DIY Network

How to Install a Sink and Seal Seams in a New Slate Countertop

DIY remodeling expert Paul Ryan shows the proper way to install a sink and natural slate countertop.

More in Kitchen

kitchen update creates a traditional space
  • Time

    2 hours

  • Price Range

    $50 - $100

  • Difficulty



Step 1: Install the Sink

In this kitchen remodeling project a stainless-steel double sink is undermounted to a new slate countertop. The slate countertop was cut at the countertop fabricator to receive this particular sink. Before either is permanently set in place, however, it's important to "dry fit" the sink and the countertop to ensure perfect fitting.

The sink has to be mounted before the countertop can be secured to the cabinet tops. You can use the countertop as a template to mark where the cabinets need to be cut to make room for the sink.

Rest the sink area countertop on top of the sink cabinets, and look for any cabinet pieces that may block the new sink. Remove the countertop and cut out any excess cabinet lumber with a reciprocating saw.

Remove the sink and flip the countertop face down onto the sawhorses.

With a clean cloth, wipe the countertop with acetone where the sink will touch so the silicone, which, in addition to the clips, helps to secure the sink to the countertop, sticks properly to the countertop surface.

Slide the sink into place and trace the sink's outline with a pencil.

Remove the sink and run a bead of silicone inside the mark, making sure silicone covers appropriately without spilling over the sides.

Set the sink in place.

If the countertop was properly pre-drilled and pre-anchored at the fabricator's, put the clips into place and screw them into place. If the countertop was not pre-drilled, check with the fabricator for his preferred method of anchoring the sink into the countertop.

When everything is secured, carefully lift the countertop with the undermounted sink and place it in its new home.

Once the sink is in, take out the kitchen cabinet drawers and silicone the new slate countertop in place. Do not secure those countertop sections that meet at seams until those seams have been sealed (see Step 2).

Step 2: Seal the Seam on the Countertop

While installing a new slate kitchen countertop, chances are good that two pieces of slate will meet at a seam. It's best to seal the seam so food particles or other cooking excesses can’t reside in the seam.

To start, place blue painter's tape across the length of the seam.

Score the tape on the seam with a utility knife.

Use a carpenter square to make two to three reference marks across the tape so the marks can be lined up perfectly after you separate them.

Pull the two touching countertops apart by about an inch.

With a wood shim, butter the butting edges of the seam with epoxy.

Push the countertop pieces back in place, making sure you match the reference marks on the tape.

Drag a razor blade over the tape to work epoxy into the seams and make sure there are no air pockets.

Once the epoxy is dry, peel off the tape and look for any epoxy that might have seaped out. If so, clean the area with acetone.

score tape on seam with utility knife