Dimensional lumber is cut to specific standardized thicknesses, widths, and lengths. This lumber has various applications, and manufacturers often transform it to fulfill them. Dimensional lumber can come from both softwoods (cypress, redwood, and juniper) and hardwoods (oak, walnut, and mahogany). Softwood dimensional lumber forms the skeleton of houses, while hardwood dimensional lumber serves as flooring. Other hardwood applications include crafting, packaging, and concrete forms.
Examples of popular dimensional lumber sizes are 2 inches by 4 inches (2x4) and 4 inches by 4 inches (4x4). These numbers refer to thickness and width. However, these are not the actual sizes of dimensional lumber. A 2x4 is 1 1/2 inches by 3 1/2 inches, while a 4x4 is 3 1/2 inches by 3 1/2 inches.