A wall stud is a vertical board that is mounted within a wall structure as part of the framing of a building. A wall is likely to feature more than one stud spaced at regular intervals across the width of the wall, and they will be present at each corner of a structure as well. The point of these studs is to support the weight of the walls as well as the ceiling or floor of the level above, and in some cases, the studs may also be responsible for supporting the weight of the floor below.
The size of the wall stud can vary depending on the type of structure being built, though all the studs within a particular structure are likely to be a uniform size. Wood is the most common choice of materials for a wall stud, though some types of metals are used as well; metal studs are used for strength, durability, and in some cases, to dampen noise transmission, but they also tend to be more expensive, more difficult to cut, and more difficult to install than the easy-to-use wooden wall stud units.
Two general types of walls exist: load bearing walls and non-load bearing walls. A load bearing wall will support the weight of the ceiling or upper levels of the structure, while a non-load bearing wall will not support any weight but its own. Sometimes walls are built simply for aesthetics or for creating divisions within a room or section of a building, or even to conceal electrical wires or plumbing and heating ducts. These walls are usually non-load bearing, which means the wall stud units within the structure will not support any weight. A load-bearing wall will need to be built differently; the boards, or plates, that sandwich the studs from the top and bottom will usually be double built, which means two pieces of wood will be stacked on top of each other to provide additional support and stability.
It is likely that a wall stud will be screwed or nailed directly to a plate, though in some cases, special hardware may be used for added stability or ease of installation. In other cases, the studs themselves may not run directly from the ground to the ceiling; this is common around windows and doors, so other building techniques must be used to properly frame the wall for stability and safety.