A water pipe usually leaks because a joint has loosened or worn, the pipe itself has been damaged or corroded, or movement has put strain on the pipework. The cause is not always where the water shows, so a leaking pipe often needs checking before the right repair can be chosen.
Knowing the likely causes can help you describe the problem and understand what a plumber may look at. It can also help you decide how quickly it needs attention.
Joints and Fittings
Many pipe leaks start at a joint, where two lengths of pipe meet or where a pipe connects to a valve, tap or appliance. Over time, seals and washers can wear, and some fittings can work loose, especially if the pipe moves or is knocked.
A joint that has been disturbed during other work, such as fitting a new kitchen, may also start to weep. Not every leak comes from a joint, though. Water can run along a pipe and drip from a lower point, so the drip is not always at the source.
Corrosion and Wear
Some types of pipe and fitting can corrode over time, depending on the material, the water and the conditions around the pipe. Corrosion may show as green or white staining, crusty deposits or rust around a fitting. In some cases it can lead to a small pinhole leak.
Staining on its own does not always mean a pipe is leaking now, but it is worth having checked, especially if it is getting worse.
Damage and Movement
Pipes can be damaged by a nail or screw, by building work, or by things stored against them in cupboards. Pipes that are not well supported can move each time water flows, which can put strain on joints and lead to leaks.
Frost can also damage pipes in cold areas such as lofts and garages. A pipe that has frozen may develop a crack that leaks slowly rather than bursting outright.
Is It Definitely the Pipe?
Water near pipework does not always come from the pipe itself. It could be condensation on a cold pipe, a leak from a waste pipe, a worn seal on a tap or appliance, or water from outside the building.
If you can see a drip, it may help to dry the pipe and joints with a cloth and watch where the water reappears. If water is near electrics, keep clear and seek appropriate help. If the leak is steady, closing a nearby isolating valve, or the stopcock if it turns normally, may stop it while you wait.
Our page on leaking pipe repair in Poole explains how leaking pipes are assessed and repaired once the source has been found.
If you have spotted water around a pipe at your Poole home or business, a plumber can check the cause and explain the repair options.