What are internal drains?

• A. Drains that remove water through piping but are vulnerable to blockage
• B. Exterior scuppers
• C. Roof vents
• D. External gutters

Answer: (A)

Internal drains are drainage paths that carry collected roof water through piping located inside the building or roof structure, delivering it to a discharge point via a pipe network rather than venting water to the outside at the edge. This arrangement means the water is moved through enclosed conduits, which helps keep the surface cleaner and provides a neater appearance, but it also makes the system more prone to blockages from debris, sediment, ice, or fouling inside the pipes, traps, and cleanouts. Therefore, reliable performance depends on proper design features like accessible cleanouts, adequate slope, and secure connections to the building drainage system. Exterior options such as scuppers, or gutters along the edge, discharge water outside the roof area and are not internal drains. Roof vents are for ventilation and do not function as drains.