How to Install a Farmhouse Sink in Existing Cabinets

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Do you have an existing cabinet that wasn’t originally meant to have a farmhouse sink? Do you now wish to install a farmhouse sink since you are remodeling your kitchen?

When you have a base cabinet already, you need to figure out what it can accommodate before you buy a farmhouse sink at your local hardware store.

Estimating the Dimensions of the Farmhouse Sink You Need

In most cases, you will find certain dimensions of farmhouse sinks that can be installed on existing cabinets.

A ‘minimum base cabinet size’ is recommended.

Typically, this ‘minimum base cabinet size’ is 3-4 inches larger than the length of the farmhouse sink you intend to install. But, there are some exceptions. 

A skilled master plumber or someone with proven experience in kitchen remodeling projects can help install a relatively larger farmhouse sink.

When looking for a new farmhouse sink, you should mainly focus on:

  • Finding out the ideal dimensions of the sink
  • How the base cabinet can be modified to best accommodate the new farmhouse sink

If you consider the maximum side-to-side length of a farmhouse sink, it has to be at least 0.25 inches smaller than the inner-width of your base cabinet. There is no way you can accommodate a larger sink without, of course, ripping apart the adjoining cabinets.

The maximum height of the farmhouse sink that you can install in existing cabinets is equal to the distance between the top of the cabinet doors and the top of the base cabinet.

You will have to cut out the cabinet face to install a new farmhouse sink. Don’t need to worry about the maximum height of the sink even when you plan to customize cabinet doors as well.

But, what about the front-to-back width of the farmhouse sink?

Well, most farmhouse sinks are approximately 18 to 20 inches wide. They are typically designed to comfortably accommodate faucets. So, unless you have some specific requirements, the farmhouse sink’s front-to-back width is hardly a concern.

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Installing Farmhouse Sink in Existing Cabinets

Step 1: Cut the Countertop

Do not cut your countertops ‘before’ you get your farmhouse sink, especially if the sink material happens to be copper or porcelain. Such sinks are generally hand-made. So, you need to keep room for at least 2% error in dimensions in each direction.

Next, you need to cut the counters. The edges of your sink can be visible or entirely covered, depending upon how you cut the counters.

Be sure to cover the target area on the countertop with masking tape for a clean cut. Masking tape helps prevent chipping.

If you want the edges of the sink to be visible, the countertop has to slightly overlap (about 0.25 inches) the sink walls. This will leave ample room for sealing and also help avoid gaps that can promote mold growth in the future.

You also need to factor in the sink wall thickness as well as the front apron’s roundness.

For a coherent look, the round corners should fit a little ahead of the countertop.

Step 2: Cut the Top Part of the Cabinet

Based on the measurements of the base cabinet and the new farmhouse sink, you need to carefully cut the cabinet face.

Be sure to draw an outline of the measurements onto the cabinet face to avoid any mistakes. Use a jigsaw to cut precisely along the outline.

Some rough edges will likely remain. You can apply a fresh coat of paint to give the entire assembly a new look.

Step 3: Build Supports

The new farmhouse sink should stay where it’s meant to be, even when it’s filled with water. So, you need to support the sink on top of the base cabinet.

In case the sink weighs more than 100 pounds, it’s a good idea to opt for a 2×4 support system. This way, your sink can comfortably handle more weight.

If the sink weighs significantly less than 100 pounds, consider using 0.5 inches thick plywood to support it. In case the farmhouse sink is heavier, use thicker plywood to build your supports.

Start by marking the inner walls of your base cabinet, where your new farmhouse sink will sit. When you are marking the marks with a pencil, be sure to check whether the sink is exactly flush with the top of the base cabinet.

Next, install your “2×4 supports” as discussed above. Use both industrial-grade adhesive and screws to firmly attach your supports to the cabinet walls.

Keep in mind that even when you install “2×4 supports,” you still need a layer of thick plywood on top of them for additional stability. You will need to cut holes in the plywood shelf to accommodate plumbing connections.

Step 4: Install Plumbing Fixtures

How to Install a Farmhouse Sink in Existing Cabinets

Next, you need to install the cabinet fronts as well as the plumbing fixtures.

Read more: How Long Does Plumbers Putty Take To Dry?

Make sure to caulk all edges of the new farmhouse sink, wherever they meet the countertop. This will help prevent any moisture buildup.

Installing a new farmhouse sink isn’t exactly a straightforward task, even if you buy a retrofit farmhouse sink. If you do not have any prior experience, consider hiring an experienced professional instead. You don’t want to end up with a serious mess in your kitchen by trying to save a little money!

Read more: What is the Best Caulk For Kitchen Sink?

Differences in a Farmhouse Ink Compared to Apron Sinks

The first mistake homeowners make is not accounting for the weight, especially when farmhouse sinks are filled. Farmhouse sinks such as fireclay and cast-iron can easily be 200 pounds or more. 

So the key difference here is reinforcing the sides when installing. We recommend attaching each side with construction adhesive and flathead wood screws. Then reinforce the sides, mount a crosspiece, and cut out the cabinet to match the sink’s apron. 

Have a plumber install the sink after your new cabinets have been installed if you’re remodeling your whole kitchen. In our experience, farmhouse sinks can take upwards of 3 hours more to install if you have to cut the cabinet top drawer to get it in. 

A plumber can charge anywhere from $350-$950 to install a farmhouse sink depending on your area, the size, the plumbing connection involved, and how much work is involved in making the sink fit properly. 

Final Words 

We know installing a new farmhouse sink in existing cabinets isn’t exactly straightforward. 

However, if you have some DIY experience and know how to use tools such as a jigsaw cutter, you can try completing this project on your own and save some money! 

Just make sure the measurements are correct. You don’t want to buy a farmhouse sink that wouldn’t fit properly on top of the cabinet doors. 

How to Install a Farmhouse Sink in Existing Cabinets