What is a requirement for shower pans in plumbing installations?

For shower pans in plumbing installations, a key requirement is that they must be turned up on all sides above the threshold. This design is essential for preventing water from leaking out of the shower area, thereby protecting the surrounding structure from water damage. The upward turn creates a barrier that ensures that any water that splashes outside of the shower doesn't escape beyond the designated area.

This requirement also aids in ensuring that the drain system functions effectively, as it channelizes the water towards the drain and keeps the area well-contained. Utilizing this configuration promotes durability, maintains hygiene, and supports compliance with plumbing codes which are established for safety and functionality in wet environments like showers.

Other options such as requiring the shower pan to be flat on all sides or removable pertain to different design considerations but do not fulfill the critical need for water containment and safety. Moreover, while material choices may vary, restricting the construction of shower pans solely to plastic materials is overly prescriptive and not aligned with industry standards which allow for various materials as long as they meet the functional requirements.