How to Plumb A Single Bowl Kitchen Sink With Disposal

The kitchen sink is used multiple times a day in each of our homes. If you frequently wash dishes and let bits of food fall into the drain and you don’t have a disposal, the drain pipes can quickly become blocked. This is why many homes decide to connect a disposal to their sink.

If you’re wondering how to plumb a single bowl sink with disposal yourself, this is the guide for you. The process will take an hour or two but is very straightforward. Plumbing the disposal yourself can save $80 – $200 in installation costs. 

Can You Hook A Garbage Disposal Up To A Single Bowl Kitchen Sink? 

Yes, connecting a disposal to one of these sinks is a simple task. It is quicker and easier than connecting a disposal to a double sink. As long as there is enough space underneath the sink to fit the disposal and the pipes then you shouldn’t have a problem with the installation. With that said, not all single bowl kitchen sinks are compatible for a disposal and certain sinks may require additional pieces such as a longer flange for the system to fit. 

While most garbage disposals fit with most sinks, they are not a universal fit. With this in mind, it is always worth taking the time to ensure you buy a compatible model. The motor size you choose is also going to impact the price of the disposal unit so getting a disposal that is appropriate for your use and the available space could even save you money. 

6 Benefits of Installing A Disposal With A Single Bowl Sink 

Many kitchens utilize disposal systems because this simple appliance comes with several important benefits:

Prevents the Drain from Clogging 

One of the main benefits is that the disposal system helps protect the drain. Rather than food particles going into the pipes where they will build up and cause blockages, the food will be broken up by the disposal. In short, having a disposal installed will help to extend the lifespan of the plumbing in your kitchen. 

Fewer Repairs and Replacements Needed

If your kitchen sink and the connected drainage pipes are becoming clogged and are being put under a lot of strain they are more prone to needing to be repaired or replaced. When using a disposal, it helps to protect the pipes which means you won’t be calling the neighbourhood plumber for constant maintenance and repairs on your kitchen pipes.  

Speeds Up the Washing Up Process

No one likes washing up and having a disposal means you can deal with food waste and do the dishes quickly and easier. It is a simple way of streamlining the process so you can spend more time enjoying the food than washing up the dishes. 

Prevents Food Waste from Going into Landfill

When you have a disposal, the food waste no longer needs to go into the trash where it will eventually end up in a landfill. There is a huge amount of food waste that ends up in landfills each year and this emits masses of methane. Using a disposal means you are not contributing to this. This makes the disposal a more environmentally friendly way of handling waste. It can also make you more aware of the food that is being thrown away which can in turn help to reduce food waste. 

Reduces the Amount of Food Waste Left In Garbage Bags 

As there will be less food waste for you to throw out, this means it will reduce the likelihood of wildlife digging through the trash. With animals not searching through your garbage for food scraps, it helps to keep your home and yard clean. It also means the garbage bags won’t smell like old food either. 

Low Cost 

If you’re worried that the benefits we have listed will come at the cost of a higher electricity bill, don’t worry. The disposal is a highly efficient appliance that uses very little electricity. Using a disposal will barely impact the amount of electricity being used in your home. There will not be a sudden increase in your electricity use. 

Overall Cost Estimation 

How much it costs to install a disposal depends on a couple of key factors. Installing the disposal can cost just as much as buying the unit. If you install the disposal yourself it won’t cost much, as you’ll be saving on labor costs. 

Disposal Unit 

The amount it costs to buy a disposal unit is going to depend on the make and model chosen. Disposals cost between $85 – $200 on average. When choosing the disposal unit, make sure it is not only compatible with your sink but is providing the amount of power that is needed. There is no point getting a large, high power garbage disposal just for the sake of it as it will not only cost you more to buy but you may struggle to install it under your sink. Particularly if the space under the sink is tight. 

Labor Costs

If you are getting the disposal unit installed by someone else you can expect to pay between $80 – $200 for the installation cost. The amount you pay will really depend on the individual hired, their rate and how long the job takes. You can avoid labor costs by installing the disposal yourself. 

Overall Cost 

With these two key costs considered, the overall cost of purchasing and installing a garbage disposal is between $160 – $400 with around $250 being the average. This isn’t bad but it’s easy to cut this cost in half by handling the installation yourself. 

How To Install Garbage Disposal In A Single Sink: 15 Easy Steps 

Installing the garbage disposal yourself will take a couple of hours as long as you have the right tools for the job. We have outlined the most common installation process but it is always important to check the manufacturer’s installation instructions too.  

