Rebar

Steel reinforcing bars embedded in concrete or masonry to increase tensile strength and prevent cracking under load. In masonry construction, rebar is placed vertically in hollow concrete blocks (CMUs) or horizontally in bond beams, then grouted solid to create a reinforced structural system. Ontario building codes require rebar in load-bearing walls, retaining walls, and foundations to resist lateral forces from soil pressure, wind, and seismic activity. Common sizes include #4 (1/2 inch) and #5 (5/8 inch) bars, with spacing determined by engineering calculations based on expected loads.