A P-trap works by holding water in its curved section, creating a seal that blocks sewer gases. When a drain isn’t used often — such as a basement floor drain, guest bathroom sink, or laundry drain — that water can slowly evaporate, allowing odors to escape.
The simplest solution is regular use. Running water for 10–15 seconds every few weeks is usually enough to keep the trap full. For drains that are rarely used, some homeowners add a small amount of mineral oil after running water, which slows evaporation without affecting drainage.
If sewer smells keep returning even after adding water, there may be a deeper issue like a leaking trap, poor venting, or an improperly installed drain. These problems won’t resolve on their own and often worsen over time.
Done! can identify whether a drying P-trap is the real issue or a symptom of something bigger. For dependable plumbers for Denver, our team is ready to help keep your drains sealed, odor-free, and working properly.
