Double sinks are extremely helpful in any household, providing additional space for dishes and general washing. If you’re preparing to learn about double sink plumbing and thinking of installing this type of sink in your kitchen, follow our step-by-step guide for an overview of the process.

1. Install Sink Strainers

Place the plumber’s putty or silicone caulk under the basket strainer, then lower it into the sink’s drain. Secure the strainer to the sink by tightening the strainer nut from the bottom. For the second sink, repeat the process and allow the silicone caulk or putty to set for a few minutes.

2. Install the Sink

With the strainers installed, now it is time to place the sinks on top of them. Please note, that the position of the sinks will vary depending on whether you have a drop-in or under-mount sink.

Drop-in sinks should sit on top of the counter so that the edges help support the weight. If your sink has clips, you’ll need to secure them with a screwdriver.

Installing an undermount sink requires that the edges be secured to the countertop. Secure the sink with heavy-duty clips to keep it in place.

3. Measure the Height of the Drain Outlet

Measure the height of the drain outlet pipe with a tape measure. Ideally, it should be high enough from the ground for the P-trap to be installed, and low enough to allow for the connection of the drain tailpieces and sanitary tee.

4. Connect Drain Tailpieces

Once you’ve determined that the height of the drain pipe is at the appropriate level, attach the drain tailpieces to the basket strainers. With your channel locks, tighten the plastic nuts.

5. Install the Sanitary Tee

Connect the drain tailpiece to the 90-degree sanitary fitting and attach it to the horizontal piece of PVC pipe. After that, connect it to the sanitary tee that should be in the middle of the sinks.

6. Install the Drain Trap

Connect the sanitary tee to the U-shaped trap. With that done, connect the U-shaped trap to the J-shaped trap. At this point, the drainage line is complete.

7. Mount the Faucet

Run the faucet mounting bracket along with the hot and cold water lines through the countertop. Tighten the nuts on the bottom of the faucet to secure it to the counter.

8. Connect Hot and Cold Water Lines

With the hot and cold water lines under the sink, you can now match them to the hot and cold water pipes under the sink.

9. Check for Leaks

Now that the water lines are all installed and secure, you will need to test your work. Turn on the hot and cold isolation valves. Then turn on the faucet to let the water flow into the sink. At this time, inspect each part of the sink for potential leaks. Make sure that the pipes are all dry while the water flows through.


  • It is important to measure the area where you plan to install the double sink to ensure that the larger sink will fit there.


  • Make sure to turn off the hot and cold isolation valves under the sink during the installation.

Tools Needed

  • Tape measure
  • Hacksaw
  • PVC pipe cutter
  • Channel locks
  • Marker
  • Caulking gun
  • Screwdriver
  • Double Sink
  • Compression nuts
  • Washers
  • Plumber’s putty or silicone caulk
  • Sanitary tee
  • PVC pipe
  • Teflon tape or silicone sealant
  • Kitchen drain trap kit
  • Sink drain and strainer assembly
  • Faucet

If you don’t have the time, tools, or ambition to tackle the job yourself contact Erica's Plumbing, Air Conditioning & Restoration & Restoration and schedule professional service in the Boca Raton area. 


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