Sink Trap
Definition and meaning of Sink Trap in real estate.
Sink trap is a curved, water-filled section of pipe located directly beneath a plumbing fixture that prevents sewer gases from entering the home.
In more detail
Commonly shaped like the letter P, this pipe holds a small, permanent pool of water that creates a physical seal against gases rising from the drainage system. Without this trap, hazardous and foul-smelling gases would escape into the kitchen or bathroom. Home inspectors evaluate sink traps to ensure they are properly shaped, made of approved materials, and free of leaks or corrosion.
Homebuyers should check for slow drains or sewer smells, which can indicate a clogged, dry, or improperly vented trap.
Key facts
| Category | Property Types & Construction |
|---|---|
| Also known as | P-trap |
| Common material | PVC plastic or brass |
| Primary purpose | Blocking sewer gases |
While inspecting a kitchen sink, a home inspector notes that the PVC P-trap is dry because the house has been vacant for months, allowing sewer odors to seep into the room.
Frequently asked questions
Why does my sink trap keep losing its water?
A sink trap can lose water through evaporation if unused for a long time, or through siphoning if the plumbing system lacks proper venting.
Are S-traps still allowed in modern residential construction?
No, modern building codes generally ban S-traps in new construction because they are prone to siphoning dry, and they must be replaced with P-traps.