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While preparing for a TV mounting on a wall, I've read on various answers here that the standard spacing is 16 or 24 inches between studs. I've run into a weird situation where there are 3 studs A, B, C. Distance between A and B is 6 inches, and B and C is 16 inches.

Is it possible to have two studs only 6 inches apart? I'm just trying to ensure my stud finder is not detecting a PVC pipe or something.

I'm trying to look for the closest two studs to the center of the room for a TV mount and they turn out to be A and C, but looking for some help to see how to ensure it's indeed a stud and nothing else.

This is the stud finder I'm using.

Edit: Wow! what an awesome response! Given the interest, I decided to go through the entire wall using my stud finder and map out all the studs (or at least that I think are studs). I then annotated it on the pic I took of the wall where I'm trying to put the TV. Pic attached. A few notes:

  1. 2001 construction

  2. This is on the 2nd floor, and I have access to the attic above this ceiling.

  3. Studs are at varying spacing across the wall.

  4. Studs A, B, C in my original post are 4,5,6 in this pic.

  5. Stud #9 shows 1-2 inches wide by the stud finder.

  6. I did the 'knock, knock, Thud!' test and it sounds almost identical for all studs.

Here's the pic of the wall with annotation

As you can see, I'd like to use stud#4,6 for mounting the TV Mount plate. So the main stud in question is #4. I think #5 is surely a stud as that's what the outlet is attached to. I want to avoid using stud 5,6 since that puts the TV off-center by 6-7". Any further help would be appreciated!

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  • I'd guess #9 is a false reading, the others are vaguely plausible.
    – Criggie
    Jan 30 at 6:10
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Yes. They can be however far apart the builder wants them. I have used 3-4 studs within 16" when doing bathrooms, high traffic corner, in bathrooms for showers... and have installed an extra stud because of a previous mistake.

I only use magnetic stud finder (finds your screws).

If you use a method and you just aren't 100% sure the best thing to do is a test with a monkeyhook. These take literally 10 seconds to test with no equipment and only leave a tiny pinhole. If you hit something... boom got a stud. If you don't no one will notice (you can cover the pinholes with similar colored toothpaste!). Also monkeyhooks are great for holding smaller picture frames.

Also adding based on comments on plumbing:

Paramagnetic metals are weakly attracted to magnets, and include platinum, tungsten, aluminum and magnesium. Ferrimagnetic metals like magnetite are also attracted to magnets, while diamagnetic metals like silver and copper are repelled by them.

Your magnet will slightly repel (and have tested) on copper (obviously stud finder or magnetic stud finder will not find pex).

To add specifically to mounting: You can remove drywall and add cross bracing. You are basically ruining that small section anyway. If you want to beef it up - it takes 30 mins.

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  • +1 for using a (strong) magnet to find screws, rather than the often vague electronic studfinder (I own one, I've learned to be dubious of what it thinks, though it's not quite to the point of throw it in the trash.) If it's seeing a pipe or conduit or wire, the builder will not have put screws into those (we hope!)
    – Ecnerwal
    Jan 29 at 14:36
  • @Ecnerwal - can't recall the last time I saw someone use an electronic stud finder at my homes. I certainly would question their ability - if they think being right 70% of the time is good enough. If we are doing major screwing we will hit the stud with a monkeyhook - and all of my crews know this. These are so wobbly they won't damage plumbing or electric and you can hear it hit a duct.
    – DMoore
    Jan 29 at 16:25
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    I don't have any problems with my electronic stud finder; it has stood me in good stead. Searching for a screw with a magnet is a 2D search; searching for a stud is a 1D search. Combine both: find a suspected stud, then search vertically for a screw with a magnet.
    – Kaz
    Jan 29 at 17:51
  • @kaz - i am fine with that if you verify with a magnet... yours seems like an extra step though. The other thing the magnet does is it allows you to try not to put a big screw on another... not foolproof but helps.
    – DMoore
    Jan 29 at 21:29
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    A good quality electronic stud finder can locate the edge of a stud within about 1/8 inch. Checking both sides of the stud should produce about a 1.5" difference, and you should find that the stud (in "normal" cases) is in the same position up and down the wall. Mistaking a water pipe for a stud would be quite difficult/sloppy.
    – Hot Licks
    Jan 29 at 22:13
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You are correct to hang a TV (or anything else "heavy") from a stud or other building structural member.

