What is the thickness of the stud in the exterior wall?

The thickness of the stud in the exterior wall typically refers to the most common size used in residential framing, which is the 2x4 stud. Although the nominal size of a 2x4 stud is 2 inches by 4 inches, when you measure its actual thickness, it is approximately 3-1/2 inches. This measurement reflects the standard production size adjusted for planing and finishing.

Understanding this common dimension is crucial for accurately interpreting construction drawings and ensuring proper framing practices are applied, especially in exterior walls where structural integrity and insulation are critical. The other thickness options, such as 4-1/2 inches, 2-1/2 inches, and 5-1/2 inches, do not represent standard dimensional lumber sizes used for typical interior or exterior wall framing in residential construction.