Installing a drop-in sink

January 16, 2013

Installing a drop-in sink is a project you can easily do yourself. This guide includes installation information for cutting a laminate countertop. However, you may prefer to have this done for you by a professional, especially if your countertop is composed of stone or other hard materials that may require special tools and cutting expertise.  If this is the case, or if your countertop already has a hole for the sink, you can begin your project at step eight. As you work on your project, be sure to follow any manufacturer’s instructions that come with your sink.

Tools and materials:

Tape measure Scissors Power drill
Bits (including 3/4" spade bit) Plastic putty knife Screwdriver
Utility knife Caulk gun Jig saw
Drop-in sink Masking tape Carpenter's pencil
Silicone caulk Rag

Before You Start


  • Install the faucets and most of the trap on the sink before setting it into the countertop.
  • If the drain doesn't line up properly, you can combine 95- and 45-degree elbows with short pieces of straight pipe to make connections.  
  • Plumber's putty can discolor marble, so if your sink is make of cultured marble use silicone caulk in step eight.


  • If you plan on installing a cast-iron sink, it will be heavy, so get help when placing it in the opening.
  • If you are cutting the countertop opening yourself, be sure to wear hearing and eye protection and follow other safety precautions appropriate for the tools you use.


  • PVC traps can save you time when you're connecting the drain because they are more flexible and easier to work with than chrome pipes.
  • Consider using a high-speed cutting tool, as an alternative to a saber saw, for quickly cutting out a countertop.
  • If you are removing an existing sink, consider recycling or donating it to a local charity rather than just throwing it in the garbage.

Step 1. Create a template (if your sink comes with a template, skip this step and begin your project at step 2).

1.  Lay the sink upside down on a piece of cardboard and draw a line around it. 
2.  Remove the sink and draw a second line ¾” inside the first line. 
3.  Cut along the inside line with scissors. 


Step 2. Mark the center of the countertop.

1.  Measure the length and width of the countertop from underneath and make a mark at the exact center. 

2.  From underneath, drill a hole at the exact center of the countertop large enough to fit a nail through. 

Step 3. Position the template.

1.  Determine the exact center of the template and place a mark at the center. 

2.  Push a nail through the center of the template. 

3.  Align the hole in the template over the hole in the countertop and push the nail through the aligned holes to anchor the template. 

Step 4. Trace the template outline on the countertop.

1.  Make sure the edges of the template are square. 

2.  Trace the outline of the template on the countertop. 

3.  Remove the template and apply masking tape centered over the line. 

4.  Center the template again and draw the outline of the template on the tape. 

Step 5. Drill starter hole.

Use a power drill and ¾” spade bit to make a starter hole for the saber saw.

Step 6. Install braces under the countertop.

Support the section of the countertop you’re cutting with scrap wood or 2X4s placed beneath the countertop to keep the material from binding while being cut.

Step 7. Cut along the line on the countertop.

1.  Cut along the line using a down-cutting 5/16” wide laminate or similar saber saw blade designed to cut countertops without chipping. Ease the blade through turns with a series of short cuts inside the curves. 

2.  When the cut is complete, remove the cut portion from the countertop. 

Step 8. Apply caulk around opening.

1.  Test fit the sink in the opening. 

2.  Draw a line around the sink rim lightly on the countertop. 

3.  Remove the sink and apply a steady, continuous bead of caulk around the opening between the line and the edge of the opening. 

Step 9. Place sink in opening.

1.  Holding the sink by the sink holes, place and center the sink in the opening. 
2.  Press the sink firmly into the silicone caulking. 

3.  Make sure the sink is level and squared.

Step 10. Install fixtures and clean up excess silicone.

1.  Connect the faucet and drains and test for leaks. 

2.  Use a rag and plastic putty knife to clean up any excess caulk around the sink edge. 

Need expert assistance? Visit your local Home Depot store to ask their associates about products or how-to instructions. The Home Depot expert associates are also available to answer your questions online. Visit them here.