What Plumbing Designers Need to Know About Selecting Sinks

Kitchen/break room sinks have multiple options that need to be taken into account along with budgetary constraints to make an informed decision for the client.

by Siddharth Bhat, PE, CPD, GPD, LEED AP 

In this series of articles on plumbing fixtures, we move on to the next step of selecting a sink. Generally speaking, sinks can come in different types—from kitchen sinks to service sinks and mop sinks, etc. Each of these sinks has different features that need to be considered based on the utility of the space, aesthetics, and more.

To help the plumbing designer better understand how to select certain types of sinks, this article focuses on kitchen/break room sinks.

Kitchen Sinks

Kitchen sinks are used mainly for culinary purposes. They can be classified as residential or commercial based on the extent of usage. However, one may be able to use a residential sink in a commercial setting. For example, in a break room in an office space, one may not expect major cooking activity to take place; the sink would primarily be used for utensil cleaning and handwashing, so the designer may provide a residential kitchen sink even in this commercial setting.

These types of sinks typically have a single bowl or a double bowl. Single-bowl sinks are ideal in cases with restrictions in the amount of space available. With double-bowl sinks, one bowl can be used for cleaning with the other being used for rinsing.

Where allowed, it is good practice to provide a small garbage disposal below the sink to prevent the drain from clogging. In an office setting, employees may wash dishes containing different types of food items with bones or other hard materials. Having a garbage disposal ensures that these food items are broken down into smaller pieces that can be easily drained, ensuring a clean sink.

Top-Mount, Single-Bowl Sink

Kitchen sinks most commonly are installed in two ways: top mount/drop in and undermount. (Other installation methods such as farmhouse and apron are beyond the scope of this article.) Like the name suggests, a drop-in sink rests on the kitchen countertop after it is lowered into the casework cutout. One of the benefits of this type of sink is that it is easy to install, thus saving on installation costs. The disadvantage is that residue can accumulate in the gap between the sink’s surface and the kitchen countertop, which can be difficult to clean.

Undermount, Double-Bowl Sink

On the other hand, an undermount sink is installed from underneath the countertop. These sinks are further divided into three types depending on the exposure of the sink rim: positive reveal, negative reveal, and zero reveal. With a positive-reveal sink, some amount of the sink rim is on top of the countertop. With negative reveal, the sink rim is completely under the countertop, while with a zero-reveal sink, the sink rim aligns with the countertop surface. Unlike a drop-in sink, this sink is harder to install, thus leading to more installation costs. However, it does not present sanitary issues around the sink countertop like with a drop-in sink.

Most kitchen sinks are made of stainless steel, although other materials such as copper, porcelain, granite, cast iron, and composite are also used. Stainless steel sinks are preferred because they are lightweight, durable, and easy to clean. Sound-deadening coatings and pads are also available to ensure that noise is reduced when the sink is in operation.

Another factor to consider when selecting a kitchen sink is the depth of the sink bowl. A deep sink bowl gives the user more space for washing dishes, etc. However, one also needs to coordinate the space available in the casework below the sink, especially when accessory equipment such as a garbage disposal or hot water dispenser is included. The designer also needs to determine if the sink needs to be ADA (American with Disabilities Act) compliant. These sinks usually have a smaller bowl depth as compared to a standard sink.


Another important aspect of sink selection is selecting the accompanying faucet. The designer needs to specify the number of faucet holes for the sink: single hole or three hole. Three-hole faucets typically are 4 inches on center or 8 inches on center, and the distance on center for both the faucet and the sink bowl must match.

Pull-Down Faucet

Another main factor to consider is the span of the sink vs. the span of the faucet. If the span of the faucet is more than the span of the sink, water may spray out from the sink and wet the surrounding counter. Ideally, the span of the faucet should match the location of the drain to ensure that water is directed quickly into the drain.

The two major categories of sink faucets are pull down and pull out. Pull-down faucets have a built-in hose that can be extended, which allows the user the flexibility to move the faucet around to clean all parts of the sink. This feature also makes dishwashing easier as it allows users to adjust the hose as needed to remove food particles from dishes. Due to the presence of the built-in hose, these faucets typically have a high neck arch, allowing more room to place tall pots, pitchers, etc., in the sink to be filled or cleaned. However, the high neck arch increases the span of the faucet, making it unsuitable for small sinks.

On the other hand, pull-out faucets have small spouts, making them suitable for smaller sinks. They do not provide the same amount of flexibility as a pull-down faucet, but some do allow for rotation off their main stem for cleaning purposes.

Pull-Out Faucet

Faucets may be manual or automatic, and multiple advances have been made in the field of automatic faucets. Some have a push button to change the water flow, and the water may come out as a spray or a stream, thus allowing users the flexibility to determine the flow based on the type of cleaning required. The user can use the stream function to remove stubborn messes instead of using the spray function, thus preventing splattering along the sink. Some manufacturers now also provide a voice function to turn the faucet on and off, so the user does not need to touch the faucet with dirty hands. Another advancement is the ability to set a timer on the faucet. Depending on the size of the vessel, the user may set the time needed for the vessel to be filled with water, which ensures that the user does not need to wait near the sink for the vessel to be filled completely. On other newer faucets, the user can touch the faucet anywhere to turn it on and off.

In conclusion, kitchen/break room sinks and faucets have multiple options that need to be taken into account along with budgetary constraints to make an informed decision for the client.

About the Author

Siddharth Bhat, PE, CPD, GPD, LEED AP, is a Mechanical and Plumbing Engineer at DLZ Corporation with specialization in correctional facility design.

The opinions expressed in this article are those of the author and not the American Society of Plumbing Engineers.

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