A rollup door assembly including a corrugated flexible sheet closure member secured to a rotatable drum for rolling the closure member onto and off of the drum for opening and closing the door. Opposed channel shaped guide tracks are securable to a wall adjacent an opening to be closed by the door and include elongated wind lock members disposed therein. Elongated polymer rub strips are secured to reentrant end portions of the channel shaped guide tracks for engagement with lateral side edges of the door closure member. Somewhat hook shaped wind lock members are secured to the closure member at the side edges, respectively for engagement with the wind lock members in the guide tracks. Drum support brackets include laterally extending tab members insertable through openings in web portions of the guide tracks for rapid assembly of the drum support brackets to the guide tracks. Closure member bottom edge stop members are mounted on the guide tracks adjacent the upper end thereof and are also provided with spaced apart tab members which extend through openings formed in flanges of the guide tracks for rapidly securing the stop members to the guide tracks.