Function

Regulations stipulate that all shower drains, as well as all fixtures applied to the common plumbing system of a building, need P-traps. A P-trap is the curved pipe seen under a bathroom or kitchen sink directing waste water back into the wall. This same piping is used under the shower drain.

Significance

P-traps are utilized to provide a barrier for sewage fumes and small organisms to enter the building. They are also useful in case of accidental item drops down the drain. The P-trap is a way to divide the fixture from the external plumbing, allowing rescue of the item before it is washed away.

Interesting Fact

The barrier within the P-trap to prevent fumes is trapped water from using the faucet or shower.