A pan shall be provided for all floor drains when it is installed ________________.

The requirement for providing a pan for all floor drains installed on the second floor of a new office building is rooted in safety and building code practices. Floor drains, especially those located in spaces where water could accumulate, such as commercial settings, need to be properly managed to prevent potential water damage to the structure below.

When a floor drain is situated on an upper level, like the second floor of a new office building, any leaks or overflow would directly impact the floors beneath, making a pan a crucial component. A pan collects excess water that may escape from the drain, thereby protecting other areas of the structure from water damage, mold growth, and potential hazards associated with standing water.

In contrast, the other situations may not impose the same level of risk or concern for water damage, either due to different types of usage, building design, or specific regulations that might allow for exceptions in residential scenarios. Thus, emphasizing the need for such a precaution in commercial buildings, particularly on upper levels, ensures compliance with safety regulations and protects the integrity of the building structure.