This is a common thing.
The pipe coming down the middle of the photograph is a flexi, a braided pipe that feeds a tap. Follow it down to where it is crimped into the nut and the trouble is plain to see. The braid has gone rusty brown, the strands at the bottom have frayed and come loose, and it was leaking at that joint. The valve it screws onto is crusted green, and the tiles behind are stained black along the grout and broken out around the pipe. The beige pipe beside it is the waste trap, the other half of what lives under a sink.
What a flexi is
Inside the braid is a rubber hose, and the hose carries the water. The woven steel round it holds the hose together and stops it swelling, and the nuts at each end are crimped onto both. It is the short bendable length that joins the fixed pipework in a wall or a floor to a tap or a cistern.
Where they go
Under kitchen taps, bath taps and basin taps, and on the cold feed to a toilet. Under baths, sinks, basins and toilets, in other words, which is most of the water fittings in a house, and that is why so many of these jobs come in.
Why the rust matters
Rust on a braid is the braid going.
The steel strands are what hold the hose in shape against the water inside it, and once they rust they give up one at a time, which is what the loose strands at the bottom of this one are. The hose then has less and less holding it, and the weakness shows first where the braid is crimped into the nut, because that is where the pipe bends and where any water that weeps out sits. A flexi in that state goes one of two ways. It weeps, slowly, into the back of a cupboard nobody looks in, and that is the black on these tiles. Or the hose splits, and then it is not a drip under a sink any more, it is the supply running into the cupboard until somebody turns it off, which is the burst our emergency page is there for. A flexi cannot be mended. There is no wrapping a frayed braid and no tightening a nut that is crimped on, so the answer to a rusted one is a new one, and any other flexi in the house that looks like this one is going the same way.
Changing one
It is a small job when the valve it hangs off still works. Water off at that valve, the old pipe out, and a new one in at the right length, so it is neither bent tight nor stretched, with the joints watched dry before the cupboard door shuts. A valve crusted like the one here is worth the same look, because it is the thing that has to close next time. Valves and short runs like this are the pipework side of what we do.
Water under a sink
Ring 07546 185778 and say where it is, under a sink, a basin, a bath or a toilet, and whether it is dripping or running.
