Double Farmhouse Sink: 50/50 vs 60/40 and Cabinet Fit

Most people pick a double farmhouse sink for the look, then discover the real decisions are hidden under the apron: which bowl split suits the way they cook, whether the base cabinet is wide and strong enough, and how two drains get tied into one trap. Get those three things right and a double basin apron sink is one of the most useful fixtures in a kitchen. Get them wrong and you end up with a bowl too narrow for a sheet pan and a cabinet that sags under a fireclay sink full of water.

The short answer: choose a 60/40 split if you wash large pots and pans by hand, a 50/50 split if you want equal wash and rinse zones, and plan on a 36 inch base cabinet as the practical minimum. A 33 inch double bowl farmhouse sink exists, but the bowls get cramped fast. Both drains normally connect through a continuous waste kit into a single P-trap, so the plumbing is less complicated than it looks.

Double Farmhouse Sink Basics: How the Bowl Splits Differ

Every double farm sink divides its interior with a center wall, and the position of that wall changes how the sink works day to day. Three layouts dominate the market.

50/50 Equal Bowls

Two identical basins give you a clean wash and rinse routine, or a prep side and a dirty dish side. On a 36 inch sink, each bowl lands around 15 to 16 inches wide, which fits a dinner plate easily but will not let a large roasting pan or baking sheet lie flat. Households that run the dishwasher daily and hand wash only a few items tend to like this layout.

60/40 Offset Bowls

The larger bowl, usually 18 to 20 inches wide on a 36 inch unit, handles stockpots and cookie sheets while the smaller bowl holds the disposal or serves as a rinse and prep station. This is the most popular split for a reason: it keeps most of the flexibility of a single bowl while still giving you a second basin. Decide which side the big bowl goes on based on where your dishwasher sits and which hand you favor.

Low Divide Designs

Some double basin farmhouse sinks use a center wall that stops a few inches below the rim. You can lay a long pan across both bowls to soak, yet still fill one side on its own. The tradeoff is that water overflows from one bowl to the other if you fill past the divider, so it is less useful for soaking two separate loads at once.

Cabinet Fit: Width, Depth and Support

An apron front sink sits in a notched base cabinet, with the front of the sink replacing the top drawer face. That means the cabinet has to be built or modified for it, and the sizing rules are stricter than for a drop-in sink.

• Width: A standard 36 inch farmhouse sink base holds a sink up to about 33 to 36 inches, depending on the maker’s cutout spec. Many double sinks need a 36 inch cabinet at minimum, and 42 inch or 48 inch sinks require matching larger bases.
• Depth: Most apron sinks run 20 to 22 inches front to back, which fits a standard 24 inch deep base with room for the faucet deck.
• Apron height: Aprons range from roughly 7 to 10 inches tall. The cabinet face must be cut to match, and the sink rim height has to align with the countertop underside.
• Weight: A 36 inch fireclay double sink can weigh 100 to 150 pounds empty. Add a few gallons of water, dishes and a person leaning on the edge and the load climbs quickly.

Always check the specification sheet from the sink manufacturer before ordering or cutting a cabinet. Cutout dimensions vary even between sinks with the same nominal width, and a quarter inch mistake on the apron opening is hard to hide.

Building a Proper Support Frame

Because a heavy apron sink rests on the cabinet rather than hanging from the counter, the support structure matters. Treat this as structural work, not trim carpentry.

1. Measure the sink’s actual height, width and apron depth with the sink on the floor. Do not rely only on published numbers.
2. Install 2×4 ledger rails along both cabinet side walls, screwed into the cabinet sides and, where possible, into a back cleat anchored to wall studs.
3. Add a cross support of 3/4 inch plywood or a 2×4 frame across the ledgers so the sink bottom has full contact. Shim until the sink rim sits flush with, or just below, the counter underside.
4. Dry fit the sink and check level front to back and side to side. Most apron sinks are designed to sit dead level, and their bowls are sloped internally toward the drains.
5. Set the sink on a bead of silicone at the rails, then have the countertop templated with the sink in place. Stone fabricators need the actual sink on site to cut accurately.

If your cabinet is a frameless or particleboard box, reinforce the sides with plywood before adding ledgers. Particleboard screws pull out under sustained load, and a sink that settles even 1/8 inch can crack a stone countertop seam.

