How to Plumb a Double Kitchen Sink With Plastic Pipe

Updated February 21, 2017

Double kitchen sinks offer extra space and aesthetics for your kitchen. Whether you install one for the first time in a new home or you're remodelling an older home to replace the existing sink with something new, double kitchen sinks can be installed by any homeowner with the proper tools, resources and spare time. While utilising two sink sections rather than one, the actual installation process and how the sink works is exactly the same as for a single-basin sink.

Familiarise yourself with the pieces in the kit. The "T" knuckle section is what each "J" piece (otherwise known as a tailpipe) attaches to, once they have been joined to the bottom of their respective drains on the underside of the sink (drain baskets), and is centred between the two drain holes. The sink trap is a U-shaped piece, and attaches to the wall drain pipe (a straight pipe sticking out of the wall on the back side of your cabinet) as well as the "T" section, to remove waste water.

Dry fit your entire installation before tightening the slip nuts (the circular nuts which are attached to each piece at the threads and join the plastic pieces together). First, attach the straight section of PVC pipe onto the wall drain pipe and join it to the sink trap (long, U-shaped piece), which in turn attaches to the "T" knuckle. The trap and knuckle should be directly under the sink, centred from front to back and side to side under the two drain baskets.

Cut off any excess pipe with a hacksaw. Loosely connect the threads of each piece with a slip nut to hold them in place while you make adjustments. After you have dry-fitted the drain pipe, sink trap and the knuckle, check to see if you need to cut off any excess of the tailpipe pieces. Cut them to fit by hacksawing the long ends of the tailpipes, then dry fit them to the sink baskets as well as the "T" knuckle.

Tighten all of the slip nuts to hold the installation together. Use a pair of Channellock pliers to tighten the nuts in place. Turn them in a clockwise motion. Avoid twisting them too tightly or you could crack the pipes. Apply just enough pressure to ensure a snug fit. Run water through the pipes and check for any leaks before using the sink.


All of your tools and materials can be purchased or rented from a local home-improvement store. Double kitchen sink kits are sold in a variety of sizes depending on the type of sink you install -- so talk to a professional in the store to ensure you purchase the right-sized attachment kit for your particular type of sink. While plumber's tape (Teflon tape) is not required for plastic installations (the threads and slip nuts work in conjunction to keep water in the pipes), you can use it for additional protection if you choose. Preassembled sink kits generally only require minimal adjustments, so measure twice and cut sparingly to avoid over-cutting.

Things You'll Need

  • Double sink plastic drain kit
  • Tape measure
  • Pencil
  • Hacksaw
  • Channellock pliers
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About the Author

Tim Anderson has been freelance writing since 2007. His has been published online through GTV Magazine, Home Anatomy, TravBuddy, MMO Hub, Killer Guides and the Delegate2 group. He spent more than 15 years as a third-generation tile and stone contractor before transitioning into freelance writing.