Which is a critical consideration when installing a P-trap?

A critical consideration when installing a P-trap is the distance from the fixture outlet. The P-trap is designed to retain a certain amount of water, creating a barrier that prevents sewer gases from entering the living space. This means that the trap must be positioned at the appropriate vertical height relative to the fixture to ensure proper drainage and function. If the trap is too far from the fixture outlet, it may lead to issues such as slow drainage or potential clogs, as the water may not flow correctly into the trap. This distance is essential for maintaining the hydraulic seal and ensuring that gravity helps facilitate drainage effectively.

Other options, while relevant in certain contexts, do not have the same direct critical impact on the function of the P-trap as the distance from the fixture outlet.