What is the primary requirement for secondary drains?

The primary requirement for secondary drains is to discharge above grade. This is essential because secondary drains, often referred to as emergency or overflow drains, are designed to manage excess water that could arise from various sources, such as rainwater or system failures. By discharging above grade, they prevent water from pooling around foundations or entering areas where it could cause damage or create flooding situations. This positioning helps ensure effective drainage and minimizes the risks associated with excess water, providing an extra layer of protection for the plumbing system and the structure itself. When thoughtfully designed to discharge above grade, secondary drains enhance the overall efficacy and reliability of the drainage system.