ESPAC Precast Rib-Hordi roof system is a pre-fabricated structure for floors and roofs which is made from pre-cast Reinforced concrete ribs, PAC Hordi blocks, cross ribs and concrete topping for classic construction. The design is intended primarily for houses, low rise and civil building. The static calculation for Rib-Hordi roof system will determine the size of Ribs, concrete grade, reinforcement requirement and the concrete topping.