The minimum rebar spacing for slabs depends on bar diameter, concrete aggregate size, and the layer arrangement. According to ACI 318, clear spacing should not be less than the greatest of: 25 mm, the bar diameter, or 1.33 times the maximum aggregate size. Similarly, Eurocode 2 requires spacing of at least the greater of: 20 mm, the bar diameter, or the maximum aggregate size plus 5 mm. These values apply to both the main and distribution reinforcement layers. To maintain code-compliant spacing, ensure proper rebar layout in both directions and between layers. For example, use consistent bar spacing based on slab thickness and bar size. Maintain clear horizontal gaps and vertical distance between layers to allow concrete to flow properly. In addition, be sure to avoid bar congestion near slab edges and openings. Correct rebar spacing allows full concrete compaction, minimizes voids, and improves structural performance. It also helps prevent cracking and ensures load transfer across the slab. Therefore, following minimum spacing rules is essential for durability, serviceability, and compliance with structural codes.