Do Garbage Disposals Need An Air Gap?

Garbage disposals are the needed friend to bury those unwelcome scraps from view. However, there are important needs to consider when it comes to our disposal friends. This includes the necessary space to properly dispose of the scraps that we give them.

Garbage disposals need an air gap to prevent any possible cross-connections and contaminations that can occur by waste or discharged water. This is especially necessary to prevent cross-contamination with any connected dishwasher.

Although this friendly air gap may be helpful to your garbage disposal in properly disposing of waste without any extra issues, there are issues that can occur if the air gap is not functioning correctly, especially if the air gap is not in the right position.

The general purpose of an air gap

So what is the general purpose of an air gap? And what difference can it possibly make in any appliance?

An air gap is designed to prevent cross-contamination and build-up. It is most commonly applied to the facet of a sink, with a gap strategically placed to prevent build-up behind the fixture.

One specific air gap example is the gap between the facet and the drain underneath it. Thanks to this gap, the dirty water can never reach the facet. This also prevents the contamination that would come to the tip of the facet itself were the gap to not exist.

Warning: Without a proper gap in certain appliances, it could ruin the water that is coming through to the appliance itself. Be it a dishwasher, sink, or garbage disposal system.

For your information: There are places that allow you to have a direct connection between your dishwasher and your garbage disposal. However, such ideas would require a more complicated method known as “The High Loop Method”.

Warning: “The High Loop Method” is not nearly as safe as the air gap and many other risks and issues may still occur. In order to avoid these issues altogether, it is far better to continue by having the air gap to begin with.

(Source: Under Sink Air Gap Installation | Hunker)

(Source: Why Do You Need An Air Gap? We’ve Got Answers (

The proper placement of the air gap

The air gap should be placed where it will be able to intervene between any interconnecting clean or dirty water.

The effect of an air gap in disposal systems

As described above, the air gap is a necessary friend that will prevent your dishwasher from going to war over waste contamination with your disposal system. The air gap acts as a median or parental guide to intervene and keep the two from clashing together.

This brings about the desired effect of peace between the two, providing that the air gap does its job properly. In this case, the two should never meet.

Warning: Cross-contamination can cause damage and or, thick build-up that is far more difficult to deal with. It is better to install the air gap to begin with, than to risk cross-contamination and thick waste which will clog and or damage your disposal pipes.

As described above, with the general purpose of the air gap to a faucet and sink, the air gap will separate the two hoses, as it would with two dogs that would potentially war over their respective territories, leaving damage behind for us to clean up.

(Source: Do I need an air gap if I have a garbage disposal? (

Dishwashing waste versus air gap

If there is not a proper parental guide or gap between both the dishwasher pipe and the garbage disposal, then dirty water from the dishwasher will flood the disposal, decreasing the capability of the disposal to drain the sink and clear any scraps or debris that it contains.

This could cause many unwelcome issues or damage not only to your disposal but to the septic tank and the pipes as well. This damage would require extra cleaning and repairs that wouldn’t be necessary otherwise.

Tip: If something does happen to any of these items in your home, then please call a professional to repair or clean the items that have been affected by the rising sludge.

(Source: Do I need an air gap if I have a garbage disposal? (

Required by a plumbing code

Having an air gap will prevent unnecessary mishaps, and bring life back into our disposal system. As many of us know, there tends to be build-up that prevents your sink from draining properly at times.

These sorts of issues usually occur when your disposal is cross-contaminating, or the drain below is built up with thick sludge and debris from the previously discarded scraps.

Most of these requirements or plumbing codes demand a minimum of a two-inch air gap. This gap normally applies to a pipe that is two inches in diameter. The gap is usually double the diameter of the pipe.

For example;

Two inch pipe -> four inch air gap
three inch pipe -> six inch air gap

And so on. adjust the gap as needed. Or even consider seeking professional help so as to provide the most exact help necessary for your precious garbage disposal system.

(Source: Why Do You Need An Air Gap? We’ve Got Answers (

Air gap assembly in connection to garbage disposals

There are typically two air gap houses that interconnect in an upside-down ‘Y’ formation with other piping from under the sink. If you are concerned about whether or not your garbage disposal will accommodate the air gap, then you should know that every garbage disposal is designed to have this accommodation.

Tip: Be sure that the pipes are coated in a faux-chrome finish, and that a cap is placed over the top of the air gap.

(source: Under Sink Air Gap Installation | Hunker)

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