Installing An Undercounter Kitchen Sink Installing An Undercounter Kitchen Sink

What You'll Need
Undercounter sink
Denatured alcohol
Steel or wire brush
Rags for cleaning
Permanent Magic Marker
Pure silicone caulk
Small paint brush
Epoxy contact glue
Mounting hardware
Pipe wrench
Drain assembly

When considering new sink options, a kitchen undercounter sink is a convenient option. Undercounter sinks are stylish and easy to clean and maintain. They come in a wide assortment of styles, colors and materials, and you will almost certainly be able to find one that suits you and matches the décor of your kitchen.

Step 1– Inspect the Sink and Faucet Opening

Your countertop should already be installed before attempting to install an undercounter sink; you should have had the counter installer already cut, grind and buff out the opening for your sink and faucets. In addition, the installers should have pre-drilled the holes for your mounting hardware. Your sink will have come with a template to show the installer exactly where to drill the holes. If this has not been completed, have the installer prepare the opening before continuing.

Step 2– Preparing the Opening

Using the steel or wire brush, clean the sink opening's inside edges and underside of the countertop, and then thoroughly wipe with denatured alcohol and a damp rag. There will be tiny pieces of debris left over from the cutting and grinding of the opening. This debris will not allow the sink to adhere properly to the countertop if it's not cleaned properly. Use the wire brush to loosen the fragments and debris, and then use the alcohol to clean it and remove.

Step 3– Prepare the Countertop

In order to properly attach the sink to the countertop, you will need to turn the countertop upside down. Countertops are very heavy; therefore, you will probably need the assistance of two or three people to turn the countertop upside down. You should place old towels or other materials on the floor so that the countertop is not scratched or damaged.

Step 4– Measuring and Attaching the Sink


Place the sink directly over the hole in the countertop, and then using your magic marker, make an outline of the sink so that you will know exactly where it should be placed. Then, mix the epoxy glue according to the manufacturer's instructions. While you are placing your sink, the epoxy glue will need a few minutes to set.

Using the silicone caulk, caulk around the edges of the sink, and then firmly press it down onto the counter. Make sure to follow the outline that you created with your magic marker. Next, brush the epoxy glue onto the posts of the mounting bolts, which are next to the lip, or edge, of the sink. Securely tighten the mounting screws. Applying the epoxy glue will ensure that the mounting hardware does not become loose during normal usage. Allow the epoxy glue to dry overnight; simply leave the countertop on the floor and in its present position.

Step 5– Replacing the Countertop


Use your silicone caulk and caulk a bead of silicone along the top edges of the cabinets, then flip the countertop over and place in on top of the cabinets. Again, make sure to get someone to help you.

Step 6– Install the Sink Drain


Using the plumber's putty, form a thin tube-like roll and place it around the bottom of the drain assembly. Then, push the drain assembly firmly into the hole - so that any excess putty comes out around the edges. Underneath the sink, securely tighten the lock nut to the drain assembly. For this, you will use a standard pipe wrench. Make sure not to tighten the lock nut too much, or this may cause the drain to leak. Finally, connect the drain to P or S trap compression fitting. Make sure to hand tighten these connections securely, but don’t use a pipe wrench.

You have now installed your undercounter sink, and it is ready for use. Call in the family, and let them admire your handy work.

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