Leaking pipe joint? We remake the connection properly, not just tighten it

Why joints leak

Every joint is a compromise between two materials trying to be watertight, and each type fails in its own way. Compression fittings rely on an olive being crushed evenly onto a clean pipe; a scored pipe, an overtightened nut or a cheap olive will weep. Soldered joints fail when the pipe was wet, dirty or overheated, leaving a void in the solder that holds for months and then does not. Push-fit fittings leak when the pipe was not cut square, was not pushed fully home, or has no insert, so the plastic pipe slowly creeps out under pressure. Threaded joints on older steel pipe corrode and weep at the root of the thread. Add movement, vibration from a pump, or the expansion and contraction of hot water, and a joint that was marginal from day one will start to show.

Why a dripping joint is not a small problem

A drip is small only while it is visible. Water from a joint under a sink runs along the pipe or the back of the cabinet and rots the carcass from underneath, where you will not see it until the board swells. On a heating circuit, a weeping joint loses pressure, so the boiler cycles, radiators go cold at the top and the system pulls in fresh water that adds air and corrosion. Behind a wall or under a floor, a joint that drips steadily will saturate plaster and timber over weeks. Tightening a leaking compression nut often distorts the olive further, turning a weep into a spray. Left alone, a joint that weeps under a pressurised system rarely improves.

How we find the joint at fault

We dry the area and watch, because a drip rarely falls from where it starts. Water tracks along the underside of a pipe and appears at the lowest point, so we follow the line of the pipe rather than the drip. We check the obvious suspects first: taps and their tails, appliance connections, radiator valves, pump connections and any recently disturbed pipework. Where the joint is hidden, we isolate sections and pressure test, or use moisture readings to narrow the area before opening anything. We check the joint type and the condition of the pipe at that point, because that determines whether remaking it will hold or whether the pipe needs renewing around it.

How we remake the joint

The section is isolated and drained. We cut back and clean the pipe properly, removing old jointing compound, scale and any burr, and check it is round and unscored. The old olive, washer or fitting is discarded rather than reused, because a crushed olive will not seal twice. Compression joints get a new olive and are tightened to the right point rather than as hard as possible. Soldered joints are remade dry with the correct flux and enough heat. Push-fit gets a square cut, a proper insert and a full push home, with the grab ring checked. Threaded joints are remade with appropriate tape or paste. Then the joint is tested under working pressure, with hot water run through where relevant, and the area left dry.

Keeping joints sound

Support pipework so joints are not carrying weight or strain, and clip runs at sensible intervals. Avoid mixing fitting types on one connection, and do not reuse olives or washers after a disturbance. If you drain the system for any reason, refill slowly and check every joint afterwards. Keep inhibitor in heating systems at the right strength, because corrosion inside the pipe is what eventually kills threaded and soldered joints. When you have work done, ask for the joints to be tested before the pipework is boxed in, and photograph them while they are accessible.

When to call us

Call if a joint is dripping rather than damp, if it is on a heating circuit and the pressure keeps dropping, if the pipe shows green crusting or white scale at the joint, or if the joint is behind a wall, under a floor or above a ceiling. Call also if you have already tightened it once and it still weeps, or if the pipe is old steel and the thread is corroded. A joint that is merely damp with no drip can usually be booked in rather than treated as an emergency.

Book a call-out

Describe where the joint is and what it connects, and send a photo if it is easy to reach; that helps us arrive with the right fittings. If opening a wall or floor is needed, or the surrounding pipe turns out to be too far gone to remake, we will explain the options and price before going ahead. Book a leaking pipe joint repair and we will stop the drip at the source.