Double Drain Plumbing: One Trap for Two Bowls

Two drains do not mean two traps. The typical setup uses a continuous waste kit: a tailpiece drops from each bowl, a horizontal branch (or an end outlet tee) joins them, and a single P-trap connects to the wall drain. With a garbage disposal, one bowl feeds the disposal and the disposal outlet ties into the tee on the other side.

A few details trip people up with a double bowl farmhouse sink:

• Apron sinks often sit lower in the cabinet than drop-in sinks, which can push the trap too close to or below the wall drain stub. The trap arm needs a slight downward slope toward the wall, generally about 1/4 inch per foot.
• Offset drains, placed toward the back of each bowl, free up cabinet space and help keep the horizontal branch above the trap. Check drain location before you buy.
• A dishwasher hose needs an air gap or a high loop and connects to the disposal inlet or a dishwasher tailpiece, never below the trap.
• Strainers on fireclay and cast iron sinks usually need a basket strainer rated for thick sink walls. Standard strainers designed for thin stainless steel can come up short.

For a step-by-step look at the pipes, fittings and venting, a dedicated double kitchen sink plumbing guide covers it in more depth. The main point here is to plan the drain height before the sink goes in, because moving a wall drain after the countertop is installed is a much bigger job.

Materials and What They Mean for a Double Sink

The material affects weight, noise, durability and how the center divider holds up.

Stainless steel double sinks are the easiest retrofit because they are light and often come in 16 or 18 gauge with sound deadening pads. Fireclay and cast iron deliver the traditional farmhouse feel but demand a reinforced support frame under the sink.

When a Single Bowl Is the Better Choice

A double farmhouse sink is not always the right call. Consider a single bowl if:

• Your base cabinet is 33 inches or narrower. Splitting that width leaves two bowls that are both too small to be comfortable.
• You regularly wash sheet pans, large cutting boards, or canning pots. Even the big side of a 60/40 sink may not fit a half sheet pan flat.
• You rely mostly on the dishwasher. Many households find that a single large bowl with a roll-up drying rack or a bottom grid does everything a second basin would.
• You want the easiest cleaning. A single bowl has no divider corners to scrub.

On the other hand, a double bowl farmhouse sink wins in busy kitchens where two people work at once, where you want to keep raw meat prep separate from rinsing produce, or where one side stays full of soaking pans while the other remains usable.

Cost Ranges

Prices swing widely by material and brand tier, but general ranges help with budgeting:

• Stainless steel double apron sinks: roughly $300 to $900
• Composite granite: roughly $400 to $1,000
• Fireclay double basin: roughly $700 to $2,000
• Cast iron: roughly $900 to $2,500
• New or modified sink base cabinet: $200 to $800, more for custom cabinetry
• Plumbing hookup by a plumber: often a few hundred dollars, more if the drain must be lowered or moved
• Countertop cutout and fabrication changes: varies with stone type and whether the counter is new or existing

Retrofitting an apron sink into an existing counter is the expensive scenario. Existing stone usually has to be recut or replaced, and the old cabinet face must be modified cleanly.

Troubleshooting Common Problems

Water pools in one bowl: Check that the sink is level. If the sink tilts, the internal slope no longer points to the drain. Reshim the support frame.

Slow drain on the non-disposal side: The horizontal branch may be too flat or the disposal outlet may sit too low. A properly pitched branch and a high enough tee usually solve it.

Gap between sink and counter: The frame has settled or the sink was set too low. Add shims under the sink, then reseal with kitchen and bath silicone.

Leak at the strainer: Fireclay rims are thick, so use a strainer designed for them and seal with plumber’s putty or silicone per the strainer maker’s instructions.

When to Call a Licensed Professional

Swapping a stainless sink of the same size is a reasonable DIY job. Converting a standard base to an apron sink cabinet, setting a 150 pound cast iron sink, or relocating a drain is different. A licensed plumber should handle any drain relocation, vent changes, or new supply lines, and many areas require a permit for plumbing changes beyond a like-for-like swap. Always shut off the water supply valves and relieve pressure before disconnecting lines.

If a disposal is involved, turn off its breaker and confirm power is off with a non-contact voltage tester before touching the wiring. Any new outlet or circuit under the sink should be installed by a licensed electrician and GFCI protected. For heavy sinks, work with a helper and lift with your legs; dropping a fireclay sink onto a cabinet edge can crack both.