For reinforced masonry to perform properly, you must place the steel reinforcement in the proper location, secure it accurately, and lap the bars sufficiently- all before placing the grout. The Uniform Building Code (UBC), the code followed in most of the western United States where reinforced masonry is routine, sets specific requirements for placing reinforcing steel. PROPER POSITIONING UBC sets tolerances for placing reinforcing steel. The spacing must between bars must be within plus or minus 2 inches. Before grouting, you must secure vertical steel reinforcing so it's held properly in position. The vertical steel also should be tied to the dowels projecting from the foundation. CLEARANCE AND COVER For stresses to be transferred properly between reinforcing steel and masonry, the steel must be surrounded by grout. At least 1/4 inch of fine grout or at least 1/2 inch of coarse grout is needed between the steel and the masonry unit. LAPPING BARS Building a reinforced masonry wall using a single continuous length of reinforcing steel isn't practical. Instead, the steel reinforcing bar is cut into manageable lengths. But for these shorter lengths to function as continuous reinforcement, they must be adequately connected. The usual method is to lap the bars a specified length. For bars in tension (in walls and beams), UBC requires that Grade 40 steel bars be lapped 40 bar diameters and Grade 60 steel bars be lapped 48 bar diameters.