Whether installing a bathroom sink or a kitchen sink, the procedure is basically the same.
There are three basic types of counter sinks used in bathrooms and kitchens:
The first step in any sink removal/installation is shutting off the water supply. If the water supply lines under the sink do not have shut-off valves on them, now is a good time to have some installed.
Reasonably priced, high-quality flexible vinyl hose kits are available in most hardware or building supply centers. Be sure to size fittings accurately for both the supply lines and faucet fixtures. Installing shut-off valves in supply lines will make future sink installation and maintenance easier and handier. It will also provide quick access for emergency shut-off.
If you are replacing an old sink with a new one into an existing counter top opening, you will need to install one that is the exact same size as the old.
After removing the old sink, check the counter top for any water damage and rot. If any is detected, make necessary repairs. If the extent of damage warrants it, replace the old counter top with a new one.
Follow these steps for installing the sink:
If you are installing a sink for the first time into the counter top, it is necessary to take careful measurements for proper placement of the sink and opening. Be sure to leave at least 1 ½ inches, but not more than 3-inches from the edge of the counter.
Once you are sure of placement, place the sink upside down on the counter top, and mark around the perimeter of the rim. Be sure that the edge of the rim is parallel to the edge of the counter top. Remove the sink, and mark a second line about 1½-inches inside the first mark. Note: if another measurement is specified in manufacturer’s instructions for any given sink, use that one instead.
Since a jigsaw (reciprocating saber saw) is used to cut along the inside mark, you will need to drill a hole just inside of the inside line at each corner big enough to insert the saw blade. It is best to put masking tape on the bottom of the saw to avoid scratching or other damage to the counter top.
Cut carefully, staying on the line. Do not allow the saw to wander off of the line. When the hole is finished, insert the sink, and check the fit. Make sure the sink is properly aligned.
Self rimming sinks without clamps are dropped into the opening and caulked into place. Finish installation following the 4 steps previously listed.
Recessed or undermount sinks are installed to the bottom side of the counter top before the counter top is installed. This type recessed sink/countertop arrangement is readily available in a variety of pre-manufactured kits; the sink and pre-cut counter top come ready to assemble. Some kits even come with the sink already installed.
Caulk the edge of the sink, and put it into place. Screw it down using the hardware that came with the sink, following manufacturer guidelines. Once the sink is in place, the countertop installed and sink faucets attached and secured, follow previously listed steps 3 and 4 to connect supply lines and drain.