How to Install a Composite Kitchen Sink

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Things You'll Need

  • Jigsaw (optional)

  • Sawhorse

  • Plumber’s putty

  • Pliers

  • Caulking gun and silicone caulk

  • Braided steel hoses

  • 24-inch bar clamps

  • 2-by-4 lumber, 6 feet long

  • Epoxy

Composite sinks are attractive, durable and lasting.
Image Credit: Jupiterimages/Goodshoot/Getty Images

Made from two or more materials such as resin, acrylic, quartz and pigments, composite sinks are attractive, heat-resistant, easy-to-clean and durable. The solid-surface, nonporous sinks tolerate moderate wear and tear, and provide years of service. Installing a overmount or undermount composite granite kitchen sink is a simple process that requires a few basic tools. Before you begin, turn off the water supply to the sink. Remove your old sink and clean the sink cutout before installing your new composite kitchen sink.

Installing Overmount Sink

Step 1

Dry-fit the composite kitchen sink in the current sink hole to ensure it fits snugly. If required, widen the cutout in the counter using a jigsaw.

Step 2

Set the composite sink face down on a sawhorse. Insert the faucet's tail piece and supply tube through the gasket and up through the sink holes. Also screw nuts and washers to the lower surface of the sink's deck. Ensure that the faucet can swing a complete arc across the composite sink surface before you tighten the nuts.

Step 3

Loop a thick roll of plumber's putty under the strainer's lip and insert it into the drain hole while the sink is still upside down. Slide the gasket and washer on the strainer, flush against the sink's underside.

Step 4

Slide the lockout on the strainer, hold it in place and tighten it with pliers. Slip the gasket over the tailpiece and secure it to the strainer with the nut. Tighten this nut to secure the assembly.

Step 5

Run a bead of caulk around the sink's lip while it is still face down. Turn it right side up and insert it into the sink hole. Join the faucet to the shutoff valves using braided steel hoses. Also join the trap adapter to the tailpiece using PVC pipes.

Installing Undermount Sink

Step 1

Insert the lower end of the bar clamps into the drain holes along the base of the composite sink. Spread a length of 2-by-4 lumber over the sink cutout, with its ends resting over the edges of the corresponding countertop.

Step 2

Lift the sink into place, ensuring it is even. Tighten the clamps to the 2-by-4 lumber to hold the sink while you install it.

Step 3

Apply epoxy to the metal clips provided with the assembly and attach these to the lower surface of the countertop so they hold the sink in place. Read manufacturer's directions for the placement and number of clips you need to use, so your sink is stable.

Step 4

Install the sink faucet through the pilot holes in the countertop. Remove the clamps and lumber. Wind plumber's putty around the drain hole and attach the strainer to it. Tighten the lockout nuts underneath the sink.

Step 5

Install the drain assembly from the sink hole to the base of the cabinet. Insert it into the drain and tighten the nut to hold it in place. Install the drainpipe and trap adapter to the bottom of the sink.

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