Renovation guides

How to replace a kitchen sink

Draft guide written from standard practice, not yet reviewed by a licensed pro. Follow product labels where they differ.

Difficulty 3 of 5 · 1 weekend · careful

Photo of your room, the look you pick, then this guide with the materials counted for your room.

Step by step

1. Step 1 of 11

   Read the sink's sheet and decide who does what

   

   Find the new sink's spec sheet and installation sheet: how it mounts (drop-in, undermount, or apron-front), the cutout size, and the smallest base cabinet it fits. A drop-in sink that fits the old opening is yours from start to finish. An undermount or apron-front sink goes in with a new countertop: the fabricator or the countertop installer mounts it and cuts the opening to the sink, and an apron-front sink also needs an apron-front sink base. Then your part is the drain, from step 8 on.

2. Step 2 of 11

   Measure the opening and the cabinet under it

   

   Measure the old sink's opening, the inside width of the sink base, and where the drain stub and the valves sit. Compare them with the new sink's sheet. A drop-in rim must cover the old opening on every side with room for its clips; a sink that needs a bigger opening in stone is the stop-gate.

3. Step 3 of 11

   Water off at the sink and prove it

   

   Empty the sink base. Close both shutoff valves under the sink and open the faucet: the flow should stop completely. If a valve will not close all the way, weeps at the stem, or will not turn, stop here. Unplug the disposal; if it has no plug and is wired into a box, an electrician disconnects it.

   Safe to start?

   • Both shutoff valves close fully — no drip at the faucet, no weep at the stem
   • The new sink fits the opening you have, or the countertop installer sets it in a new top
   • The disposal is unplugged, or an electrician disconnects one that is wired in — or there is no disposal
   • No gas line will be moved or touched
   • Bucket, towels, and a headlamp under the sink

4. Step 4 of 11

   Unhook the supplies, the drain, and the dishwasher hose

   

   Photograph everything under the sink first. Bucket under the trap. Loosen the supply lines at the valves, then the trap's slip nuts, and let the water drain out. Loosen the clamp and pull the dishwasher drain hose off the disposal or the drain fitting; note how it runs up to the air gap or the high loop so it goes back the same way.

5. Step 5 of 11

   Take the disposal off first

   

   Support the disposal from below, then turn its mounting ring the way its manual says until it drops free. Set it aside: it goes back on the new sink unless you are replacing it.

6. Step 6 of 11

   Free the old sink and lift it out

   

   Drop-in sink: loosen the clips from below, cut the caulk around the rim with a utility knife, and lift the sink out with a helper. If the faucet sits on the sink and will be reused, take it off now with the basin wrench and keep its parts. An undermount sink under a top that stays, or a sink that will not come free without prying against the countertop: stop and read the stop-gate.

7. Step 7 of 11

   Clean the deck and look at the cabinet floor

   

   Scrape the old caulk and putty off the counter around the opening with the plastic putty knife and clean it with rubbing alcohol. Look at the cabinet floor and the wall behind it for stains, soft wood, or mold. Anything soft or dark is fixed before the new sink goes in.

8. Step 8 of 11

   Fit the strainer and the disposal flange to the sink

   

   A drop-in sink: do this with the sink upside down on a padded surface. Basket strainer: putty or the supplied gasket under the flange, as its instructions say; snug the locknut from below. Disposal bowl: the disposal's own sink flange and mounting ring, as its manual says. An undermount or apron-front sink set by the countertop installer: fit these once it is mounted and its adhesive has cured for the time on its label.

9. Step 9 of 11

   Set the sink

   

   Drop-in: run the sealant the sink maker names around the opening, lower the sink straight down with a helper, center it, and tighten the clips from below a little at a time, working around the sink, until the rim sits tight and even. Wipe off the squeeze-out. Undermount or apron-front set by the installer: check their work instead — the sink is level, the countertop edge meets it evenly all around, and it sits on the support the sink maker calls for.

10. Step 10 of 11

    Hang the disposal and connect the drain

    

    Lift the disposal onto its mounting ring and turn it until it locks. A new disposal: knock out its dishwasher plug first if a dishwasher drains into it. Dry-fit the tailpiece, the trap, and the trap arm so the trap hangs level and the arm slopes down toward the wall; cut a tailpiece with the hacksaw rather than force a bend. Slip nuts go hand-tight plus a small turn. Clamp the dishwasher hose back on, running up to the air gap or a high loop as your local code and the dishwasher's manual say.

11. Step 11 of 11

    Test the drain with a bucket

    

    The faucet is not connected yet, so plug the sink, pour in a few buckets of water, then pull the plug and watch every joint under the sink while the water runs out. Plug the disposal back in and run it with water. Dry everything and lay paper towels under the joints. The faucet and its supply lines go on in the plumbing trim-out; look at these towels again after its leak test.

    Quality check

    • The sink is tight to the counter, sealed all around, and does not move when pressed
    • No drip at the strainer, the disposal, the trap, or the dishwasher hose after the bucket test
    • If a dishwasher drains here: its hose runs up to the air gap or a high loop, clamped at both ends
    • If there is a disposal: it runs, and an electrician reconnected it if it is wired in
    • The cabinet floor under the sink is dry and sound

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