The minimum sized lumber for a shed exterior wall is 2×4. Since 2×4 lumber is 1.5” x 3.5”, your walls aren’t as thick as you’d think. However, we know that your shed walls will be more than just studs. The sheathing is anywhere from ⅝” to ⅜” thick. Siding can range from ½” to 1” thick. Therefore, you are looit at a