Abstract: A door structure including a retractable cover which has a rolling up section which is rotated so as to roll up and unroll a portion of the cover. Generally an upper edge of the cover portion is fixedly mounted to a roof portion of a door structure and the lower edge is free. The rolling up section is non-rotatably connected to the cover portion along a center line. Rotation of the rolling up section in one direction rolls up the cover portion and rotation in the other direction unrolls the cover portion. The rolling up section moves up and down respectively with the rolling up and unrolling of the cover portion. The rolling up section can be caused to rotate by toothed wheels at one end engaging with spaced rollers mounted on a framework associated with the cover. The cover portion extends, in a particular arrangement, between two end portions, although only one end portion may be provided.