pushed up by a supply pipe leak once it is repaired, but the details are theirs to set, so ask yours before you choose between repair and replacement. Keep our report and your receipts together. If the fault proves to be on the company's side of the boundary, report it to them rather than digging.