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Kitchen Sink Replacement: Drop-In, Undermount & Farmhouse

Updated 2026-10-31 · Sources verified 2026-07-20

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Three mounts, and the countertop decides which you can have. Permit in Orange County: usually treated as minor no-permit work for a like-for-like swap. FBC 105.2 strictly exempts only repairs that do not replace fixtures and the county publishes no sink-swap exemption: confirm with OC sub-trades (407-836-5564). Moving the drain or supply stubs, or adding a bowl, is permit work. The full rule and its official source are below, with the code requirements and mistakes that trip up Orlando homeowners.

Key facts before you start

Three mounts, and the countertop decides which you can have. A drop-in (self-rimming) sink sits on the counter and hides the cutout edge, so it works on laminate as well as stone; Kohler's cast-iron drop-in guide is blunt that the sink 'is not intended for undercounter installation'. An undermount hangs beneath the slab and Elkay says it 'should only be fastened to a solid surface countertop (i.e. granite / Corian)', with 'the sink cutout and mounting holes ... cut by the countertop fabricator prior to installation'. A farmhouse (apron-front) sink replaces the cabinet's false drawer front with the sink's apron: Elkay ships 'no cutout template' and asks you to give 'the cabinet maker ... the actual sink to be installed'.
Measure the old sink before you shop. For a drop-in replacement, the new rim must cover the old hole: Kohler's cutout table shows a 33 x 22 in sink needs a 31-3/4 x 20-3/4 in opening, so a new 33 x 22 only works if the old cutout is that size or smaller. Count the faucet holes in the old sink or deck, check the base-cabinet width (Kohler's Whitehaven apron sink wants a '33 in minimum base cabinet width'), and compare bowl depth: a deeper new bowl lowers the drain outlet, and the P-trap under it has to drop with it.
Removal: close both supply stops (if they won't shut, close the house valve), disconnect the faucet supplies, the trap's slip nuts with a bucket under them, the disposal (hang its weight, then twist it off its mount) and the dishwasher drain hose. Cut the caulk line around the rim, back off the clips under a drop-in rim, then lift. Kohler: 'Cast iron sinks are very heavy. Get assistance lifting the sink into place', and 'Inspect the drain and supply tubing. Replace if necessary' while the cabinet is open.
Drop-in install (Kohler self-rimming): 'If possible, assemble the faucet and drain assembly to the sink before installing the sink'; cut the opening from the template ('cut the hole in the countertop before installing the countertop' when you can), set the sink 'so the Kohler logo is to the back', 'Apply a thin continuous bead of quality sealant around the sink edges', wipe the excess, 'Allow the sealant to cure for at least 30 minutes before proceeding'. On a composite or china drop-in Kohler specifies '100% clear silicone sealant where the sink will contact the countertop'.
Undermount install (Kohler): build a 2x4 support frame inside the cabinet, 'Allow for adequate clearance for the water supply lines between the support frame and the back of the cabinet', level it so 'the top of the kitchen sink is flush with the top of the cabinet wall or no more than 1/16 to 1/8 in below', shim the sink, 'Apply a bead of 100% silicone sealant around the top of the kitchen sink', set the countertop, then a thin bead where sink meets stone, wiped immediately. The cutout 'should provide a positive reveal to the top of the kitchen sink' so racks and colanders move freely, and 'For new installations, DO NOT install the drain to the kitchen sink before installing the kitchen sink.' Kohler says this install 'must be done by a qualified professional only'.
Undermount clips (Elkay): 'fasten the mounting brackets loosely into the pre-drilled mounting holes in the countertop', 'Lightly tighten the fasteners with a screwdriver until the sink is snug against the countertop', check the alignment to the opening, 'then tighten the fasteners until the sink is tight against the countertop. Do not over tighten. Wipe away any excess caulk with a rag.' Elkay offers two reveals, a 1/2 in countertop setback or a 1/8 in overhang, and wants everyone to agree on which before the slab is cut.
Farmhouse install (Elkay stainless farmhouse; Kohler Whitehaven): 'Remove the false drawer front from the base cabinet', screw a 'mounting wood strip on sides and bottom of front panel' so the apron mounts 'flush to cabinet', with fasteners 'through cabinet to secure to wood strip ... (3) across front and (1) on each side'. 'Support the sink in place from the bottom', silicone the flanges, 'Lower the countertop into place on the cabinets. Press the silicone and flange up onto the countertop.' Kohler's cabinet test for its short-apron Whitehaven: 'The distance from the top edge of the cabinet to the top of the cabinet door must be at least 6-7/8 in to install this sink.'
The strainer (Kohler K-8807): 'Apply a ring of plumbers putty or other sealant to the underside edge of the ... strainer body flange. Insert the ... strainer body in the sink. Assemble a gasket, plate, and nut to the drain body from under the sink. Wrench tighten.' Then the rule people break: 'Do not reposition the drain after the locknut has been tightened.' Slide the nut onto the tailpiece, thread it to the strainer body, 'If necessary, cut the tailpiece to ensure proper fit.' Elkay's drain sheet is the same sequence and ends with 'Wipe away any excess plumber's putty from the sink with a rag.'
The trap under a new sink still has to meet the code (FBC-Plumbing 1002.1): 'The vertical distance from the fixture outlet to the trap weir shall not exceed 24 inches' and the horizontal run to the trap inlet 'shall not exceed 30 inches'. A double bowl may share one trap only if 'one compartment is not more than 6 inches deeper than the other compartment and the waste outlets are not more than 30 inches apart' (Exception 2). 'S' traps are prohibited (1002.3) and the trap seal must be 2 to 4 in (1002.4). A deep farmhouse bowl plus a disposal can push the outlet below a high wall stub; if the stub has to move, that is permit plumbing.
Permit: Orange County's no-permit list covers 'Replacing cabinets or countertops in the same location (without changing the layout)' and says most 'plumbing ... work does require a permit'. A like-for-like sink on the existing drain and supplies is commonly treated as minor work, but FBC 105.2 strictly exempts only repairs that do not replace fixtures and the county publishes no fixture-swap exemption, so confirm with OC sub-trades (407-836-5564). Moving the drain or supply stubs, adding a second bowl where there was one, or new pipe is plumbing-permit work. The disposal and dishwasher hookups have their own guides.

