How to use metal (??) wall studs?
February 4, 2024 9:57 AM Subscribe
I would like to attach various things to my wall. The common advice seems to be that is the thing I'm attaching to the wall is heavy, I need to use a stud. But I think that the studs in my wall may not be made of wood. I have no idea how to navigate this. Help!
Some observations I've made:
1. My understanding of how stud finders are supposed to work is that there are magnetic screws in the wooden studs, and the stud finder helps you find those screws. But when I use a stud finder on my walls, instead of there just being a few magnetic points, there's a very large magnetic area.
2. When I drill a pilot hole into the wall near the magnetic area, the drill bit stops and hits a thing that feels like metal
Some questions:
1. How can I tell if my studs are made of metal? Is there another explanation for what I'm seeing?
2. Do people attach things to metal studs? Is that a normal thing to do?
3. How do I tell the difference between a metal stud and some other scary metal thing in my walls, like electric wires? Especially if the place in the wall I'm interested in is near an outlet or other electric wiring.
4. What kinds of things do I need to buy to be able to attach things to the metal studs? I have a handheld electric drill and some drill bits, but maybe the wrong drill bits.
Explanations at a pretty basic level would help me, I know how to use a drill and how to use anchors to put screws in drywall but that's about it.
Some observations I've made:
1. My understanding of how stud finders are supposed to work is that there are magnetic screws in the wooden studs, and the stud finder helps you find those screws. But when I use a stud finder on my walls, instead of there just being a few magnetic points, there's a very large magnetic area.
2. When I drill a pilot hole into the wall near the magnetic area, the drill bit stops and hits a thing that feels like metal
Some questions:
1. How can I tell if my studs are made of metal? Is there another explanation for what I'm seeing?
2. Do people attach things to metal studs? Is that a normal thing to do?
3. How do I tell the difference between a metal stud and some other scary metal thing in my walls, like electric wires? Especially if the place in the wall I'm interested in is near an outlet or other electric wiring.
4. What kinds of things do I need to buy to be able to attach things to the metal studs? I have a handheld electric drill and some drill bits, but maybe the wrong drill bits.
Explanations at a pretty basic level would help me, I know how to use a drill and how to use anchors to put screws in drywall but that's about it.
Stud finders aren't metal detectors as such. They detect changes in the dielectric constant of the materials in the wall. The fact that you're finding a large area with the stud finder suggests to me that you're as likely to have wooden studs.
My stud finder has a setting for locating electrical wires and copper pipes, so I check with that if I'm uncertain, but stud spacing tends to be even in most walls, so that'll help tell you you've located a stud and not something else.
If your studs are wood, then the drill bit should come out of the wall with bits of wood on it. If they're metal, you may feel a lot of resistance, followed by a 'pop' as it goes through the relatively thin metal. You'll need a drill bit suitable for steel, and very sharp, to drill into metal.
Wires usually run vertically up or down from a socket or switch (at least in my country). But don't rely on that to be true in all cases.
posted by pipeski at 10:31 AM on February 4 [2 favorites]
My stud finder has a setting for locating electrical wires and copper pipes, so I check with that if I'm uncertain, but stud spacing tends to be even in most walls, so that'll help tell you you've located a stud and not something else.
If your studs are wood, then the drill bit should come out of the wall with bits of wood on it. If they're metal, you may feel a lot of resistance, followed by a 'pop' as it goes through the relatively thin metal. You'll need a drill bit suitable for steel, and very sharp, to drill into metal.
Wires usually run vertically up or down from a socket or switch (at least in my country). But don't rely on that to be true in all cases.
posted by pipeski at 10:31 AM on February 4 [2 favorites]
imo magnetic stud finders would be of limited utility because there's a lot of things in a wall that could be magnetic and also there just might not be enough nails/screws to detect where you want to find a stud. i use an electronic stud finder that measures the capacitance of the wall that indicates studs based on differences in the dielectric constant. i use one similar to this.
