Minimizing False Positives

Is the stud you found really a stud?

  • To properly use a stud finder, scan your work area thoroughly and mark the location of every object indicated by the stud finder. Stud finders work by sensing density changes behind the wall, and other objects can be indicated, especially if they are very close to the wall. Do not assume everything is a stud.
  • Studs are normally spaced 40 cm or 61 cm inches apart, not at odd intervals.
  • Studs normally run from floor to ceiling, except above and below windows, and above doors.
  • Scan for studs at several different heights on the wall. Pipes and other objects will likely not give consistent readings from floor to ceiling, like a stud would.
  • You can switch to metal mode (if it is available on your tool) and scan vertically (up and down) to confirm that the target you’ve found is a stud:
    • If you get a constant metal reading from floor to ceiling, what you found may be a metal stud or metal pipe. A metal signal that suddenly stops or turns 90 degrees to the left or right is most likely a pipe. A metal pipe should also indicate a width of less than the standard stud (normally 38 mm wide) when you scan it in Stud Scan mode.
    • If you get some metal readings in regular increments from floor to ceiling, then you have found a wood stud with drywall screws.
    • If you get no metal readings at all while scanning vertically, the object may be plastic pipe or conduit.
  • Studs are normally 38 mm wide, but humidity and different wall materials may cause studs to be indicated in a different width. However, all of the studs should be consistent in width, and anything that is indicated differently from all your studs is probably not a stud.
  • Always scan the surface using regular Stud Scan mode first. If you don’t find anything, then switch to DeepScan® mode. Use extra caution to confirm that you are finding studs and not something else when using DeepScan® mode.
  • Be aware of walls that are likely to contain plumbing. For example, a living room wall may be common to a bathroom and contain plumbing for the sink, shower, or toilet.