What is the allowable deviation from straightness for a 40' long primary truss member?

The allowable deviation from straightness for a 40' long primary truss member is specified to be 3/8". This measurement is important in maintaining the structural integrity and performance of the truss. When trusses are fabricated and installed, they need to follow precise geometric specifications to ensure that loads are distributed evenly and that the structure behaves as intended under various design conditions.

Deviations beyond 3/8" may lead to uneven load distribution, increased stress on certain members, and potential failure points within the structure. Maintaining this level of straightness helps ensure proper alignment with connecting members and overall stability, which is crucial for the performance and safety of the entire assembly.

In the context of the other options, variations like 1/4", 1/2", or 3/16" might not align with the prescribed tolerances and could compromise the truss's effectiveness in a structural application.