Are stack-bonded walls more likely to crack than conventional bond patterns?
Yes. Because the head joints line up in a stack-bond wall, vertical cracking is more likely to occur. For this reason, stack-bonded walls should be built with reinforcing in the bed joints. The Brick Institute of America Technical Notes 30, "Bonds and Patterns in Brickwork," recommends reinforcing large areas of stack-bonded masonry and whenever this pattern is used in load-bearing walls. ACI 530-88/ASCE 5-88 requires that stack-bonded walls be reinforced. Reinforcing is to be placed no farther than 48 inches apart. The cross-sectional area of the bars is to be 0.07% the cross-sectional area of the wall.