The guidelines for proper spacing and lapping of steel rebars in concrete structures vary depending on the specific design and structural requirements. However, some general recommendations exist. The rebars should be adequately spaced to ensure proper concrete cover, allowing for corrosion protection and sufficient bond strength. Typically, the minimum spacing between parallel rebars is around 1.5 times the diameter of the larger bar or 25 mm (1 inch), whichever is greater. Lapping, or overlapping, of rebars is necessary to create a continuous load path. The length of the overlap depends on the design and the type of rebar connection being used. It is important to follow the specifications provided by structural engineers and adhere to local building codes to ensure the proper spacing and lapping of rebars in concrete structures.
