Abstract: The invention is a sliding door assembly for an H-frame rack system. The H-frame rack system includes a plurality of substantially vertical posts, and a plurality of substantially horizontal beams connected to these vertical posts. Merchandise-carrying shelves are supported by the horizontal beams. The sliding door assembly includes at least one sliding door. Rollers are secured to the sliding door or doors for facilitating lateral movement of the sliding doors along the H-frame rack system. Channels secured to at least one of the horizontal beams are positioned above the sliding doors. The rollers are guided within these channels.