Preparing to Install a Kitchen Sink
Much of the work of sink installation takes place before you set the sink into the countertop. Taking your time with the preliminary work ensures a smooth installation. In most cases, the old plumbing configuration will work with your new sink. But if you’re making a major change in the design of the new sink, be sure that the old plumbing fits the new sink’s requirements. So, before you buy or order a sink, take a few measurements:
If you don’t install your sink and faucet according to the instructions, you’ll have to foot the bill for the replacement even if the product is defective. If the manufacturer sees signs of abuse or misuse or an improper installation, they’re off the hook.
Establishing the drain height: Make sure to measure the distance from the underside of the countertop to the center of the drain line that comes out of the wall. This distance is usually between 16 and 18 inches, which allows adequate space for the water to drop into the trap and still leaves enough space below the trap for storing items underneath the sink in the cabinet.
The drain height is usually not an issue unless you’re going from a very shallow sink to one that has very deep bowls (9 to 12 inches deep). Even if you do switch to deeper bowls, it may only be a problem if your old setup had a shallow bowl coupled with a high drain exit position. This may sound like a less than likely setup but it does happen.
If you do find that you only have a few inches of space between the bottom of the bowl and the center of the drainpipe, contact a licensed plumber to assess the situation and determine if the drainpipe needs to be lowered.
Determine the shut-off valve heights: Measure from the floor of the sink base cabinet to the center of the valve.
Houses built before roughly 1980 were not required to have shut-offs on every sink supply line, so you may not have any at all. If your sink doesn’t have shut-off valves, install them now while you’re working on the system. If your kitchen didn’t have shut-offs when you tore out the old sink and faucet and you’ve been working on the sink installation for a few days, you better have installed individual shut-off valves by now or your family won’t be speaking with you. Where there are no shut-off valves and there are open pipes or lines, the only way to keep the water from running out is to shut down the entire water supply. Not a good idea when your daughter is getting ready for a big date.