How to find studs before you mount a TV

A TV bracket is only as strong as what its bolts bite into. On a framed wall that means studs — the vertical 2×4s hidden behind the drywall. Finding them is easy to get almost right and surprisingly easy to get wrong.

1. Start with the layout

Most framed walls put a stud every 16 inches, measured from a corner. Outlets and light switches are almost always nailed to the side of a stud, so the edge of an outlet box is a strong clue. Measure 16 inches from there and you have a first guess.

2. Use a stud finder — as a hint, not a verdict

Electronic stud finders sense a change in density. They also beep at drywall seams packed with joint compound, metal corner bead, plumbing and doubled framing around windows. Slide it from both directions and mark where it starts and stops; the stud's centre should be halfway between.

3. A magnet finds the screws

A small rare-earth magnet dragged across the wall will snap to the drywall screws. Screws run in a vertical line down each stud, so two or three hits stacked above each other mean you've found one.

4. Knock and listen

Tap along the wall with a knuckle. Between studs the sound is hollow; over a stud it turns dull and short. It's rough, but it's a fast way to double-check a mark.

5. Confirm with a probe

Before drilling a ⅜″ hole for a lag bolt, we push a thin finish nail or awl through the drywall where the bracket will hide the hole. Solid resistance after half an inch means wood. If it pops into empty space, the mark was off. Probing left and right also finds the stud's edges, so the bolt goes in the centre and not the corner.

Things that fool people

• Studs at 24 inches. Some interior and exterior walls are framed wider.
• Metal studs. Common in apartments and condos; a magnet sticks to the stud itself, top to bottom. They need different hardware — see our metal studs guide.
• Plaster and lath. Stud finders are close to useless on it; see mounting in plaster walls.
• Fire blocking. A horizontal board between studs can read like a stud if you scan up and down.

How many studs does a TV need?

For anything wider than about 40 inches we want the bracket bolted into two studs. One stud can carry the weight, but two stop the bracket from twisting when you pull the TV away from the wall.

Checking studs properly is part of every mount we do; labor starts at $94.