This provides reliable support under static and dynamic loading (think: weight, moment-arm, any leaning, minor earthquakes, vibrations from door slams), and ensures the wall material does not bend or crumble or crack over time.

When you use a stud finder or a "small-nail technique" to find structural members, it's a good start but it is not definitive.

Here's what else you might run into behind the drywall, masquerading as a stud:

  • drain pipe (e.g. black ABS)
  • water line
  • hvac wall ducts
  • drywall backing (panels or strips screwed to the back of drywall for support and alignment at seams
  • junk stuffing (drywall cuttings, other building material) left in the wall to spare disposal costs or to provide acoustic insulation.

I have seen screws from electrical wall mount boxes penetrate into PEX water line behind it, garage shelving installed into ABS drain pipe, etc..etc... None were obvious mistakes at first sight. But over time they became a major headache to discover and fix.

Do not assume that anything critical in the wall is protected by an impenetrable metal cover. And if you are in a multi-dwelling, who knows what service lines are in the walls, even in your unit's inner walls.

When I install anything onto a wall stud or ceiling joist, and I want to make sure it's supported by building structure and not any thing else, this sort of summarizes my approach:

  1. start with a stud finder, ensure you detect the stud consistently at different heights
  2. confirm spacing with other neighbouring studs (as you have done), usually 16/24in horizontally for studs, or 24/48in vertically if there is horizontal strapping in an outside wall. Stand back and look at the larger picture, does it makes sense that there's a stud there?
  3. what is in the room above or below? Could it be drain or water or hvac?
  4. skim the wall with a flash light (e.g. from your cell phone), to spot blotches or bumps that hint at drywall screws. If it's a stud, the screws align top to bottom.
  5. drill an inspection/confirmation hole, perhaps 1/4-in diameter, and visually confirm it's a stud. These holes are easy to fill if you missed, and if it's confirmed to be a stud the hole gets covered by the bracket anyway.
  6. For more critical applications, e.g. a hanging chair, or a very heavy extension wall mount requiring more than a #8 screw, I drill a larger hole, perhaps even 1-in for better confirmation, to ensure the mounting fastener is centered in the stud. Alternatively I install a bracing panel first to cover more studs, just in case some of the spotted wood is not a stud.
  7. Pray, sweat, and eventually sell the house

Do not screw more than 1-in deep behind the drywall: most lines, but not all, are at least 1.25in away from the stud edges. If you need more support, apply more fasteners.

To your question about stud spacing, it can vary for many reasons:

  • usually it is 16-in or 24-in: this makes it easy to "panel" drywall boards (a.k.a sheets or gypsum wall board), since their 8feet or 4feet lengths are multiples of 16 or 24-in.
  • studs can be doubled, with zero spacing or 1..2-in spacing, for more support, e.g. around stairs, windows, other openings, walls in the room above,...
  • stud-lumber can be used as backing, to provide backing for the drywall panels if the seems do not align with the existing framing: dimensional lumber (stud lumber) is nailed/screwed to another stud to make it "wider" behind a drywall seam. It could provide good support for a mount, even if it does not reach the full length from the top to the bottom plate.
  • it provides support for something on the other side of the wall (a Tee-ed wall, a shower door etc...)

Good luck! Luck helps.

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  • 1
    Could also be a wall on the other side there... A "C" shape of studs is common at a joint like that, and would leave the two outer studs about 6" OC.
    – IronEagle
    Jan 29 at 17:41
  • Indeed @IronEagle, good point on the 6in. I'll edit my answer where I mention the Tee-ed wall. Thanks. Is the calculation 3.5in plus 2x 3/4in = 5in OC = about 6in?
    – P2000
    Jan 29 at 18:02
  • That was my reasoning. The older the house, the closer it is to 6”.
    – IronEagle
    Jan 29 at 18:36
  • A seven point list on how to use a stud finder, ending in 'pray that you're right' - that's about how it goes every time, +1.
    – Mazura
    Jan 30 at 2:19
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16 is a typical maximum spacing, there is no restriction on having more, it just may be overbuilt.

