Wall stud

Double metal studs designed to reduce noise transmission.

A wall stud is a vertical member in the light frame construction techniques called balloon framing and platform framing of a building's wall.

Purpose

It is variously also called "stick and platform", "stick and frame", or "stick and box" construction colloquially; the 'sticks' carry the vertical loads, and the rectangular platforms made of floor joists, headers and sub-floors, hold the outward forces in check and keep the walls in parallel and from bulging. In the mostly obsolescent and now rare balloon framing method, the wall studs are very long and tall and run from sill plate to roof plate, with the walls holding up the floors. In tall balloon framed buildings, studs are usually augmented by substantial posts, especially in the corners or midpoints of long walls.

Properties

The "sticks" refer to the wall studs and the wall plates which are much thinner in cross section than the structural elements in the older, post and beam and balloon framing methods of light frame construction. Being thinner and lighter, stick construction techniques are easier and speedier than the older methods, and balloon framing has been made illegal in new construction in many jurisdictions, for fire safety reasons—the plates and platforms in platform framing providing an automatic fire stop inside walls, and so are deemed much safer by fire safety officials.

Traditionally, studs were made of wood, usually 2×4 or 2×6 dimensional lumber. In North America, studs are typically placed 16 inches (406 mm) from each other's centre, but sometimes also at 12 inches (305 mm) or 24 inches (610 mm). Steel studs are gaining popularity, especially for non load-bearing walls.

Other terms

Studs used to frame around window and door openings are given different names, including

• king stud − stud to left or right of a window or door that is continuous from the bottom plate to the top plate
• trimmer or jack − stud to the left or right of a window or door that runs from the bottom plate to the underside of a lintel or header
• cripple stud - a stud located either above or below a framed opening, that does not run the full height of the wall
• post or column − a doubled or other integral multiple of a group of studs nailed side by side, or (equivalent, a metal sheathed concrete filled column) used in a load bearing wall to transfer the weight of an upper structure to the bearing wall of a foundation, footing, and ground. Posts in walls are most common near high decorative windows, long spans near a wide window or sliding door, and other locations where architectural beauty conflicts with the need for engineering strength and safety.

Grades

Based on the WCLIB grading rules, there is only one grade of stud: STUD. A stud is graded for vertical application, and its stress requirements and allowable visual defects reflect that application. A stud is most similar to a #2 grade, which is held to a higher standard during grading. The biggest difference between the two is the frequency, placement and size of knots and overall allowable wane.

Locating studs

When mounting an object such as a shelf to a wall and maximum strength is desired, the goal is to attach the object to the studs in the wall, as drywall or plaster will take significantly less weight.

Using a stud finder, one can easily locate studs in most walls, though this may not work on very thick plaster, or plaster walls built with wire-lath.

If a stud finder does not work or is unavailable, it is often the easiest to tap lightly on the wall with the underside of one's fist. The resonating vibration especially from plaster and drywalls is an indication for a cavity behind. Tapping against a stud usually results in considerably less vibration. Another practice is to use a hammer and lightly tap on the wall while listening for sound differences until the stud is found. A third option is to resort to trial and error. Drilling a hole into the wall with a masonry bit, the difference between hitting a stud and not will be clear. If a stud is not hit, the bit will punch through quickly, with no resistance after the plaster or drywall. If a stud has been hit, the bit will put up considerable resistance. The bit may still drill into the wood or the metal, but progress will be slower. This is more manifest with a masonry bit than a wood drilling bit. After the first stud is found, others will typically be found 16 inches (about 40 cm) in either horizontal direction.

See also

• Framing (construction) which details each of
  • Balloon framing
  • Platform framing
• Post and lintel
• Post and Beam
• Walls
• Wall plates
• Furring