An aisle containment system is disclosed. The aisle containment system includes a frame defined by wall beams, header frames, and a plurality of posts secured to the wall beams and header frames. The header frames extend the width of the frame and the wall beams extend the length of the frame. A plurality of blanking panels extend from the floor to one of the wall beams. The plurality of blanking panels have a top, a bottom, a first side and a second side. Vertical stiffeners are positioned along at least one of the first side and the second side of each blanking panel. The blanking panels overlap adjacent blanking panels along the length of the frame. The blanking panels are laterally adjusted to fill openings in the aisle containment system.