What accessory must be installed on joists to prevent lateral movement when they frame into beams or girders?

The requirement for blocking on joists when they frame into beams or girders is critical for maintaining structural integrity. Blocking serves to provide lateral support between joists, preventing them from exhibiting movement or twisting that could compromise the overall stability of the floor system. This lateral stability is crucial, especially in structures that may experience dynamic loads such as those caused by occupancy or environmental factors.

Blocking also helps distribute loads evenly and ensures that the joists do not become dislodged or misaligned over time. As joists experience stress, the installed blocking will hold them in place, thus preserving the alignment of the framing. Without this accessory, the integrity of the framing can be compromised, leading potentially to structural failure or increased wear over time.

Nails and anchors are generally used for fastening or securing components, but they do not necessarily prevent lateral movement. The option indicating that no accessory is required ignores the need for structural support against lateral forces. Therefore, the installation of blocking is essential to ensure both safety and longevity in a building's performance.