Stop a dripping compression joint by isolating the water, checking the olive, and retightening or renewing the joint correctly.
PL-01Protect the area and gather toolsLay an old towel or dust sheet under the joint to catch drips and protect flooring or cupboard shelves. Clear away anything stored nearby so you can see and reach the joint properly. Get two adjustable spanners, a bucket, kitchen roll, and a torch if the pipe is tucked away.
PL-02Isolate the water supplyTurn off the stopcock, usually under the kitchen sink, or the local isolation valve if the joint has one nearby. Open the lowest tap in the house, or the nearest tap if using a local valve, to drain the pipe and relieve pressure. Wait a few minutes and check the drip has stopped before you touch the joint.
PL-03Try a gentle retighten firstMany leaks are just a nut that has worked loose. Hold the fitting body still with one spanner and turn the nut clockwise a small amount with the other, no more than a quarter turn at a time. Turn the water back on briefly to test, then isolate it again if it still leaks.
PL-04Dismantle the joint if tightening doesn't fix itWith the water still off, unscrew the nut fully and slide it back to expose the olive. Note the order the parts come off in, since they go back on the same way. Keep the bucket and kitchen roll underneath to catch any water still in the pipe.
PL-05Inspect the olive and pipe endCheck the olive is not cracked, cut, or sitting at an angle instead of square on the pipe. Check the pipe end is round and smooth, not dented or scored where the olive grips it. If the pipe end is damaged, it will need cutting back to sound pipe with a pipe cutter before you reassemble.
PL-06Fit a new oliveA used olive rarely seals well a second time, so fit a new one even if the old one looks fine. Buy the correct size for your pipe, 15mm or 22mm are the two common sizes in a house. Slide the nut onto the pipe first, then the new olive with its wider face pointing towards the nut.
PL-07Reassemble and tighten to the correct amountPush the pipe fully home into the fitting body, then slide the olive and nut up to it. Hand-tighten the nut first, then use the two spanners to tighten a further one to one and a half turns past hand tight for a 15mm joint. Do not overtighten, as this can crack the olive or squeeze the pipe out of shape and cause a new leak.
PL-08Turn the water back on slowlyOpen the stopcock or isolation valve slowly rather than all at once, so any small leak shows up gently rather than as a spray. Watch the joint closely for a full minute. Check for drips at the nut and around the olive, not just underneath.
PL-09Test under normal useRun a tap or flush a toilet, whichever sends water through this pipe, to test the joint under real flow. Dry the joint fully with kitchen roll, then check it again after ten minutes and once more the next day. Small drips can take a while to show.
PL-10Tidy upDry the area fully and dispose of the old olive and any offcut of pipe. Put back anything you moved to reach the joint. If the pipe runs under a floor or in a damp cupboard, check for lingering moisture that could cause mould or rot later.
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