Abstract: A dual closure system for overhead doors in a structure having a floor, a vertical wall, a ceiling structure, and a rectangular door opening in the wall which extends from the floor upwardly in a direction towards the ceiling has a pair of spaced tracks with a vertical segment extending upwardly from the floor adjacent vertical sides of the door opening, and terminating through curved track segments into a pair of vertically horizontal upper and lower track portions. The curved track segments both have lower ends arcuately merging into alignment with an upper end of the vertical segments of tracks. The upper ends of the curved track segments terminate in vertically spaced horizontal track portions. First and second foldable doors which have sets of rollers on their side edges are movably mounted one each in the horizontal portions of the track so that each door can be individually moved into a vertical position in the vertical segment of the tracks.