How To Install A Garbage Disposal In A Double Sink?

Installing a double sink in your kitchen will bring tons of benefits. You will have more organization, a cleaner sink, and more comfort.

But while it is super practical, a double sink can be challenging to install. And when you consider mounting garbage disposal for it – that’s when it gets genuinely challenging.

Garbage disposals are super helpful as well, but they can be a headache to mount. Unless you have experience doing so and know exactly what to do – this will become an extra-difficult job.

Don’t worry, though. We know precisely what you can do to make this possible and install the garbage disposal in your two-bowl sink. Want to know how we can help you make that happen? Then read up!

Installing a Double-Sink Garbage Disposal in 9 Steps

You won’t need to spend days trying to install a garbage disposal on your double sink. But you will need to follow specific steps to make that possible. Here we have everything you need to know:

Things You Will Need

• Plumber’s putty/silicone caulking
• Adjustable pliers
• Screwdriver
• A level
• Pipe cutter or hacksaw
• A PVC drain tailpiece
• A PVC tee
• A PVC flanged extension pipe
• A PVC p-trap assembly
• A drain/p-trap adapter

You can find all these materials on Amazon, here:

They are for either adjusting or piecing up the entire drain unit together. It is necessary to have each one of these items if you want to install your garbage disposal without problems. Then, you can proceed.

1. Install the Drain Piece

This is the first thing to do – install the small drain tube that will connect the garbage disposal with the sink. Here’s how:

•  Set up the drain assembly of the sink. Remember to piece it up well with the sink drain hole, so it doesn’t fall or move. Tighten the fittings well with your hands.
• You can always add putty or silicone to seal the connection between the pipes and the drain hole. This will prevent any leak.

Once you’ve successfully connected the drain, you should let the putty or silicone dry for a few minutes. Then you can keep going.

2. Adjust the Sink

You will need to make sure that the sink is in the right place before you start installing the garbage disposal. Remember, it should be well-connected but also in the right place to prevent any unlevelled surface.

• Place the sink on the opening in the cabinet/countertop. Use the level to make sure that it is appropriately placed.
• Measure how much space there is below the sink, and make sure the garbage disposal fits inside without problems.
•  Tighten it up to the area using the clips. Then use the screwdriver to tighten these clips. This will fix the sink to the countertop or cabinet.

Now that you’ve done this, it is time to add the garbage disposal into the mix.

3. Install the Garbage Disposal

Most garbage disposals are small enough to fit inside cabinets or countertops without taking much space. But still, you need to make sure that it fits. Then, you can proceed to finish the installation. Here’s how:

• Measure the garbage disposal unit, measure the drain fitting you installed in the first step and check whether they both fit below the sink. If they do, then keep going.
•  Then follow the instructions of the machine manufacturer. This will help you prevent any problem and make sure it fits inside.
•  Make sure the garbage disposal ends up in the holder. Remember to use the wrench, screwdriver, and other tools if needed.

By now, the garbage disposal is in place, so you can proceed to connect the rest of the drain and other pipes.

4. Connect the Tailpiece

With the garbage disposal in place, you can start with the tailpiece. This is a small piece of PVC that attaches the machine to the sink drain directly. Here’s how to connect it:

•  Look for the threaded part of the drain outlet in the sink. Then piece it up with the tailpiece. Make sure the tailpiece adjusts well to the small tube on the drain.
•  Some tailpieces come with nuts that need to be adjusted with the drain assembly. Add this nut to the equation and install the tailpiece.

This will give space for the rest of the drain system to be installed.

5. Install the PVC Tee

A PVC tee is a part that comes with an inlet and two outlets. Its whole purpose is to divert one water source into two paths. This one goes directly into the tailpiece. And this is what you need to do:

• The drain system probably has an additional compression nut. Slide it into the tailpiece and adjust a compression washer by hand. Here, you will install the PVC tee.
•  The perpendicular side of the tee should face the garbage disposal. The other should face the second drain.

Once you install the PVC tee, you can proceed to install the flanged extension.

6. Add the Flanged Extension

This extension is the part that connects the PVC tee with the disposal unit. You will need an extension of the right length for this to work.

• First, start by measuring the space between the tee and the disposal unit. Then take this measurement and cut a PVC flanged extension accordingly.
• Now slide a disposal washer rubber into the end of the extension. Then push a mounting bracket to piece up the extension into the disposal unit.
• Finish by connecting the extension to the PVC tee. Do this with a compression nut. You can do this by hand or using the wrench.

Now you have the PVC tee connected directly to the garbage disposal. You’re almost finished.

7. Mount the Disposal Outlet

While the disposal unit is almost entirely connected to the sink, you still haven’t mounted it to the disposal outlet. Here’s what you need to do to make that happen:

• Grab the pipe of the machine and tighten a compression nut into it. Then connect the flanged part of the extension to the disposal outlet.
•  Finish by fixing the mounting bracket and the screws. This will piece up the disposal outlet to the sink and extension.

By now, you’re only left to connect the P-trap to the disposal unit.

8. Mount the P-trap

The P-trap connects the tee to the unit. This is necessary if you want to have the garbage disposal working well. Here’s how:

• Grab the P-trap kit and start connecting the main pipe into the PVC tee. You should connect it to the outlet that points to the side towards the disposal unit.
• Then proceed to tighten everything by hand. Remember to use compression nuts to make this fast and easy. Use the wrench if needed.
• Finally, rotate the trap until it meets with the disposal unit outlet. Connect them together using a compression nut once again.

You’re left to just connect the entire system to the inlet in the wall, so the residues go directly into the drain.

9. Tighten Everything Up & Check

You’ll have to tighten everything up and do a test to see if everything is working together. Here’s how to proceed:

•  Plug the entire drain system to the drain hole in the wall. Make sure to use nuts and screws if needed to secure everything well.
•  Then tighten everything up. Make sure nothing is wobbly or too rigid as it could cause breakage over time.
•  Proceed to fill the sinks with water. Then let the water out through the drain and check for any type of leakage.
•  There shouldn’t be any problem if you installed everything well. You can finish by connecting the disposal unit to the electric outlet or hardwired system.

Check that the machine works well, and then you’ll be ready to start using it with your double-sink setup.

Final Words

As you see, it is a little complicated to do, but if you follow our advice and every single step to the letter, then you shouldn’t have any problem.
Remember to always have all the tools and items necessary before starting if you want to make this possible. Otherwise, check again and again until you do.
Do this, and installing a garbage disposal unit into your double sink won’t be a problem in the slightest.

Last update on 2024-03-19 / Affiliate links / Images from Amazon Product Advertising API. WaterFilterly is user-supported. We might receive a commission on any purchase you make through clicking links on this page.