How to Attach a Faucet to a Sink
The easiest and best way to install a faucet is before the sink is in place. If you install the faucet before installing the sink, you won’t have to strain or reach because everything is completely open.
Most sinks come with factory-drilled holes along the back edge or lip. The number of holes should be equivalent to the number of holes needed for your faucet, so pay close attention when buying your faucet and sink. If you have a single-lever faucet, you’ll want a single- or two-hole sink, depending on whether your faucet needs a separate sprayer hose hole or if you want a soap dispenser on the sink.
Many sink and faucet combinations use four holes. In most cases, the first three holes from the left (as you face the front of the sink) are for the faucet. The hole furthest to the right is for a spray hose, separate water dispenser tap, or soap dispenser. Some newer sink designs have the holes positioned so that the dispenser hole is the one on the left, but this would be clearly marked on the carton or explained in the instructions.
Before you begin, create a stable workspace where you can safely position the sink. You can simply set the sink on a solid work surface, such as a workbench. Just remember to clean off the surface or put down some cardboard to prevent accidentally scratching the sink surface when it’s time to flip the sink over to tighten the faucet nuts. Or, if you want to avoid flipping your sink over, place it on a set of sawhorses. Just rest the side ends on the horses and you’re ready to have at it. Make sure that the sawhorses are stable and can’t slip or move. If a sawhorse moves, chances are good that the sink will fall.
It’s time to begin the assembly process:
Place the faucet over the three holes on the left with the faucet’s water supply tailpieces (threaded pieces located directly beneath the faucet handles) going into the two outside holes.
Screw the plastic nuts onto the threaded tailpieces, which will later connect to the supply lines.
Hand-tighten them until they are snug, and then use groove-joint pliers to finish tightening them. Be careful not to overtighten the nuts. Plastic nuts are easy to strip or ruin with pliers.
Seal the area where the faucet meets the sink, according to the manufacturer’s instructions.
Some faucets come with a rubber gasket that goes on the bottom of the faucet body between it and the sink. Other faucet manufacturers recommend applying a bead of silicone tub-and-tile caulk on the bottom of the faucet body before positioning the faucet on the sink. Both methods keep water from getting underneath the faucet, where it could run down the holes and drip onto the sink base cabinet floor.
At this point, you may want to install the sink baskets in the sink, but don’t do it just yet. (The baskets are the stainless steel strainer-like baskets used in kitchen sinks to let water run out but catch food scraps and other sink debris.) Leaving the baskets out keeps the holes open, and these holes are the perfect handholds for lifting and lowering the sink. Having these holes available also reduces the chance that you’ll grab the neck of the faucet and lift the sink, which can severely damage your sink.