Does draining a dishwasher to basement floor drain count as an air gap?

I’ve seen hundreds of washing machines and laundry tubs use a makeshift “stand pipe” to divert the water to a basement floor drain. But I’ve never seen a dishwasher use the same method. For some reason, this is a DLR (Doesn’t Look Right).

I would not think this would be a sanitary method of draining the dishwater. What would others recommend in this case? Maintenance Repair or a Defect and call in a plumber? There isn’t a Wye connector at the base of the piping, either, but maybe the Tee connector will slow down the flow enough that it won’t spill all over the floor.

If it doesn’t look right mention it. They drain sinks into floor drains like that in restaurants all the time but in the basement like that with food in the dishwasher waste I would just tell them to call out a plumber. Doesn’t look like a professional install anyways.

There is a very thin line between “gray water” and “waste water”.

Water from a clothes washer, a laundry tub, a bar sink (glasses only), a bathroom sink/shower, and a mop bucket drain are considered grey water.

Water from a dish washer and other sinks that would contain food particles, as well as the obvious other nasty drains containing feces are considered waste water.

At least that is how I was taught.

It’s a defect… write it up.


The DW drain must have a high loop that is at least 32 inches above the base of the unit.

Some areas such as Chicago require an air gap but not all do and in Chicago I doubt it is ever called out by anyone other than us (inspectors).

The drain situation is no different than having a slop sink drain there in my opinion so if you call those out then call this out as well.

Very often the basement drain goes to a sump which can either empty to the yard or the town sewage which is often against local codes.

I don’t call out slop sinks in basements with municipal sewer that drain to a floor drain. It is very common in our area that washers and/or utility sinks discharge to basement floor drains. These drains are usually 4 to 6 inches below the finished poured floor. I agree with Jeff’s comments. I did call it out in the finished report.

Check the owner’s manual and see what the manufacturer recommends. Recommend accordingly.

It wasn’t available

Use the serial number and find it online.

Yet another reason on site reports are inferior.

Or if allowed by AHJ.

:roll: I beg to differ.

I carry all reference material on my computer. I am always connected to the Internet and can download anything I might need - all while on site. How is that “inferior?”

Air-gaps are required in most CA jurisdictions. This is not an acceptable method (by CA standards) for draining of a dishwasher, even if it could be considered an “air gap.” CA requires the air gap to be above the flood level of the sink.

Just one quick question can the sewer main/line back up into the dishwasher as it is installed???:cool:

Master Plumber here- It’s a defect. Definately write it up. That hose is not “hard piped”- one kick and the hose is now discharging food particles all over the floor. The dishwasher discharge hose needs to be piped to a standpipe under the sink in a permanent fashion so that it cannot drain anywhere that it is not supposed to. The standpipe will have a built in air gap fitting. A hose running across the floor is not an “air gap”. An air gap needs to have physical separation from the drain to which it discharges straight down typically 2 times the pipe diameter or a minimum of 2"- i.e. 2 inch pipe need to discharge 4 inches above the drain it is discharging to.