Overflow Roof Drain - Water Dam Type with Adjustable Extension

The combined flashing clamp and 2" (50) solid water dam of this adjustable roof drain spins around a threaded extension to conform to the thickness of flat roofs of any construction. It is engineered specifically for roofs where a rooftop pool of water insulates the building's interior or on conventional roofs where an emergency overflow is needed. This 15-1/ 4" (390) Duco coated cast iron drain adjusts on-site during installation to roofs between 1-1/ 4" (100) (32) and 4" (100) thick with up 2-3/ 4" (100) of insulation. A polyethylene dome strainer protects drainage lines from debris.