IIBEC GCK and Registered Roof Consultant (RRC) Roofing Standards, Wind, and ASTM Fundamentals Practice Test

The main idea is to remove water and prevent ponding on the roof. A primary roof drain is the main outlet that collects rainwater at the lowest points and conveys it into the building’s drainage system. Keeping water from sitting on the roof is essential because ponding adds weight, stresses the roofing membrane, and increases the risk of leaks during storms. Venting air, supporting the structure, or moving roof waste aren’t the drain’s functions, so the primary purpose is clearly to manage water flow and prevent ponding.