How to Install a Farmhouse Sink in an Existing Cabinet

As an Amazon associate We earn from qualifying purchases.

A farmhouse sink, also known as an apron sink, is wider and deeper than ordinary kitchen sinks. With its capacity, it’s very helpful to large families and especially those whose kitchens don’t include a dishwasher.

They also make an impactful statement on any kitchen.

But you have just installed new cabinets not too long ago. Does this rule out a farmhouse sink?

Not really. You can install a farmhouse sink in an existing cabinet. In this guide, we’ll help you to figure out how to install the sink in the existing cabinetry with ease.

With the cabinet in place already, you need to figure out the sink size it can accommodate before purchasing one.

Estimating the Dimensions of the Farmhouse Sink

How to Install a Farmhouse Sink in an Existing Cabinet

When looking for a farmhouse sink to install in your existing cabinet, you need to find out the sink’s dimensions. You also need to figure out how the existing base cabinet can be modified to accommodate the new sink.

The sink’s maximum side-to-side length has to be at least 0.25″ smaller than your base cabinet’s inner width. You can’t accommodate a larger sink without ripping apart the adjacent cabinets.

The maximum height of the sink to install in existing cabinets equals the distance between the top of the base cabinet and the top of the cabinet doors.

The front-back width of a farmhouse sink shouldn’t be of great concern. This is because most farmhouse sinks are about 18 -20 inches wide. They are designed to accommodate faucets comfortably.

Installing a Farmhouse Sink in An Existing Cabinet

Step 1: Get the Right Tools

For this job, you’ll need;

  • Measuring tape
  • A pencil
  • A jigsaw/oscillating saw
  • Construction adhesive
  • A screw gun
  • 2 x 4 plywood planks
  • Screws
  • An electric drill
  • Silicone sealant
  • Safety goggles

Step 2: Remove the Countertop

If your countertop is screwed on, get the screw gun, remove the screws and lift it out. If it’s glued down, use an oscillating saw to pry it out.

Depending on how you cut the counters, the edges of your farmhouse sink can be visible or not. For a clean cut, use masking tape. It helps prevent chipping.

If you want the edges of your sink to be visible, the countertop has to overlap the sink walls by at least 0.25 inches. It will leave enough room for sealing and help to avoid nasty gaps that can promote mold growth.

When cutting the countertop, you need to factor in your sink wall thickness and the front apron’s roundness. Cut it in a way to ensure that round corners fit a little ahead of the countertop.

Step 3: Cut the Cabinet’s Top Part

Using your measuring tape, measure and outline the cabinet face to avoid mistakes. Get your jigsaw and cut along the outline.

If the sink comes with a template, just use it to make the cuts. Trace the template precisely and use the jigsaw to cut the outline.

If you don’t want to mess up with the measurements, saw inside the lines and then sand the excess. This will prevent overcutting.

Step 4: Build Supports

For the farmhouse sink to stay in place even when filled with water, you need to build supports for it. If it weighs more than 100 pounds, opt for a strong support system (2 x 4) to handle more weight.

Mark the inner walls of the base cabinet where your sink will sit. When marking, ensure that the sink is flush with the top of your base cabinet.

Next, install the 2 x 4 planks and use the screws and industrial adhesive for this procedure. Ensure that the supports are firmly attached to the cabinet walls.

After installing the supports, it’s time to get a plywood shelf for additional stability. Measure the cabinet interior and cut your plywood shelf. Cut a hole in the middle of the shelf and ensure that it has the same circumference as the sink’s drain.

The hole will make room for plumbing.

Take the plywood shelf and place it on top of the supports.

Step 5: Test the Fitting

Now that you have the support in place. Place the sink in it and ensure that the drain hole matches with the hole you made on the shelf. Ensure that there’s no gap between the sink and the support frame.

If the sink fits well, connect the plumbing. You can use new accessories and pipes for plumbing if the old ones are worn out.

Secure the connection tightly with a sealant to prevent leaks.

Step 6: Place the Countertop

If you didn’t destroy the old countertop when removing it, you don’t have to get a new one. Just reuse it and secure it tightly in place with a silicone sealant.

If it got damaged, get a new one and ensure that it’s made of a material that can’t get damaged by water.


From the guide, it’s evident that you don’t have to be a professional to install a farmhouse sink in existing cabinetry. With the right tools and mindset, you can do it with ease. Follow the steps listed above and do it on your own.