Oh, my dear friend, I see this travel tip circulating all the time, and I always have to smile. The idea of covering your kitchen sink before leaving for a trip sounds a little like an old wives’ tale, but there’s actually a practical reason behind it. At 73, living here in my cozy farmhouse, I’ve learned that the best vacations are the ones where you can truly relax without worrying about what might be happening at home. So, with a cup of chamomile tea beside me, I decided to look into the plumbing science behind this popular travel trick.
The secret is the small but important P-trap beneath your sink. That curved section of pipe is designed to hold water, creating a seal that helps keep sewer gases and unpleasant odors from coming back through the drain. When you leave home for several weeks, however, that water can slowly evaporate. Once the trap dries out, there is no longer much of a barrier between your home and the smells from the plumbing system. Covering the drain with plastic wrap, a wet cloth, or a drain stopper can help slow evaporation by limiting airflow over the water. Some people also use a small amount of mineral oil to create a thin layer on the water and reduce evaporation.
And don’t forget that the kitchen sink isn’t the only drain that can dry out. Bathroom sinks, especially those in guest bathrooms, can be affected, as can bathtubs, showers, and floor drains that are rarely used. For floor drains, adding some water periodically can help keep the trap filled. Before leaving for a long trip, it’s worth taking a quick look around the house and making sure infrequently used drains have enough water in their traps. A few seconds of preparation can prevent an unpleasant surprise when you return.
When you come home, simply remove whatever you used to cover the drain and run the water for a little while to refresh the trap. That’s really all there is to it. It may seem like a tiny household trick, but avoiding stale sewer odors after a relaxing vacation is certainly worth the extra minute before you leave. Sometimes the simplest precautions are the ones that give you the most peace of mind.
