Which material is defined as dimensional lumber?

Dimensional lumber is primarily defined as lumber that has specific nominal dimensions, typically ranging from 2 inches to 4 inches in thickness. This category includes commonly used sizes such as 2x4, 2x6, and similar sizes that are essential for framing, construction, and other structural applications. These nominal dimensions correspond to actual dimensions that are often slightly less due to the drying and planing processes.

The options that describe materials with greater thickness or engineered products do not fit the definition of dimensional lumber. While glued laminated wood and engineered wood products are significant in construction, they have different characteristics and applications than traditional dimensional lumber. Therefore, identifying dimensional lumber as a material with a nominal thickness of 2-4 inches accurately reflects its industry standard and usage in civil engineering and construction.