How to Install a Garbage Disposal in a Double Sink

Having a double-bowl sink in your kitchen gives you a lot convenience when you’re washing dishes by hands.  How to Install a Garbage Disposal in a Double SinkThe sink becomes even handier when it’s fitted with garbage disposal. However, installing the garbage disposal can be a bit challenging.

In this guide I’ll take you through a step-by-step guide on how to install a garbage disposal in a double sink.

Related: How to Unclog a Garbage Disposal with Standing Water

Advantages of a Double-Bowl Sink

1. Separate Sink for Garbage Disposal

Having a double-bowl sink gives you a convenient space for discarding food waste during food preparation and after meals. Usually, double-bowl sink comes with small and big bowl. The garbage disposal is mounted on the small sink while larger sink gives adequate space for putting unwashed dishes.

2. Ample Space for Soaking and Washing Dishes

The big bowl provides adequate space for soaking your dishes after dinner so that you can work on them in the morning. During washing, you can use the smaller bowl to rinse your dishes.

You can also use the big bowl to fill water during deep cleaning.

Steps for Installing a Garbage Disposal in a Double Sink

Step #1 – Install the Drain Flange

The garbage disposal unit comes with a flange which is first installed on the sink. It’s mounted on the drain entrance so that it provides an extension on which the garbage disposal can be attached. Here, the steps to take.

You can choose between the 3-bolt or EZ mount disposals. Below are 4 easy steps for installing the sink flange.

  • If you’re doing a replacement, ensure you unplug the garbage disposal from the power to prevent accidents.
  • Make a roll, about ½ inch diameter using the plumber’s putty. Roll the putty on the sink flange.
  • From above the drain entrance, insert the sink flange and press it down until it touches the sink. If you’re making a replacement, first remove the existing flange and scrap off the old putty.
  • Place a towel on the flange and add some weight on it so that it can press down on when you’re installing the mounting flange beneath the sink.
  • A for 3-bolt mounting, loosen the bolts and remove the snap ring. Then insert it on the sink flange, fix the snap ring and tighten the bolts snugly.
  • With the EZ mount, screw the mounting flange on the sink flange and tighten snugly.

Step #2 – Connect the Power Cord

If the power cord isn’t already attaches to the garbage disposal, then you’ll have to do the connection. Usually, garbage disposals comes with an easy to use manual indicating how the wires should be connected.

Notably, the wires have different colors which match with their corresponding colors on the garbage disposal. This is meant to eliminate guess work when connecting the wires.

  • Use your screw driver to open the lid which is located on the underside of the garbage disposal.
  • Armed with your wire strippers and clamp connector, connect the wires and place back the lid. Ensure that the wires do not touch other to avoid short-circuiting.

Step #3 – Knock out the Breakout Plate

If you have a dishwasher, knockout the plastic plate that initially closes the dishwasher connector. All you need is a screwdriver and a mallet or hammer.

If you don’t use a dishwasher, then the breakout plate should not be removed.

Step #4 – Mount the Garbage Disposal

If you’re replacing a garbage disposal, then you know that your sink cabinet has ample space for the new one. But if you’re installing a garbage disposal for the first time, then measure the unit and the available space to ensure it fits conveniently.

Step #5 – Install the Pipes

Having mounted garbage disposal, now it’s time to do the pipework so that both sinks are connected to the main drain through one pipe. Follow the steps below to install the pipes.

  • Install the tailpiece on the large sink. First, place the tailpiece washer and connect the tail piece using the slip nut.
  • Connect the PVC Tee to the tailpiece in such a way that the perpendicular end points to the garbage disposal.
  • Connect the tailpipe to the garbage disposal. The unit comes with a rubber seal on which the tailpiece can be attached. Then, insert the metal ring to secure the tailpiece in place.
  • Connect the PVC Tee to the garbage disposal using an elbow and the flanged extension.
  • Connect the P-trap to the remaining end of the Tee. Later you’ll connect the P-trap to the drain pipe.
  • With the dishwasher, connect the dishwasher drain horse and fasten with the retaining clamps
  • Finally, tighten all the connections snugly. Run water through both sinks to ensure there is no leakage.


Though there’re many connections to do, installing a garbage disposal in a double sink isn’t that complicated. When you approach it step-by-step it becomes easy to assemble.

All you need is the right tools and know how to measure pipe lengths. The pipes and fittings come with couplings which makes it easy to connect to each other.

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