My wife and I just bought a new house and she's partial to the composite sinks. However, the sink we purchased (and installed) has only one hole for the faucet fixture and not for the airgap. We also have a garbage disposal (from previous sink) and dishwasher. I ended up loosely angling the hoses towards the upper end of the cabinet so the chrome cover was closest to the counter top.

We tried to run dishes in the dishwasher and water naturally filled into the sink. We stopped the cycle and haven't used the dishwasher in the meantime, but what should I be doing? Do I, or can I, position the air gap under the countertop as I have? Should I cut a hole in the sink? (Unhappy wife scenario) Should I return the sink with one that has the appropriate holes?

Here's a rough image that I had on my phone already of the situation. I can get some better pictures tonight if necessary:

Rats nest under the sink


I goofed up, seems the stickers indicating where the punch out holes were had fallen off. So, I was able to punch the air gap hole out of the composite sink and file it down.

Before I punched the hole out, I was thinking of connecting the dishwasher directly with the disposal using a "high loop". However, apparently "high loops" are not to legal code in the state of Washington.


2 Answers 2


I would suggest drilling a hole through the composite sink using the proper sized hole saw.


I don't know if this is up to code, but can't you get some other type of backflow prevention valve instead of the air gap?

I've never installed a dishwasher, but I've never had one with an above the counter air gap either. I assume they must have some other type of backflow check valve.

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