What is the strongest overlap of masonry units when constructing a wall?

The strongest overlap of masonry units when constructing a wall is a one-half lap. This technique involves aligning the masonry units in such a way that one half of the length of each unit overlaps with the adjacent unit. This overlap significantly enhances the structural integrity and stability of the wall, as it provides a more uniform distribution of loads across the wall, reducing the likelihood of cracking or failure.

When the units overlap by one-half, they also create a better bond between the units, contributing to improved resistance against lateral forces, such as wind or seismic activity. This overlap is particularly important in ensuring that the wall remains strong and durable over time, effectively preventing issues that might arise from suboptimal bonding or alignment.

In contrast, a one-third lap or quarter lap does not provide as much lateral support and can lead to weaker joints in the wall construction. A full lap, while it may sound strong, is actually not practical for most masonry applications due to the need for proper spacing, mortar application, and the overall design of the wall. Therefore, one-half lap is recognized as the most effective and reliable method for achieving a strong masonry wall.