What percentage of wall surface must solid headers comprise in multiple wythe masonry walls?

In multiple wythe masonry walls, solid headers play a critical role in ensuring structural integrity and stability. The requirement that solid headers must comprise a minimum percentage of the wall surface ensures that there is enough material to effectively distribute loads and provide reinforcement within the wall assembly.

The correct percentage of 4% reflects the industry standards for load-bearing criteria in construction. This specification helps prevent issues such as cracking or failing at the interfaces of the masonry units. Adequately spaced and sized headers contribute to the overall strength of the wall system by creating a more interlocked structure, which is particularly important in masonry construction where weight distribution is crucial.

Other percentages offered in the options don't align with these established guidelines, highlighting the importance of adhering to building codes and best practices in ensuring both safety and performance of masonry construction. Thus, the correct understanding of the percentage of solid headers is vital for anyone involved in the design or construction of multiple wythe masonry walls.