Replace an inset kitchen sink

Fit a new inset sink into your worktop, connecting waste and taps safely without leaks or damaging the worktop.

SK-01Turn off the water and clear the spaceTurn off both isolation valves under the sink if fitted, or turn off at the stopcock (usually under the kitchen sink itself, so check it before you start) if there are none. Open the tap to release pressure and let any water drain into a bowl. Clear everything out of the cupboard below and lay down towels to catch drips.

1 each · Bucket or bowl

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2 each · Old towels

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SK-02Disconnect the old tap and wasteUndo the flexi tap connectors from the isolation valves with an adjustable spanner, then disconnect the waste trap unions. If a waste disposal unit is fitted, switch it off at the socket and isolate the circuit at the consumer unit before touching any wiring. Have a bowl ready to catch the last bit of water sitting in the trap.

1 each · Adjustable spanner

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SK-03Free the old sink from the worktopRun a sharp knife or scraper around the old sealant bead to break the seal between the sink and worktop. Undo any clips holding the sink from underneath. Lift the sink out carefully — old ceramic or granite composite sinks are heavy, so get a second pair of hands if needed.

1 each · Sealant scraper or sharp knife

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SK-04Check the new sink fits the cutoutCompare the new sink's template or footprint against the existing cutout. If it needs enlarging, mark the new line carefully and cut with a jigsaw fitted with a fine blade suited to your worktop material — laminate, wood or stone composite each need a different blade. Before cutting, check there's nothing running behind the worktop edge, such as a socket cable dropping down from above.

1 each · Jigsaw

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1 each · Fine-tooth jigsaw blade (laminate/wood)

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SK-05Fit the tap and waste to the sink before it goes inIt's far easier to fit the tap, basket strainer waste, and overflow (if fitted) to the sink while it's sitting upside down on a workbench than once it's dropped into the worktop. Use plumber's putty or sealant under the tap base and waste flange, then tighten the fixing nuts from underneath — snug, not overtightened.

1 tub · Plumber's putty

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1 each · Basket strainer waste kit

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SK-06Seal and drop the sink into placeRun a neat, continuous bead of silicone sealant around the top edge of the cutout. Lower the sink in evenly and press down firmly all round so it beds into the sealant. Secure any underside clips per the sink's fitting instructions, then wipe away excess sealant with a damp cloth before it skins over.

1 tube · Kitchen and bathroom silicone sealant

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SK-07Reconnect the waste and water supplyConnect the waste pipe back to the trap, making sure joints are square and fully pushed home. Reconnect the tap's flexi tails to the isolation valves, wrapping PTFE tape on any threaded connections that aren't push-fit. If there's a waste disposal unit, reconnect the wiring only once you're sure the water side is sound and leak-free.

1 roll · PTFE tape

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SK-08Test for leaks and finish upTurn the water back on at the valves or stopcock and run the tap for a minute, checking under the sink at every joint for drips. Fill the sink and let it drain to test the waste and overflow together. Once you're happy it's watertight, tidy the cupboard and dispose of the old sink and any offcuts responsibly.

1 each · Kitchen roll or cloth

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