How to Plumb a 3 Compartment Sink

A 3 compartment sink is a basic necessity in our homes, public places, or in a restaurant. After installing the sink, you may want to plumb it. Understanding how to plumb a 3 bay sink in your kitchen or restaurant is quite important.

Plumbing these sinks sometimes become a challenge, but with the correct parts and some plumbing experience, you can do it. Plumbing this sink varies depending on the style and setups of the sink.

It is also essential to consult with a plumbing contractor so that you may understand what you need before the process. You may also need to mix and match some pieces to get a stronger and proper installation.

6 Steps to Plumb a 3 Compartment Sink:

Step 1: Plan the path of the pipe

The first step into plumbing your 3 compartment sink is to plan the path of the pipe. Start the preparations by running a sizable drain pipe that is about 2-inches under the floor from the main waste stack into the cabinet housing the sink.

Make sure this is the shortest path possible before physically removing the flooring to lay your pipe. After you have finished laying down the pipe into the cabinet housing your 3 compartment sink, you will need to extend the pipe up to about 5-inches underneath the sink.

Step 2: Separate all pieces

Put aside each part of your 3 compartment sink kit. This kit contains the center tee, elbow, and drain tailpiece sections. The elbow section connects the right and left bowls while the center tee connects the center drain with the two drain tailpiece.

Step 3: Mark the cuts

Put in the sink drain and its tailpiece that comes off the drain. The P-trap assembly will attach to the piece. Make sure you connect the PVC extension pipe to the end path of the P-trap.

Carefully move the P-trap around together with the extension until it touches the drain pipe. Mark the places to be cut on the two pipes. Using a hacksaw, cut the drainpipe in the places you marked and remove any burrs using sandpaper.

Step 4: Cut your PVC pieces

Using a hacksaw, cut the drainpipe in the places you marked and remove any burrs using sandpaper. When cutting the PVC pieces, ensure they fit the places you had marked.

Do a thorough check on your wall to see where the drain is. You may not need additional pieces to install center set -drains as it installs directly to the p-trap kit.

In the case of offset drains, you must first install a p-trap kit followed by a flexible extension that will drain water outside the wall. This drain should be flexible for it to curve around so that it may line up with the outlet on the wall.

Step 5: Install the sanitary tee and PVC p-trap

Position the tee while the sweep faces up and its outlet pointing towards the P-trap. Make sure the outlet has the same size as that of the extension pipe. Attach the tee to the drainpipe using the PVC cement. Connect the tee and extension pipe.

You can now install your p-trap kit on the center -set tail’s bottom, aligning it with the wall. If there is a need, you can use the tailpiece extensions to your sink’s drain’s bottom.

Step 6: Check for the leakages

If there is a need, you can install the tailpiece extensions to your sink’s drain’s bottom. Check if there are any leakages and, make sure you tighten all the connections.

How to Install a 3 Compartment Sink in a Garage

If you are the kind of person who does not like a dirty home, then you can install a 3 compartment sink in your garage.

Installing sink in the garage will help you avoid walking to the kitchen sink that can lead to the soiling of your carpet or floor. The steps below will guide you appropriately to install the 3 compartment sink in the garage.

Step 1: Prepare the pipes

This is a step that you should never miss. Ensure you shut the main water valve to prevent water from wasting. It is important to install your sink near cold and hot water pipes and where drainage is adequate.

Measure and mark the drain pipe and the cold and hot water pipes. This will help you to cut a portion of them to install a Y-shaped fitting and a ‘T’-shaped fitting respectively.

The fittings are necessary as they create hook-ups within your plumbing that ensure there are good drainage and water supply to your sink.

Step 2: Create the hookups

Cut the drain pipe using a hacksaw but use a tube cutter to cut the water pipes because most of them are made of copper material. You will need some glue and primer for your PVC drain pipe to connect it to the Y fitting.

Fit the p-trap kit to the Y-fitting of the drainpipe to attach it to your sink. You can then melt the solder that is in between the T-fittings and the copper piping using a torch, solder plus soldering iron, or a flux.

Step 3: The sink

Place your sink beneath your new PVC trap. Use a compression nut to secure the pipes connecting the sink and the trap. Do not forget to attach flexible hoses to the faucet’s bottom. This allows cold water and hot water to freely move across the assembly.

Remember to generously place the plumber’s putty on the faucet of the bottom of the sink before attaching it to the surface.’

Step 4: Recheck the water connections

Attach the flexible hoses to the T fittings of the cold water and hot water. Check to see whether all the connections are safe then turn on the water valve to confirm if the sink is working.

In case there are leakages, you can turn off the water and check if there are lose connections. Tighten every loose connection and, at this point, you can freely use your 3 compartment sink.


As we have seen from the steps above, plumbing a 3 compartment sink and installing it is not a hectic process. This means you can choose to do it by yourself or if not, you can engage a plumber who will do it better for you.

Installing a 3 compartment kitchen sink is better than a single compartment one because it will save you space while doing the washing. The first compartment helps you to remove dirt by scrubbing, you then rinse using the second compartment then sanitize using the third compartment.

Restaurants are in a dire need of these sinks because they always offer an alternative dish-washing method especially if the ware-washing equipment stops working. To ensure that your sink is in good condition always, make sure your dishes have no leftover foods before putting them on the sink to wash them.

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