How to Change a Kitchen Sink

Kitchen sink can vary in size and shape.  Swapping out your kitchen sink for another model can be incredibly easy or very difficult, depending on the dimensions and material of your sink.  If the dimensions of your replacement sink are odd, it could be difficult to find a replacement that fits exactly into your counter space.  If you are replacing your sink with a larger sink, you will need to recut your countertop to the size of your new sink.  The material of which your new sink is constructed can also impact the amount of work involved.  Ceramic is heavier than stainless steel and might require an extra set of hands.  Another factor affecting the ease of installation is the position of your hot and cold taps, which could necessitate the use of specialty tools like a tube spanner to remove nuts obscured by your sink basin.

Before you start

If your sink is older, your feeds are probably copper pipes that connect directly to your kitchen tap.  When installing a new sink, replace those with modern flexible tap fittings to make any future tap replacements easier.  To do this, you might have to cut your existing copper piping, but future you will thank you for doing the work now!

Step 1: Removing your old kitchen sink

Before you remove your old sink, turn off the hot and cold supply to everything and disconnect your waste pipe.  To remove the sink:

• Disconnect the taps from the hot and cold water feed pipes under your sink.  Depending on their location, you may need a tube spanner or other tool to access the nuts.
• If your sink is secured to your countertop with silicone, cut or score the silicone around the edges of your sink with a sharp blade.
• Unscrew the clamps attached to your sink on the underside of your counter.  There are usually about ten clamps.

Step 2: Preparing the area for your new sink

Clean the sides of your countertop and remove any scum or old silicone.  Measure to ensure the hole is large enough for your new sink.  If it isn’t, measure the size hole you will need and cut accordingly.  This process can vary in difficulty, depending on the material of which your countertop is made.

Step 3: Installing your new sink

Mockup your new sink to ensure everything is OK before sealing.  Your new kitchen sink won’t be preconfigured with a hole to accommodate taps because taps come in all shapes and sizes.  You will need to either make the holes yourself or hire an experienced, licensed plumber to do so.  If your new sink is ceramic, we recommend hiring an experienced, licensed plumber to do this because you run a risk of cracking and ruining your new sink.

Next, permanently fix your sink into place.  Because of their weight, ceramic sinks will stay in place with only a bit of silicone to secure them.  Stainless steel sinks require that clamps be used to fit them into your countertop.  These clamps are supplied with the sink and installed on the underside of your countertop.  Before dropping your new sink into the hole, lay a line of clear silicone around the perimeter of the hole you’ve made for your sink in the countertop.  The smaller the line, the less silicone you’ll have sticking out the side of your sink.

Once everything is in place, fit a new kitchen mixer tap into your sink.  Most modern kitchen taps are mixer taps that deliver both hot and cold-water trough a single pipe directly into your sink.  Each tap has a standard half-inch thread on the bottom and comes supplied with a washer that secures from the underside of your sink with a small nut.  Most also come with a foam plate that is placed underneath the tap to allow a tight seal.  To fit your new mixer tap, just slot the tap pipes through the holes in your sink and connect them underneath the sink with a washer and plastic nut.  Use a tool to tighten them as securely as possible, or they will wobble with use.  Replace rubber washers and O-rings wherever possible and use PTFE tape to ensure an absolute watertight seal.  When you’re finished, turn your water back on and test for leaks.  The first time you run your water, you’ll get some air, but then water will run through smoothly.

Changing your kitchen sink can be easy or a lot of work.  If this sounds like too much work for you, call an experienced, licensed plumber.