How to Install Undermount Sink

Undermount sinks have become commonplace in most new homes for their convenience, beauty and simplicity. Unlike conventional sinks that use a lip at the edge to hold the bowl in place, undermount sinks are essentially contiguous with the surrounding material. That means everything from cutting boards to plates can be wiped into the available space without having to worry that you are jamming organic debris into the cracks.

Installing an undermount sink is exceedingly simple, provided that you follow a few basic guidelines. Without question, the most important is to use a countertop made of solid material; stone, marble or granite. Anything less and the moisture that comes with this kind of design will inevitably find its way between the layers of your laminate or composite countertop. A solid edifice comes with no such risk, though you still must take care to seal everything properly if you want to enjoy years of flawless performance.

The first step in this process is choosing what kind of sink you want. Many newer homes come with double-bowl sinks for convenience, and an increasing number are deeper than they were in years past. If you frequently wash glasses, you may also want to get a basin that is nearly level at the bottom since more than a few homeowners have lost pricey stemware because of slick surfacing. Also consider whether you would like soap dispensers, filters or other hardware that may need to take up residence under the countertop, as additional drilling may be required.

When you are ready to begin, you will most likely need a professional to cut the hole for you. If you have the right tools for the job, however, there’s no reason to hand off menial labor such as this to a pricey contractor. A sharp saber saw and a steady hand can make a clean cut, and a keyhole saw can help clean up any edges. As with all cutting equipment, be sure and wear goggles and a dust mask to protect your face and lungs from flying particles.

Next you have to attach the sink securely to the countertop. Flip it over and locate precisely where you will need to mount the sink screws, as each manufacturer offers a slightly different design. Mounting screws also come in different gauges and strengths, so you may want to check at your local hardware store to ensure they can handle the materials involved. When you are done drilling leads, be sure and clean every part of the area with rubbing alcohol as natural minerals and open fissures can let in bacteria that will corrode the metal fasteners in your sink.

Next you want to create a flawless seal using latex or plumber’s putty. Too much is better than too little here, though it is most essential simply to cover every inch of that perimeter. Excess can always be wiped away, but resetting a sink in this manner often requires powerful and caustic solvents to remove it from its perch. Press the sink into place with a steady hand, being sure to cover the sides completely as well as the corners. If the sink has any erratic curves, these will require measured pressure all the way around.

Screw the mounting screws back into place and leave the project overnight to set. When it is completely secure, flip the countertop over again and re-attach it to the base counter, using caution to ensure the extra weight is supported sufficiently. If everything looks good and the sink is flush with the counter, you can finish the job with a bit of rudimentary plumbing. If you aren’t familiar with how to attach drain pipes, now would be a good time to check with an expert to ensure you don’t create any new leaks.

Attach the sink drain and S- or P-trap using plumber’s putty and new screws, giving each time to set adequately. When everything is in place, you can add the finishing touches like flexible pressure lines, soap dispensers and any intermediate parts such as a water filter. This entire process can be completed in a matter of days, and the savings may be significant. Best of all, you come away with a kitchen countertop as handsome as it is practical.

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