In terms of lumber sizes, what does the designation "2 x 8" refer to?

The designation "2 x 8" refers to the nominal size before milling, which is a common terminology in the lumber industry. This sizing indicates the rough-cut dimensions of the lumber before it is planed and smoothed during processing.

For instance, a piece of lumber labeled as "2 x 8" has a nominal thickness of 2 inches and a nominal width of 8 inches. However, after these pieces undergo milling, they will lose material to achieve a finished look, resulting in actual dimensions that are smaller. Typically, a "2 x 8" will actually measure about 1.5 inches by 7.25 inches once processed.

Understanding this distinction between nominal and actual sizes is important for carpenters and builders, as it impacts the planning and execution of a project, ensuring that components fit together as expected. The other choices refer to dimensions that do not accurately reflect the lumber industry's terminology related to sizes prior to milling.