For construction projects large and small, wall studs represent one of the most basic elements of the structure. Understanding the various types of wall studs and their specific function in a framed wall helps to explain how these key members work together to support the internal "skeleton" of a house. Wall studs can be either metal or wood, but the types used in framing and their uses are the same.
Standard Wall Studs
These studs are the most basic type and are typically installed vertically in the wall assembly. They are spaced either 16 or 24 inches apart, extending from the horizontal bottom sill plate to the top plate. Standard pre-cut wall studs are 92¼ inches in length for the most common residential wall framing where the total wall height is typically 8 feet.
Trimmer studs are placed at each side of a door or window opening, "trimming" the opening to size, and support the structural header beam that spans the opening, which carries the wall and roof load above it. In addition, any wood member that is inserted in an opening, with or without a header to support, will be referred to as a trimmer.
Typically, corner studs are actually three standard full-length studs assembled to form the corner junction of two perpendicular walls. Two of the studs are parallel to each other, with a third positioned at a 90-degree angel between them and held flush with the surface that will be the exterior face of the wall.
Cripple or Jack Studs
This type refers to any vertical wall stud that does not extend full-length between the sill plate and the top plate, such as those that support horizontal window sill plates or fill the space between the top of a header and the top plate. Cripple studs are also defined as the studs in any wall section that is less than the standard wall height of 8 feet, referred to as "pony" walls, such as those that support bathtub or water heater platforms.