Wash basins generally sit on top of the counter top and are held into position by silicone caulk around the underside rim. If the basin is going in a new unit, a hole must be cut to fit the basin. Wash basins are available in many colours to suit the surrounding aesthetic look of the bathroom, and can be shaped oval, circular, oblong and even hexagonal to suit your taste. The installation is fairly simple, and isn't time-consuming.
Place the basin upside down on top of a piece of cardboard. Run a pencil around the rim of the basin to create its perimeter on the cardboard. Draw a second perimeter 1/2-inch smaller than the first on all sides, then cut out this second smaller perimeter.
Place the cardboard on top of the counter in the desired position and trace around the hole onto the counter surface.
Drill a 3/8-inch starter hole through the counter top at one point on the pencil line. Insert a jigsaw into the hole and cut around the traced line to create the hole for the basin.
Apply a 1/3-inch bead of plumber's putty to the underside edge of the base of the faucet. Push the faucet tail pieces down through the holes on the side of the basin. Push the faucet down against the basin so that the putty creates a good seal. Screw on the metal friction washers to each of the tail pieces, and also thread on the mounting nuts. Tighten the nuts with water-pump pliers. Remove any excess putty from the faucet base.
Apply a silicone-caulk bead onto the counter top all around the edge of the cutout hole. Slowly lower the basin down into the hole, pressing it down so that the caulk creates a good seal. The P-trap and flexible water supply hoses can now be installed.
Wait for the silicone caulk to dry completely before using the basin. Look at the caulk directions for required drying time.