The Real Deal on Covering Your Sink Before Vacation: The Truth About the "Upside-Down Glass" Hack (And How to Actually Protect Your Home)
Nora PatelThe idea behind this hack is entirely legitimate. The P-trap, which is the curved, U-shaped pipe located beneath your sink, tub, and floor drain, does hold water as a protective barrier against sewer gases and insects entering your home. However, the method shown in the viral photo—using paper and a glass—is not a reliable way to protect your home.
Let’s gently unpack the real plumbing issue behind this idea, why the viral hack falls short, and the simple, old-fashioned tricks that will actually keep your home smelling fresh and peaceful while you’re away.
🚰 The Plumbing Magic: Understanding the P-Trap
Every sink, tub, and floor drain in your home contains a small piece of plumbing magic referred to as a P-trap. Most people have heard of the P-trap, but may not know that the curve of the pipe wasn’t designed to catch lost jewelry or hairballs, but rather to hold water on purpose.
The water within the P-trap creates a physical barrier between your home and the large sewer system outside. This barrier is commonly known as the “water seal.” It provides a vital level of protection by blocking unpleasant sewer gases, methane, and odors from floating up the pipes and into your living spaces. It also stops small insects (like drain flies) from using the pipes as a highway into your bathroom.
However, if you leave a drain unused for a sufficient amount of time, that water will eventually evaporate. When the water disappears, the protective barrier is eliminated. At this point, you may begin to notice a foul odor upon returning home, or worse yet, unwanted critters may begin to enter.
Therefore, the reasoning behind the viral hack is valid: if you plan to leave your home for a significant period of time, you absolutely do not want your P-traps to dry out.