It can be quite common to encounter studs that are doubled up or have strange intervals.

Common causes are framing of windows or doors, made especially strange if the window or door is no longer there. Same with changes to load bearing wall situations can leave behind mysterious widths. And of course, near corners because walls are often not even multiples of 16".

If you're not sure if you are getting a false reading or not, you should be able to tell if a stud is there or not by sound, pounding your fist on the wall.

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    Another sure way to find a stud is to drive a small finish nail into the center of where the stud finder says there is one. Tap, tap, tap, woosh and the nail disappears - there wasn't a stud. Tap, tap, tap, thud, thud, thud - yup, thar be a stud!
    – FreeMan
    Jan 29 at 12:36
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    @FreeMan - you need a bigger hammer! Should be just - tap, thud!!!
    – DMoore
    Jan 29 at 16:26
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    The goal, @DMoore, is to determine if there is actually a stud there, not nail up the drywall... :D
    – FreeMan
    Jan 29 at 16:47
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    @FreeMan: while true, using your fist is considerably less invasive. Jan 29 at 17:08
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    Knocking is helpful, but if there are 2 studs just a few inches apart, the sound difference may be minimal, @whatsisname. A thin finish nail doesn't make a big hole, will be hidden behind the TV/mount, and when it's time to move out, will easily be filled when fixing up the much larger holes left by the mount's lag bolts.
    – FreeMan
    Jan 29 at 18:54
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Welcome to old houses.

16 inches is the standard stud spacing (means a 4x8 foot sheet of drywall or sheathing plywood is supported by 3 studs vertically and 7 horizontally.

Why do we build modulo 4 feet? Because, back in the days of plaster and lath work, dating back centuries, lathing (done by a lather) is a specialized trade of its own. Lathers would break the lathe into convenient lengths to work with (because working with a 12 foot or longer piece of wood is awkward). As it works out, about the longest practical convenient length is 4 feet.

And old houses, over time, get... modified [some might say "improved", but not all modifications are improvements]. Our house has alls with stud spacing all over the place, compounded by studs that have been sistered.

If you wan a fool-proof way to identify where the studs are, pop the baseboards off. Take your electric drill and chuck a [longish] 1/16th bit into it. Start drilling little holes every 1/4 to 1/2 inch apart, 2-3 inches above the floor (but still where it would be covered by the baseboard). You're at a stud when the bit finds solid wood; not at a stud where all you get is plaster or gypsum and air with maybe a little wood from the lath.

Of course, then you have to worry that the stud is actually vertical.

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Option 1: You have access to the attic above? Great! If you can lift some insulation and see the top plate, then look for pairs of large nail heads. These will be driven down through the top plate and into the ends of the studs. Measure off and see if they match up with your diagram.

However I'd start with

Option 2: Carefully remove the power socket face plate (It will have live wires inside, so consider turning off the circuit) Then you should be able to see the box behind is screwed into a stud, confirming exactly the location of your stud #5

Third, use a thin metal ruler and slip it horizontally into the hole in the drywall. Poke it between the electrical box and the drywall and feed it rightward until you feel it hit the next stud. Clonk it to make sure by the sound. That will identify your stud #6

Frankly I wouldn't worry too much about stud #4, once you've found 5 and 6. Two lag bolts into each stud, four in total should be enough to hold the TV.


While you've got the wall plate open, after mounting the TV bracket, then consider installing a power outlet up behind the TV. You might also install a pair of brushmouth hole covers to get signal cables up from any AV equipment so they're not visibly dangling, adds tidiness.

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    Regarding option 2, best to confirm the wood that holds the box is a stud and not a stub: check for screws marks / blotches all the way up.
    – P2000
    Jan 31 at 2:47

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