Tools Needed 

  • Disposal Unit 
  • Washing up bucket
  • Nuts 
  • Electrical tester (non contact)
  • Pliers (slip-joint)
  • A rag
  • Putty knife (plastic)
  • Plumber’s putty 
  • Hammer
  • Screwdriver 
  • Utility Knife 
  • Wire stripper

Step 1. Make Space in the Cupboard Under the Sink

Before you get started, take out anything that is in the cupboard under the sink. You need the cupboard to be empty so you have enough space to position the disposal and pipes as necessary. It is also worth placing a washing up bucket or something similar under the pipes so that when you disconnect them any water can be caught and disposed of. 

Step 2. Switch the Electricity Off 

Next, the power needs to be disconnected at the breaker switch so the electricity is off to the kitchen. This is an important step for your safety as it is necessary to wire in the disposal during the installation. Once the breakers are off, use the tester to test the wires beneath the sink to ensure the electricity is not on. 

Step 3. Detach the P-trap and Extension Pipe 

Locate the couplers that are holding the extension pipe and the P-trap to the underside of the sink. Use the pliers to remove the couplers and remove these drain pieces. There might be a small amount of water in these pipes so try to direct any water into the bucket to reduce how much cleaning you’ll need to do after the installation. 

Step 4. Plug the Drain With the Rag 

As you have removed part of the drain, place a piece of cloth into the drain pipe to stop any unpleasant odours coming through the line. Don’t worry, this is just a temporary measure while you install the disposal. The last thing you want is drain odours in your face while you work. 

Step 5. Loosen the Coupling 

Next, take the pliers and use them to loosen the nut located beneath the coupling. Once this nut is loose, you will be able to move the coupling. The flange that is attached to the sink’s underside will come away as the coupling is pushed. 

Step 6. Scrape Away Old Putty 

It’s likely there is going to be old putty there so use the knife to gently remove the putty. This is a quick and simple job but it is important so don’t skip it. If you don’t clean the old putty then you may struggle to get the sink pieces securely back together. 

Step 7. Put Plumbers Putty Onto the Disposal

Now you can put new plumbers putty along the sink flange of the disposal. You don’t need to use too much putty as a little goes a long way. 

Step 8. Install the Disposal 

With the putty now in position, move the disposal flange so it goes into the hole of the sink. To protect the seal, position a backup ring along with a gasket on the open sleeve of the flange (underneath the sink). The disposal should now be in position and we will connect the pipes once we have wired the disposal up. Now you can remove any excess putty you can see. 

Step 9. Knock Out the Dishwasher Blocks (if Connecting a Dishwasher)

Before we continue, if you are going to be connecting a dishwasher to the disposal you can knock away the dishwasher plugs. This is easiest to do using a screwdriver and a hammer. This is only needed if you will be connecting the dishwasher immediately. If you aren’t connecting a dishwasher, skip this step. 

Step 10. Wire the Disposal In

With the disposal in position, the next thing to do is wire it in. Take the cover from the wiring compartment of the disposal and insert around 6 inches of the cabling from the switch in the wall, securing it into place with a clamp. Tighten the clamp with the screwdriver. 

Step 11. Strip the Wires

Gently unsheathe the cable using the utility knife. Next, take the wire stripper and remove 1/2  inch of the insulation. Stripping is only required on the black wires and the white wires.  

Step 12. Connect the Wires

In this step you need to connect the wires, ensuring you properly coordinate the colours. Once you have attached the wires to their necessary counterparts, put the wires away neatly and close the wiring box. 

Step 13. Connect the Disposal Discharge Tube

Now you need to put a mounting ring under the disposal system and turn it so the outlet and the pipe of the drain are facing each other. Connect the disposal discharge pipe to the insight of the disposal outlet. Keep it in position by using the pliers to secure the coupler. 

Step 14. Connect the Drainage Pipes

Remove the piece of cloth from the drain pipe. After that, put the extension pipe and P-trap back into position. Use the pliers to secure the couplers. Now is the time to connect up your dishwasher if needed. 

Step 15. Test

Finally, you simply need to turn the power on and run water through the sink. Switch the garbage disposal unit on and see if it works. Most importantly, there should be no leaks or strange sounds. 

Related Queries 

Below we’ve answered common questions about installing garbage disposals. 

Do all garbage disposals fit all sinks? 

No, garbage disposals are not a universal fit. However, most garbage disposals will fit most sinks as long as there is enough space under the sink for it. Always check the disposal attachments to ensure it will fit with your sink.

Do you need a special sink for a garbage disposal?

No, you don’t need a special sink as garbage disposals fit the majority of sinks. However, you need to make sure you choose the right size, shape and type of garbage disposal to suit your sink and the available space. 


Once you know how, plumbing a single bowl kitchen sink with a disposal is simple. Of course, you can get someone to install it for you but if you have the time and the tools it doesn’t take much to get the disposal up and running yourself. Above all, you can now enjoy all of the benefits and convenience of having a disposal.

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