A true corner kitchen sink is not a rectangle, so installation is not standard and could prove challenging to the inexperienced. This DIY installation overview will help if you decide to tackle the work.
If you hire a kitchen sink installer or general contractor, these tips will help you discuss the process with them.
Whether you have a drop-in sink with a lip that rests on the countertop (also called topmount) or an undermount sink, you’ll need to cut a hole in the countertop. That’s the toughest part. If you have an undermount sink, the second challenge will be to provide support rails for the sink to rest upon, if they are required or you add them by choice.
To install a corner sink, you’ll need:
- Tape measure
- Marking pencil
- Wood screws
- Painter’s tape
- Silicone sink caulk
- Safety glasses or goggles
Cutting the Sink Hole in the Countertop
The sink you select might come with a template. If not, you’ll have to create one on craft paper. To do so, lay a full sheet of paper on the countertop, and rest the sink on the paper face-down. Trace around the sink, and cut out the template.
- Position the template on the countertop or countertop substrate (for a tile countertop, e.g.) exactly where you want the sink to be positioned
- To reduce splintering of the countertop, use painter’s tape to tape the template to the counter, and overlap the template by ½” or more, and retrace the edge of the paper onto the tape, if necessary
- Use a large drill bit or a hole saw to cut a starter hole on the inside of the template – in countertop material that will be removed
- Use a jigsaw to cut the hole for the sink using the template as a guide
- Note: Once more than half the distance around the template has been cut, the material being removed should be supported from beneath to prevent it from falling and splintering the remaining countertop material
Installing a Drop-in Sink
Once the sink hole has been cut, the rest is quite easy.
- Run a bead of silicone caulk around the underside of the sink lip
- Insert the sink through the hole, and press it into place
- Wipe away any caulk that squeezes out from under the lip
- Attach any included clamps or brackets in the underside of the sink bowl to the countertop from below
- Install the disposer and/or sink drain or drains
Installing an Undermount Corner Sink
The basics for undermount sink are easy too, once the hole is cut.
- Turn the countertop upside down
- Run a bead of silicone caulk around the entire hole, about 1/8” from the edge
- Place the sink over the hole, and push it down slightly
- Use the clamps included with the sink to attach it to the bottom of the countertop or substrate (for a tile countertop, e.g.)
- Note: Predrill the screw holes in the countertop, if recommended by the countertop manufacturer, being sure to control depth so that they screws don’t go through the countertop
- The sink is now attached and ready for the countertop or substrate to be installed
Supporting an Undermount Sink
While this isn’t necessary for all sinks, you might want to consider it.
- Once the sink and countertop are installed, measure the distance from the inside front to the back of the sink cabinet
- Cut 1”x1” or 1”x2” pieces of wood to fit
- Place them where they will provide support to the rim of the sink
- Secure them to the front and back of the cabinet using wood screws
- Tip: Some installers attach support brackets to the underside of the counter, but for heavy sinks, it is better to attach them to the base cabinet because this takes weight off of the countertop
The Cost to Install a Corner Kitchen Sink
If you receive estimates for just the installation of a sink, expect this price range:
- Kitchen corner sink installation: $100-$400
Where your estimate is in this range depends on what needs to be done during installation. If support braces are installed, the price might be slightly higher. Installing multiple accessories such as a sprayer and soap dispenser will increase the cost. So will installing a garbage disposer, water filter or on-demand water heater.
Corner Sink Installation FAQ
This brief corner sink installation Q&A answers common questions from readers.
What is the reveal on an undermount sink?
It refers to whether or not the top edge of the sink shows. You’ve got three options:
Negative reveal: This means that the countertop overlaps the sink edge slightly, and the sink hole is cut slightly smaller than necessary to achieve the effect
Flush (or Zero) reveal: This means that the edge of the countertop and the sink edge are flush
Positive reveal: This means that the sink edge will show from underneath, so the sink hole must be cut slightly larger than necessary
What type of reveal do you recommend?
Most installers recommend a flush or negative reveal. Having the sink top edge show (positive reveal) creates a place for food debris to collect and perhaps stain the sink. A slightly negative reveal, with the countertop overhanging the sink by about 1/8”, allows you to sweep crumbs right into the sink bottom without them sticking to the sink side. Just keep in mind that the underside of the overhang should be cleaned regularly. You can’t see it, but that doesn’t mean that it isn’t getting dirty.
Do stainless steel sinks need extra support with undermount installation?
No, but it never hurts. Ask your installer for suggestions, or add a brace on either side if you do the work yourself. Just keep in mind that you must use short screws, so they don’t penetrate through the cabinet face.
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