1. a lot of my wall work is done in commercial locations with drop ceiling, where i can look above the ceiling and often see the exposed studs above where the sheetrock ends. but also often i just start drilling a hole to mount the thing i'm mounting (usually a tv or monitor mount) or even just start sinking a drywall screw and if it stops sinking at a certain point and just spins, it's most likely a metal stud. a drywall screw will easily bite into a wood stud but won't hardly bite in a metal stud at all unless it's a self-tapping drywall screw.
2. all the time. totally normal.
3. some stud finders have wire detection but i don't have experience using those. the key thing for finding studs is the regular pattern in the wall. they are usually 16" inches apart, sometimes 24", rarely but possibly on some less regular pattern depending on the location and structure of the wall. if my stud detector is indicating a stud here, then also another stud 16" inches to the left, and another stud 16" to the right, then the initial spot is almost certainly a stud. usually the electric wiring inside the walls can be guestimated once you know where the studs are. electrical boxes are commonly mounted to the side of a stud before the sheetrock is put up, so if you have an electrical box and you can tell where the stud is, the wiring for it will probably be run inside the channel between the studs containing the electric box, and the horizontal wires running back to the breaker box are usually down pretty low in the wall, below where the outlets are. of course nothing accounts to the quirks of a particular site, but those are the general guidelines (i'm not an electrician so i can't speak to code mandates).
4. i use toggle bolts. someone else might have a better suggestion, they can be a little tricky.
posted by glonous keming at 10:35 AM on February 4 [2 favorites]
1. a lot of my wall work is done in commercial locations with drop ceiling, where i can look above the ceiling and often see the exposed studs above where the sheetrock ends. but also often i just start drilling a hole to mount the thing i'm mounting (usually a tv or monitor mount) or even just start sinking a drywall screw and if it stops sinking at a certain point and just spins, it's most likely a metal stud. a drywall screw will easily bite into a wood stud but won't hardly bite in a metal stud at all unless it's a self-tapping drywall screw.
2. all the time. totally normal.
3. some stud finders have wire detection but i don't have experience using those. the key thing for finding studs is the regular pattern in the wall. they are usually 16" inches apart, sometimes 24", rarely but possibly on some less regular pattern depending on the location and structure of the wall. if my stud detector is indicating a stud here, then also another stud 16" inches to the left, and another stud 16" to the right, then the initial spot is almost certainly a stud. usually the electric wiring inside the walls can be guestimated once you know where the studs are. electrical boxes are commonly mounted to the side of a stud before the sheetrock is put up, so if you have an electrical box and you can tell where the stud is, the wiring for it will probably be run inside the channel between the studs containing the electric box, and the horizontal wires running back to the breaker box are usually down pretty low in the wall, below where the outlets are. of course nothing accounts to the quirks of a particular site, but those are the general guidelines (i'm not an electrician so i can't speak to code mandates).
4. i use toggle bolts. someone else might have a better suggestion, they can be a little tricky.
posted by glonous keming at 10:35 AM on February 4 [2 favorites]
If you use an actual magnet, you know when you've found a stud because you can find the drywall screws and/or nails up and down it, spaced some way apart. That, at least, will tell you where the stud really is, and it would rule out HVAC duct sheeting (you can't screw drywall into a duct, and I'd bet the duct metal is too far away to attract the magnet).
posted by How much is that froggie in the window at 11:24 AM on February 4 [2 favorites]
posted by How much is that froggie in the window at 11:24 AM on February 4 [2 favorites]
Best answer: How can I tell if my studs are made of metal?
Easiest way is to drill a hole in the drywall that's big enough to look through. If there is indeed a steel stud back there, the tip of a 3/8" twist drill will stop right on it before the full width of the shank has gone all the way through the drywall, but you'll be able to use a 1/8" flat blade screwdriver to chisel the remaining tiny bit of drywall out and get a look at the surface of the stud.
Do people attach things to metal studs? Is that a normal thing to do?
Yes and yes.
Anything too heavy for drywall anchors is probably best secured to horizontal rails or plates that fix back to at least three studs. When I mounted a heavy TV on a bedroom wall at our house, I used six batten screws to fix a 36"*18" piece of half-inch five-ply horizontally across three hardwood studs spaced 16" apart.
