FD-4080GX series of dome type large sump roof drains consist of cast iron body with vertical outlet, a membrane clamp with integral gravel stop and stainless steel gravel guard extension.
Used in IRMA flat roof construction (inverted roof membrane assembly). The dome provides maximum free area for quick drainage of rain water through the large sump body and protects the drain and connected piping from the intrusion of debris. The Flashing (V-Shape) clamp holds flashing and roofing materials to the drain body without puncturing. The stainless steel extension gravel stop at height specified is supplied to retain the crushed gravel used in IRMA flat roof construction.