What weakness do gusset plates (aka gang nails) present in lightweight truss construction?

The correct answer indicates that gusset plates, also known as gang nails, penetrate the wood only a limited depth of 1/4 of an inch. This shallow penetration can create a significant structural weakness in lightweight truss construction. Since the connection between the truss members relies on this limited engagement with the wood, it may not provide the depth of stability and strength expected in traditional construction methods, where connections are typically designed to engage more deeply with the material.

In scenarios such as fire exposure, the integrity of these shallow connections can be compromised more quickly than deeper connections found in heavier timber or steel constructions. This can lead to rapid structural failure, as the truss cannot adequately transfer loads or maintain its shape under stress, especially in high-temperature conditions common during a fire. Therefore, understanding this limitation is essential for fire service personnel when assessing structural integrity in fire situations.