A roof vent comprising a one piece plastic body including a base wall having transversely spaced rows of integral vanes extending from one surface thereof. The vanes of adjacent rows are positioned such that the vanes define a sinuous path. Preferably, one of each of the rows has the wings extending at an acute angle to the axis of the wall and the other row of each set of rows has the wings extending at an oppositely directed acute axis to the longitudinal axis of the wall toward the wings of the one row. Thus air is vented through sinuous paths outwardly when the vent is positioned with the wings engaging the roof and the base wall spaced from the roof. Water and snow are prevented by the wings from entry beneath the vent into the building.