The permit answer

Check with your building department. Strictly read, FBC 105.2 exempts only repairs that do NOT replace fixtures or valves, and Orange County publishes no fixture-swap exemption — commonly treated as minor work, but confirm (OC sub-trades: 407-836-5564).
Source: https://up.codes/viewer/florida/fl-building-code-2023/chapter/1/scope-and-administration

Orange County and the City of Orlando run separate permit offices with separate portals — and your mailing address alone doesn't tell you which one covers your home. Check which permit office covers your address →

Kitchen Sink Replacement: what it looks like

new kitchen faucet over undermount stainless sink

Manufacturer instructions

The manufacturers' own instructions this guide is built from. Follow the manual for your exact model; they open on the manufacturer's site.

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Frequently asked questions

Do I need a permit for a kitchen sink replacement in Orange County, FL?

Check with your building department. Strictly read, FBC 105.2 exempts only repairs that do NOT replace fixtures or valves, and Orange County publishes no fixture-swap exemption — commonly treated as minor work, but confirm (OC sub-trades: 407-836-5564).

Are there specific building-code requirements for a kitchen sink replacement?

The trap under a new sink still has to meet the code (FBC-Plumbing 1002.1): 'The vertical distance from the fixture outlet to the trap weir shall not exceed 24 inches' and the horizontal run to the trap inlet 'shall not exceed 30 inches'.

What tools or parts do I need to get right for a kitchen sink replacement?

Undermount clips (Elkay): 'fasten the mounting brackets loosely into the pre-drilled mounting holes in the countertop', 'Lightly tighten the fasteners with a screwdriver until the sink is snug against the countertop', check the alignment to the opening, 'then tighten the fasteners until the sink is tight against the countertop.

Looking for a different repair?

Sources

https://resources.kohler.com/onlinecatalog/pdf/1053525_2.pdf
https://techcomm.kohler.com/techcomm/pdf/1634499-2.pdf
https://techcomm.kohler.com/techcomm/pdf/1368978-2.pdf
https://techcomm.kohler.com/techcomm/pdf/112446-2.pdf
https://pdf.lowes.com/productdocuments/176a282b-049c-4b65-803e-cda5bb02913c/10606373.pdf
https://images.salsify.com/image/upload/s--FQ-ODGob--/eeea33aa29bc24d5889cb76c4669a4fe34640ffd.pdf
https://up.codes/viewer/florida/fl-plumbing-code-2023/chapter/10/traps-interceptors-and-separators#1002.1
https://engageorange.ocfl.net/fast-track-permitting-services/faqs

This guide is general informational content, not professional or legal advice. Codes and county rules change — confirm permit requirements with your local building department, and use a licensed professional for electrical, gas, structural, or main-line plumbing work.