Alternative to Stud Finders
DEAR TIM: I need to hang some cabinets, but I don’t own an expensive stud finder tool. I borrowed one from a neighbor in the past and had limited success with it. Can you share any secrets on how you find wall studs or ceiling joists hidden behind drywall or plaster when you can’t afford an expensive wall stud finder? What are the biggest mistakes a rookie like me can make? How do I prevent making the walls look like a woodpecker was here? How do I repair any collateral damage? Ed R., Warwick, RI
DEAR ED: I hear your lamentations about the electronic stud finders. They are great tools in certain situations, but sometimes they can be really frustrating.
Two years ago, I was using a stud finder tool with a helper and it was giving all sorts of false positive signals. It would indicate where a ceiling joist was behind drywall, and when you drove a nail, it wasn’t there. We even had the house plans and knew the direction of the floor joists.
It turned out that the device was finding them, but that they were recessed from the surface of the backside of the drywall by 3/4 of an inch. The builder’s rough carpenters had installed 1x3 furring strips across the entire ceiling at 90 degree angles to the floor joists. You can see why using these tools requires a knowledge of building habits in certain parts of the nation.
Just this past weekend, I had to find some wall studs to hang wall cabinets. I reverted back to my old-fashioned method of a hammer and a nail. It works well, and because I strategically drove the nail into the wall in certain spots, the cabinets covered the exploratory holes after they were hung.
The first thing I do when I have to find a stud is look for clues as to where they would be. If the house is middle-age or newer, say built after 1950, I look for electrical wall outlets. In almost all situations, the boxes that house the outlets are nailed to the side of a wall stud. In rare instances, a particular wall outlet may have been added at a later date. In these situations a special remodeling box is used that doesn’t need to be nailed to a wall stud.
I’ll also look for poorly patched nail holes in baseboard. This is less accurate because in some places, rough carpenters install a double bottom wall plate. This allows them to randomly nail baseboard trim into the bottom plates instead of a vertical wall stud.
You can also look on a wall for a return air duct if the house has central air conditioning or forced-air heat. Wall registers are commonly put between two wall studs. Remove a return-air grill covering and you’ll almost always see two wall studs.
The general spacing for wall studs is 16 inches on center, but they can be 24 inches. At my current home, the exterior wall studs are spaced at 24-inch centers, but the interior walls are 16 inches on center.
However, just because you find one wall stud’s center location, that doesn’t mean you can say that every other stud on the wall is 16 inches on center from that one. Rough lumber can bow and twist. It’s possible for the spacing to be off by as much as one inch or more either direction, especially half way between the floor and ceiling where studs tend to bow the most.
I use a 10d finish nail when I can to find wall studs. These create tiny holes that are easily patched with spackling compound.
My technique is to find at least one part of the wall stud and then drive nearby holes that tell me where the edges of the stud are. Once I find the edges, and most studs are 1.5 inches wide, I then know where the center of it is.
Old houses that have plaster are a little harder to work in. It requires more effort to drive the nails, and you can get fooled in houses that are old enough to have wood lath that supports the plaster.
If you’re working in a plastered house with horizontal wood lath strips between the studs, you need to find a void space between two pieces of lath. The wood lath strips were often 1 and 1/4 inches wide and the lathers installed them with a 3/8 space between each one.
Drive the nail up the wall until you just go through plaster and hit no wood. When you find this void, start going left and right till you locate a wall stud.
Houses that were built between the 1930’s and the 1950’s had plaster lath boards that were the early forms of drywall. Using this allowed the lathers to be far more productive instead of nailing up thousands of wood lath strips.
These gypsum panels were 3/8-inch thick, 16 inches wide and 48 inches long. In certain situations these would sag and you can see the outline of the seams on the walls and ceilings. Use the staggered 16-inch lines to help you locate the wall studs and ceiling joists. The ends of these panels almost always break on the center of a wall stud or ceiling joist.