What is the minimum lap requirement when floor joists frame across a wood girder?

The minimum lap requirement when floor joists frame across a wood girder is indeed 3 inches. This requirement is crucial for ensuring that the load from the floor joists is adequately transferred to the girder, providing structural stability and integrity. A 3-inch lap allows for proper bearing and support, minimizing the risk of failure due to inadequate load distribution. This dimension is also in alignment with standard building codes, which specify lap lengths to ensure the safety and performance of structural connections in wood construction. Properly meeting this requirement helps prevent issues such as sagging or excessive deflection in the floor system, contributing to the overall longevity and safety of the building structure.