Many homeowners choose a concrete counter because it is a solid surface. There are no grout lines and the counter is smooth and seamless with clean lines. However, a drop-in sink will cover up a few inches of the concrete and detract from the smooth and seamless appearance you are trying to achieve. An undermount sink leaves as much of the counter exposed as possible and will let the solid surface concrete counter be the star of the kitchen.
Things You'll Need
- Stiff-bristled brush
- Silicone caulk
- Two-part epoxy
- Masonry drill bit
- Safety goggles
- Concrete screws
Brush the underside of the counter, where the sink will be installed, with a stiff-bristled brush to remove dust and debris.
Trim a 2-by-4 with a saw so it is 6 inches wider than the sink. Lay the 2-by-4 across the top of the open space in the counter.
Spread silicone caulk on the flat lip of the sink. Press the sink into the underside of the counter. Slide a G-clamp through the drain hole in the center of the sink and around the 2-by-4. Adjust the sink until it is perfectly lined up with the hole in the concrete counter.
Tighten the clamp to secure the sink to the concrete.
Open the cabinet doors and slide under the sink on your back. Hold the undermount clips on the edge of the sink so that the hole in each clip lines up with the underside of the concrete counter. Make a mark through the holes in the clips with a permanent marker. Plan to place two clips on each side of the sink.
Put on safety goggles to protect your eyes from debris. Drill holes in the concrete with a masonry drill bit. Coordinate the size of the drill bit with the size of the screw. Drill a hole through all of the marks in the concrete. The length of the screw should be shorter than the height of the concrete.
Combine two-part epoxy following the package instructions. Apply the epoxy to the lip of the sink. Press the undermount clips into the epoxy so they line up with the pre-drilled holes. Let the epoxy set for five to 10 minutes.
Insert a screw through each clip and into the holes. Wait 24 hours before you connect the plumbing, faucets and disposal.