Hidden studs and joists can be located in several ways. Most studs are spaced 16 or 24 inches apart, from center to center. To locate a stud or ceiling joist, measure out from a corner in multiples of 16 or 24 inches (depending on how the structure was built). Then lightly tap the area to find a section of wall with a solid backing (a stud or joist).

If you are unsure of the locations, you can buy a handheld electronic device called a stud finder. This device will beep or flash when it passes over a solid framing member; simply slide the finder along the surface until it signals the location of a wall stud or joist, and then find others by measuring (one will usually be located 16 or 24 inches from there).

Find studs behind plaster walls by driving a small test nail just above the baseboard.

Often, the easiest way to find studs is to look for visible signs of the nails that hold wallboard to the studs--small dents or nail heads.

Hold a strong flashlight at a sharp angle to the wall or ceiling to highlight them.