The same design would work using self-drilling metal threads to fix the plywood sheet back to steel studs. Just make sure those screws are long enough to go through half an inch of plywood, half an inch of drywall, and far enough through the stud that the drilling tip ends up well past the far side of the steel. Don't overtighten them lest you strip the threads, and probably best not to wind them in and out repeatedly because the inbuilt drilling tip tends to chew up the freshly cut threads on the way out.
Before fixing the plywood to the wall, I had drilled four holes in it to match those on the TV mounting bracket, then hammered tee-nuts into the back of those so I could use 1/2"x1/4" mushroom-headed bolts to fix that bracket to the plywood sheet.
The resulting mount is very solid and completely hidden behind the TV. Doing it this way also let me put the TV exactly where I wanted it on the wall, instead of being restricted to positions where its own mount would span a pair of studs.
posted by flabdablet at 12:20 PM on February 4
Easiest way is to drill a hole in the drywall that's big enough to look through. If there is indeed a steel stud back there, the tip of a 3/8" twist drill will stop right on it before the full width of the shank has gone all the way through the drywall, but you'll be able to use a 1/8" flat blade screwdriver to chisel the remaining tiny bit of drywall out and get a look at the surface of the stud.
Do people attach things to metal studs? Is that a normal thing to do?
Yes and yes.
Anything too heavy for drywall anchors is probably best secured to horizontal rails or plates that fix back to at least three studs. When I mounted a heavy TV on a bedroom wall at our house, I used six batten screws to fix a 36"*18" piece of half-inch five-ply horizontally across three hardwood studs spaced 16" apart.
The same design would work using self-drilling metal threads to fix the plywood sheet back to steel studs. Just make sure those screws are long enough to go through half an inch of plywood, half an inch of drywall, and far enough through the stud that the drilling tip ends up well past the far side of the steel. Don't overtighten them lest you strip the threads, and probably best not to wind them in and out repeatedly because the inbuilt drilling tip tends to chew up the freshly cut threads on the way out.
Before fixing the plywood to the wall, I had drilled four holes in it to match those on the TV mounting bracket, then hammered tee-nuts into the back of those so I could use 1/2"x1/4" mushroom-headed bolts to fix that bracket to the plywood sheet.
The resulting mount is very solid and completely hidden behind the TV. Doing it this way also let me put the TV exactly where I wanted it on the wall, instead of being restricted to positions where its own mount would span a pair of studs.
posted by flabdablet at 12:20 PM on February 4
Best answer: Some great advice here so far. I'd add that there are both anchors designed for these types of studs, and screws that will marked on the box as rated for going into them.
My biggest piece of advice here would be to carefully tighten the screw/anchor, rather than just blasting it in like you would a screw/lag bolt to a wood stud. The hole can strip out pretty quick, just like using a self tapper on any other thin metal...
Normal drill bits will predrill holes into them fine, but a cheapo stud finder will likely struggle. My usual method with these is to just find one, then measure out 16, mark with pencil, 16in, pencil...
posted by emptythought at 5:02 PM on February 4 [1 favorite]
My biggest piece of advice here would be to carefully tighten the screw/anchor, rather than just blasting it in like you would a screw/lag bolt to a wood stud. The hole can strip out pretty quick, just like using a self tapper on any other thin metal...
Normal drill bits will predrill holes into them fine, but a cheapo stud finder will likely struggle. My usual method with these is to just find one, then measure out 16, mark with pencil, 16in, pencil...
posted by emptythought at 5:02 PM on February 4 [1 favorite]
How heavy are the various things that you would like to mount/hang on the wall? Drywall anchors are easy (drill hole, tap in dry wall anchor, screw a screw into drywall anchor) and can support 50#. You should weigh the object you want to mount, it is very hard to perceive weight just by holding it. https://www.homedepot.com/c/ab/how-to-use-a-drywall-anchor/9ba683603be9fa5395fab90075295b6
posted by fieldtrip at 7:16 PM on February 4
posted by fieldtrip at 7:16 PM on February 4
Worth noting that if you have wooden studs, it is required to put metal plates between the stud and the drywall in front of important things like electrical and plumbing, precisely to protect it from people drilling into the studs, so be cognizant of that before getting a better drill bit to drill through the steel you encounter!
posted by rockindata at 7:27 PM on February 4 [6 favorites]
posted by rockindata at 7:27 PM on February 4 [6 favorites]
Rockindata makes a really excellent point above. Have you checked other areas in the house, or just the specific place you want to hang your item? If you can find wood in other areas, but you're hitting metal thick enough to stop an average drill bit in the area you actually want to drill, STOP.
