North Carolina Building Contractor License Practice Exam

In the designation 56DLH15 for a deep long span joist, what does the number 15 indicate?

1. 1 inch

2. 2 1/2 inches

3. 3 inches

4. 4 inches

The correct answer is: 2 1/2 inches

In the designation 56DLH15 for a deep long span joist, the number 15 specifically refers to the depth of the joist in inches. This standard nomenclature indicates the size and configuration of the joist being used in construction. The correct answer indicates that the depth of the joist is 2 1/2 inches. This specification is critical because it affects the load-bearing capacity and overall structural integrity of the assembly in which the joist is used. Understanding these designations helps builders and contractors choose the right components for their projects, ensuring compliance with building codes and performance requirements. The other options regarding different inch measurements do not accurately reflect the correct designation within this context, as the standard practice uses specific identifiers to denote dimensions clearly and precisely, avoiding any ambiguity in construction materials and methods.