A closure system includes a plurality of closure panels adapted to be moved between deployed and stowed positions. All on a pair of carrier tracks on opposite side of a building opening. The actuator in the deployed position have abutting top and bottom edges and parallel side surface that span across the building opening. The actuators in the stowed position have abutting in inner and outer side surfaces in parallel top edges and parallel bottom edges. The top and bottom edges maintain their top and bottom orientation as their closure panels transition between the deployed an stowed positions.