Also, what kind of building is this? These things might vary regionally, but in my part of the US, metal studs are almost exclusively used in commercial buildings. If I thought I had encountered one in a house or apartment, it would be weird enough for me to completely stop what I was doing and rethink my assumptions. Again, this part may be regional though.
posted by Krawczak at 7:52 AM on February 5 [2 favorites]
Also, what kind of building is this? These things might vary regionally, but in my part of the US, metal studs are almost exclusively used in commercial buildings. If I thought I had encountered one in a house or apartment, it would be weird enough for me to completely stop what I was doing and rethink my assumptions. Again, this part may be regional though.
posted by Krawczak at 7:52 AM on February 5 [2 favorites]
Thirding rockindata. Also, to emptythought's repeated measuring out sixteens: especially in an older house, repeatable stud spacings are not super reliable.
Before I put a mounting screw into a stud, I want to be sure that I'm drilling the pilot hole squarely into its centre line. I always verify the position of every stud by using my smallest drill bit to put holes through the drywall at quarter-inch spacings to the left of where I think the centre is until the drill punches straight through drywall into air. These are easy enough to plug with spackle if whatever I'm mounting on the wall would not otherwise hide them, which in practice it almost always will do if it's chunky enough that I've needed to search for studs in the first place.
Drilling tiny exploratory holes and paying attention to what ends up in the drill flutes will also tell you for sure whether you're into wood or steel when you're not into air. And I absolutely agree with Krawczak that as soon as you find one wooden stud, it's way safer to assume that any metal you've encountered elsewhere is probably a protective safety plate.
posted by flabdablet at 8:52 PM on February 5
Before I put a mounting screw into a stud, I want to be sure that I'm drilling the pilot hole squarely into its centre line. I always verify the position of every stud by using my smallest drill bit to put holes through the drywall at quarter-inch spacings to the left of where I think the centre is until the drill punches straight through drywall into air. These are easy enough to plug with spackle if whatever I'm mounting on the wall would not otherwise hide them, which in practice it almost always will do if it's chunky enough that I've needed to search for studs in the first place.
Drilling tiny exploratory holes and paying attention to what ends up in the drill flutes will also tell you for sure whether you're into wood or steel when you're not into air. And I absolutely agree with Krawczak that as soon as you find one wooden stud, it's way safer to assume that any metal you've encountered elsewhere is probably a protective safety plate.
posted by flabdablet at 8:52 PM on February 5
Best answer: An inexpensive borescope can be a great tool for DIYers. Drill a small hole in the wall, and have a look around inside. Just make sure you get one with a light on it. I suggest the self-contained type rather than the type requiring a smartphone; who knows if/when the app will get pulled from the store? Since picking one up, I have found so many uses for this silly gadget, from "what's blocking the drain?" to "which direction does the wiring run from this J-box?" to "I think that rolled under the stove. Did that actually roll under the stove?"
posted by xedrik at 9:05 AM on February 6 [1 favorite]
posted by xedrik at 9:05 AM on February 6 [1 favorite]
Response by poster: Thanks for all the great replies (the borescope especially is a great idea!) I haven't found any wooden studs in my house yet, but I'll look out for that and be cautious. I'm in Canada and our condo is relatively new (built in 2004).
posted by technotaco at 6:37 AM on February 7
posted by technotaco at 6:37 AM on February 7
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In terms of what you might be drilling into, note that it could be something like an HVAC duct, not a stud.
In terms of hanging stuff, note that there are drywall anchor kits that can hold quite a bit of weight (50 pounds, 75 pounds) without a stud. The only thing that I have needed to put into the studs in my house is the TV.
posted by Mid at 10:29 AM on February 4 [2 favorites]