Undermount Sinks
Updated February 20, 2026
Installed beneath the countertop for a seamless, modern look. Makes countertop cleanup easy as debris sweeps directly into the sink.
Overview
Undermount sinks attach below the countertop surface with clips and adhesive. The countertop edge is exposed directly over the sink basin -- no rim. This creates a clean, seamless look and makes countertop cleanup easy (just sweep crumbs directly into the sink). Requires a solid countertop material: granite, quartz, marble, or solid surface. Laminate countertops cannot support undermount sinks because the exposed particleboard edge absorbs water. The most popular choice for modern kitchens with stone or quartz countertops.
Pros & Cons
- Clean appearance
- Easy countertop cleanup
- Modern look
- Requires solid countertop
- Professional installation recommended
- More expensive
Key Features
- Mounts below the countertop for a seamless, rim-free appearance
- Easy countertop cleanup -- sweep directly into the sink
- Requires solid countertop material (granite, quartz, marble, solid surface)
- Secured with clips, brackets, and adhesive (epoxy or silicone)
- Available in stainless steel, granite composite, fireclay, and copper
Sizing & Selection
Same sizing as drop-in: 33x22 standard, 25x22 small, 36x22 large. The countertop cutout is sized to the sink bowl (not the rim), so it is slightly smaller than a drop-in cutout. Bowl depth 8-10 inches. For new countertops, the fabricator cuts the opening to match your specific sink model.
Installation
Countertop must be fabricated with the correct cutout and edge profile. Sink mounts from below using clips that attach to the underside of the countertop with epoxy (for stone) or screws (for solid surface). Silicone caulk seals the sink rim to the countertop underside. The sink must be supported during adhesive cure (24 hours). Professional installation recommended for stone countertops.
Maintenance
- Clean the sink-to-countertop seam with a toothbrush and mild cleaner -- mold and buildup accumulate in this joint.
- Reseal the edge with silicone caulk if you see gaps or the seal starts to peel.
- Stainless steel: clean with the grain. Bar Keepers Friend removes stubborn stains and restores shine.
- Granite composite: extremely durable. Clean with soap and water. Mineral deposits wipe off with vinegar.
Buying Tips
- Granite composite (-500) is the most durable undermount material -- scratch, stain, and heat resistant. Brands: Blanco Silgranit, Kraus Quarza.
- Stainless steel (-400) is the most affordable. 16-gauge or 18-gauge for undermount -- thinner gauges flex.
- If ordering a new countertop, buy the sink first and give it to the fabricator. They cut the opening to match.
- Low-divide double bowls give you the best of both worlds -- two basins with a low wall that allows large pots to span both sides.
- Always verify the sink model has undermount clips included. Some sinks are sold as drop-in only.