How to Replace an Undermount Sink

Updating an undermount sink is an easy way to improve the look of your kitchen. Learn how to replace an undermount sink in this Lowe’s video:

Before you buy a new sink, take measurements to ensure it will fit perfectly in the existing hole.

For this project, you will need an undermount sink. clear silicone caulk, caulk gun, tape measure, paint scraper, utility knife, denatured alcohol and a hand clamp. This project is best done with two people.

An undermount sink is attached to the countertop with silicone sealant and metal clips. To remove the old sink, use a razor knife to slice through the silicone, then unscrew all the clips. If your old sink is in good condition, consider donating it to charity instead of throwing it away.

Next, prep the surface for the new sink. Use a razor scraper to remove any remaining old silicone. Clean the countertop and the new sink with denatured alcohol.

Position the sink in the cabinet below the hole and apply a bead of 100% silicon sealant along the edge. Have one person hold up the sink to ensure it’s positioned correctly. Lay a 2×4 on some towels to avoid scratching the countertop. Run one end of the wood clamp through the drain hole. Place another 2×4 between the clamp and the sink to avoid damaging the sink. Tighten up the clamp to hold the sink in place.

Reattach the mounting brackets. Depending on the sink, the brackets may be attached to the countertop with epoxy or use a mounting system that anchors into the countertop and may require a specialty drill bit to drill the hole. Use a damp rag to wipe away any silicone that has oozed out into the sink.

Wait 24 hours for the silicone to dry before removing the clamp, installing the drain and hooking up the sink to the plumbing.