A second sink in the master bathroom makes it easier when two people share the bathroom.

How to Add a Second Sink in a Vanity

by Gary Sprague

Adding a second bathroom sink in a vanity can reduce bathroom bottlenecks, as two people get ready for work or a night out at the same time. If you are sick of seeing your husband’s whiskers in the sink every morning, adding a second vanity sink can correct the problem. By placing a second sink next to an existing one in a vanity, it allows you to tie into the same plumbing, which saves both time and money.

Sink Selection

A homeowner has multiple sink materials and mounting styles to choose from when purchasing a second bathroom sink. When making your selection, match the sink and the same style of faucet already in place. If the original sinks and faucets show some age, or if you cannot find a match, purchase two sinks and faucets to get a matching pair. When adding a second sink to the vanity you want the sink and fixtures to match for decorative appeal.

Cut the Countertop

The sink you purchase comes with a template for cutting the countertop. Set the template on the chosen vanity location. Mark it with a pencil. To avoid installing another drain line, install the second sink 30 inches from the center point of the existing sink. Cut a laminate vanity top with a jigsaw. A solid-surface countertop requires the use of a wet saw and a diamond-tip blade, depending on the material. Use caution when cutting through these countertops, as they run the risk of scratching or chipping when cut. Contact a professional to safely cut the countertop if you or a family member cannot do it. To minimize cutting, you may want to install bowl sinks that sit atop the countertop. Avoid mounting a sink beneath the countertop when using laminate.

Purchase a Countertop

You can also purchase a preformed vanity countertop. These sinks contain preformed sinks in the vanity top and require no cutting. A preformed vanity top makes for an quick installation, as you do not need to install the sinks separately, and it gives you a large selection of styles, colors and materials from which to upgrade your bathroom. Disconnect the plumbing to the original sink to remove the old countertop. Take careful measurements to ensure the new countertop fits your vanity.

Install Plumbing

You also need to install new plumbing for the second sink. Tie the water and drain lines for the new faucet and sink into the existing plumbing beneath the vanity. You need to add a separate drain line and trap for the second sink, especially if the distance between them is more than 30 inches from sink center to center, otherwise cut into the existing drain lines and connect them together. Install separate shut-off valves for the new sink after adding a tee fitting and piping to the existing hot and cold feeds. Check with your local building jurisdiction to determine if the additional sink requires a separate vent line.

About the Author

Gary Sprague is a master plumber with more than 25 years of experience. His articles have appeared in many online and print publications.

Photo Credits

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