Suction Roof Drain

The suction flat roof drain is deployed on a flat roof between a water accumulating depression on the roof and the edge of the roof. The flat roof drain includes an intake tube section with an open end disposed in the flat roof depression and a raised tube element spaced apart from the open end. The intake tube section is attached, at an end opposite the open end, to a water collector which collects rainfall. The water collector has an open accumulation port, a water collection body part and a one-way flow valve. The one-way flow valve is interposed between the water collection body part and an intake suction port and an output port. The output port of the water collector is attached to one end of an output tube section. The other end of the output tube section hangs over the edge of the roof (or into another drain element). The second or other end of the output tube section operates as a weight activated fluid output which permits water to drain therefrom when water is present at the second end. In operation, rainfall collected in the water collector and causes the one-way flow valve to open which then causes the water in the water collection body to drain through the output tube section off the roof thereby creating a suction in the intake tube section which pulls water from the flat roof depression.