At first glance, it looks strange—almost like a prank. An upside-down glass placed carefully over the kitchen sink drain, sitting on a sheet of paper as if it’s part of some unfinished experiment. But this setup, as odd as it seems, is almost always intentional, and surprisingly smart.
When people leave their homes for several days—especially apartments—little precautions can make a big difference. This simple sink arrangement is one of those low-key “if you know, you know” household tricks.
What’s Really Going On Here?
The upside-down glass is most commonly used as a barrier against sewer gases.
When a sink isn’t used for a while, the water in the P-trap (the curved pipe under the sink) can slowly evaporate. That water normally acts as a seal, blocking unpleasant sewer odors from coming back up through the drain. Once it dries out, those smells can creep into the apartment.
By placing a glass tightly over the drain, homeowners create a physical seal that prevents odors—and sometimes tiny insects—from entering the kitchen while they’re away.
Why the Paper?
The paper underneath isn’t random. It helps:
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Create a flatter surface so the glass seals better
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Prevent scratching the sink
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Make it obvious if the glass has moved (useful if someone else enters the apartment)
It’s practical and oddly thoughtful.
Other Reasons People Do This
While odor prevention is the main reason, there are a few bonus benefits:
