Trap
Definition and meaning of Trap in real estate.
A trap is a curved section of plumbing pipe positioned beneath a fixture, such as a sink or toilet, designed to hold a standing pool of water. This water barrier forms a tight seal that prevents toxic and foul-smelling sewer gases from entering the living space.
In more detail
Most residential fixtures utilize a U-shaped or P-shaped trap, which is required by modern building codes to ensure sanitary living conditions. The water in the trap is replenished every time the fixture is used, ensuring the seal remains intact. If a fixture is left unused for months, the water in the trap can evaporate, allowing sewer odors to leak into the home.
Real estate investors and inspectors look for proper traps during home inspections, as improper installations or obsolete S-traps can lead to siphoning, sewer gas leaks, and plumbing code violations.
Key facts
| Category | Property Types & Construction |
|---|---|
| Common Type | P-trap |
| Required By | Building codes |
| Critical Function | Blocking sewer gases |
An inspector examines the plumbing under a kitchen sink and confirms a P-trap is installed correctly to prevent sewer smells from entering the kitchen.
Frequently asked questions
What happens if a sink trap dries out?
When a trap dries out due to lack of use, the water seal evaporates, allowing sewer gases to rise up through the drain and create a foul smell in the room. Running water for a few seconds will quickly refill the trap and restore the seal.
Why are S-traps no longer allowed in modern construction?
S-traps are banned by modern plumbing codes because the design is prone to siphoning, which can pull the water out of the trap and break the protective seal.