We’ve all been there at some point: anxiously trying to find a wall stud while you’re in the process of hanging a picture, shelf, or TV mount. Most stud finders are inconsistent at best, and I’ve found the more I learn about how houses are built, the easier it is to find a stud through logic instead of equipment. In lieu of buying yet another tool, here are a few tips for finding a stud without any fancy equipment.
Understand wall construction
Every house is different, but there are a few things you can count on. More modern stick-framed houses (anything built after 1920 or so) is likely built with 2×4 or 2×6 studs. Some things you should know about how walls are framed:
- Studs are generally spaced between 40-60cm on centre (which means from the middle of one stud, to the middle of one next to it.) 40cm is the most common dimension though.
- You will also find studs on either side of a window or door, but their placement is determined by the floor plans so they won’t typically have the 40cm spacing.
- Most electrical boxes (switches or outlets) are attached to a stud on one side.
- The actual dimensions of 2×4 lumber vary based on the date the house (or the particular wall of the house in question) was built. For example, between 1900-1950, rough cut 2×4’s were most common and were actually two inches by four inches, for the most part. Houses built between 1950-1965 might have 2x4s that are 1-⅝ by 3-⅝ though, and more modern 2x4s are actually 1-½ by 3-½ (all of which matters if you’re trying to measure from the centre of one stud to the next.)
- Trim (crown moulding, baseboard, and shoe moulding) is generally nailed to a stud.
Look at the trim
Since the baseboard should be attached to the studs, look to see if you can spot where it might have been nailed. These holes — dimples — are generally filled with caulk and painted, but you may be able to spot one to identify the location of a stud. If you find one, try measuring in 40cm increments to locate the additional studs.
Locate the switches
If you don’t have any luck checking out the trim, look for switches or outlets, knowing that at least one side of an electrical box will be mounted on a stud. Personally I’m not great at doing the “knock test” on the wall, but I can usually detect from tapping which side of the outlet is attached to the stud. Then you can measure about 2cm away from the outlet on the stud side and use that as the starting point to determine the 40cm intervals.
Measure from the corner
With studs generally 40cm on centre, you can also do calculations from a corner of the room. This method can be a little iffy, because all rooms aren’t built in numbers divisible by 40cm, so you are likely to have a stud that is less than 40cm from one corner. Try the “knock test” near the corner to see if you can determine where the shorter stud-spacing might have been added. This only really works if you’re measuring a corner off the exterior of the house, but there may be a situation where this helps (and it’s certainly better than blindly drilling a dozen holes in your wall, hoping to hit a stud.)
Also, one of the very best ideas I had when building the addition on my last house was to take pictures of every wall in every room after they were framed in but before we hung the drywall. Those reference photos came in handy more times than I can count after the drywall was up.
This story was originally published in September 2014 and was updated November 10, 2020.