What aspect of bricklayers' technique increases the strength of a brick wall?

Staggered bonds are a crucial aspect of bricklaying technique that significantly enhance the strength and stability of a brick wall. When bricks are placed in a staggered pattern, also known as a running bond, each brick overlaps the adjacent bricks rather than aligning directly above one another. This method distributes the weight of the wall more evenly and reduces the likelihood of vertical cracks forming. The staggered arrangement provides additional interlocking between the bricks, allowing for better load distribution and structural integrity, which ultimately strengthens the wall.

Uniform spacing, vertical placement, and selection of mortar type are also important factors in bricklaying, but they do not directly contribute to the enhanced structural strength in the same way staggered bonds do. While uniform spacing ensures aesthetic appeal and can help with even mortar application, and the choice of mortar type can influence adhesion and weather resistance, it is the arrangement of the bricks itself that is most critical to the wall's overall strength and stability.