What is the name of the interior drainage pipe that carries storm water from roof drain systems?

The interior drainage pipe that carries storm water from roof drain systems is known as a conductor. This terminology is used within plumbing to refer specifically to pipes that transport collected water from the roof to the drainage system, whether it be a storm sewer or another designated outlet. Conductors are designed to handle large volumes of water efficiently during heavy rainfall, ensuring that the water is directed away from the building to prevent water damage or flooding.

Downspouts are typically the exterior version of this system, conveying water from gutters down to the ground, while drainage channels refer to surface drainage systems, not pipes. Sewer lines deal with wastewater and are not intended for storm water. The correct identification of conduits for storm water helps in proper building design and maintenance, ensuring effective water management and prevention of structural damage.