HOME IMPROVEMENT : Doing Wall Detective Work: Finding Studs

Every year, thousands of people, especially children, are seriously injured by improperly mounted objects falling off the wall.

Whether you own or rent your home, sooner or later, you will have the need to anchor a heavy picture, mirror, bookshelf, wall unit or other item on a plaster, wood panel or drywall surface.

To do it safely, the mounting hardware should be secured to the vertical lumber (studs) inside a plaster, wood panel or drywall surface.

Finding the studs can sometimes be tricky because they are hidden inside the wall. One sure-fire but undesirable way to find a stud is to drive a nail into the wall at one inch intervals along a horizontal line in the area where you want to hang the heavy object until you feel the resistance of the nail penetrating solid wood.

This method is both time consuming and damaging to the wall. Here are some ideas for making stud finding a lot easier:

Use an electronic stud finder. Another terrific spin-off of the electronic revolution for home improvement is a device called an electronic stud sensor. This tool is battery powered and operates by sensing changes in the wall density that indicate the presence of a solid object inside the wall.

This instrument is about the size of a pocket calculator and works by slowly moving it across the wall surface in the mounting area until a row of lights illuminate, indicating the stud location. It is sold under the brand name Studsensor and is manufactured by Zircon International Inc. Most hardware stores and home centers carry it; prices range from $10 to $20.

Measure from known studs. Although the electronic stud sensor is the best device on the market for stud finding, it is not 100% accurate. Sometimes non-standard wall construction or other obstructions in the wall result in either false readings or no reading at all. That’s where the old-fashioned method of measuring from known wall studs is handy to know.

During construction of a home, wall studs are normally placed 16 inches apart. Since room corners and door and window edges are always framed by studs, try measuring out horizontally from these points. Odds are that you will find studs at about 16-inch intervals.

For example, if you have a door and a window on a wall that are 8 feet apart, studs will normally be found between the door and window at 16, 32, 48, 64 and 80 inches.

When you have noted the multiple of 16 inches from the known wall stud in the desired mounting area, drive a thin nail into the wall to determine your accuracy. If you miss the stud, try the nail again one inch left or right of the first hole.

Another variation on this technique is to measure laterally on the wall from the edge of light switches, electrical outlets or heating/air conditioning registers because these are always mounted on wall studs during construction.

When measuring from a heat/AC register, hold the end of the tape at either the left or right of it, as there are studs on both sides. When measuring from an outlet or switch, try either side first since they attach to only one stud. If your first attempt is incorrect, try measuring from the opposite side.

Knock on the wall. Still another method of stud location is to literally knock on the wall several times at the desired mounting location, and then left and right of it. A hollow sound means there is no stud, while a solid sound means you have probably hit the jackpot.

Try the nail test at the spot where you hear the solid sound to assure that you have indeed found the stud.

Look for dimples on the wall. The least consistent, but often successful stud finding technique to try on a drywall surface is to look for depressions or “dimples” on the wall that indicate nails.

During construction the drywall sheets are nailed to every wall stud, and then the nails are covered with a thin layer of compound to give a smooth, finished surface. Sometimes, though, the finish work on the wall is not as good as it should be, and with very close examination, slight dimples can be seen where the nails penetrate the drywall into the studs.

If you find such an irregularity in the mounting area, you can be almost 100% certain it indicates a stud.

When looking for wall studs behind a wood panel wall, look closely for colored nail heads in the grooves of the panels. Any nails you find probably penetrate a wall stud behind the paneling.