Swap a leaking kitchen sink basket strainer for a new one, sealing it properly to stop drips for good.
SW-01Clear the cupboard and protect the areaEmpty the cupboard under the sink so you can work comfortably. Lay an old towel on the base and put a bucket or bowl under the trap to catch any water left in the pipe. Have a cloth to hand for drips.
SW-02Disconnect the waste trapLoosen the nuts on the trap under the sink by hand or with adjustable pliers. Slide the trap down and off the tailpiece of the strainer, letting any water drain into the bucket. Set the trap aside — you'll usually reuse it.
SW-03Remove the old strainerHold the strainer basket still from inside the sink with a screwdriver handle or similar, and undo the locknut underneath with pliers or a basin wrench. Once the locknut is off, push the whole strainer up and out through the sink hole.
SW-04Clean the sink holeScrape off all the old plumber's putty or silicone from around the hole in the sink, both on top and underneath. Wipe the area with a cloth and a little washing-up liquid so the new seal sticks properly. Old, hardened putty is the most common cause of leaks after a swap.
SW-05Fit the new strainerRoll plumber's putty into a thin sausage and press it around the underside of the new strainer's rim, or run a bead of silicone sealant instead — check what the kit recommends. Push the strainer down into the sink hole from above, pressing evenly so it seats flat.
SW-06Tighten from underneathFrom below, fit the rubber washer, then the metal washer, then the locknut onto the strainer's threaded body, in that order. Hold the strainer square from above and tighten the locknut with pliers or a basin wrench until firm — don't overtighten, as this can crack the sink or split the washer.
SW-07Reconnect the trapSlide the trap back onto the strainer's tailpiece and hand-tighten the nut, then give it a small turn with pliers to snug it up. If the joint looks worn, wrap a couple of turns of PTFE tape around the threads first.
SW-08Test for leaksRun the tap for a minute and check every joint — the sink rim, the strainer body, and both trap nuts — with a dry finger. Fill the sink and let it drain fully, then check again. Leave the bucket underneath for an hour and check once more, as slow leaks often show up later.
SW-09Tidy upWipe away any excess putty or sealant squeezed out around the sink rim while it's still soft. Dry the cupboard base, bin the old strainer and packaging, and put everything back under the sink.
Some links may earn us a small commission at no extra cost to you.