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Discussion Starter · #1 ·
Has anyone wall mounted their plasma on drywall? The conventional wisdom seems to be that you must mount into wood or metal studs. But it seems to me that if you have a sufficiently large wall mount bracket, a sufficient number of toggle bolts around the perimeter should hold the weight of a 42" plasma. (The problem is that I am mounting above a fireplace and there do not appear to be any usable weight-supporting studs.)
 

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Find the studs - there will be some, but they might not be where you want them! So, you put a bit of wood across these to create a frame where you can mount the screen.


Drywall shouldn't be trusted for mounting anything heavy! And if you're not 100% sure about what you're doing, don't DIY. Get a pro.


All the best,


Dr John Sim.
 

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Do you really want to mount a $5k+ plasma on drywall? That's like stringing mikimoto pearls with cotton thread.. don't do it man..


Bryan
 

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wooden 2x4 studs should be every 16 inches.


A stud finder is a great tool for locating them.

If you are not familiar with one they cost around $15.

They detect density changes behind the wall typically indicating the location of a stud.


Drywall is 4'x8' sheets. If you do not detect a stud in that area, your detection method is probably flawed


As said previously drywall will *not* hold the weight of a plasma.


good luck.
 

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I just mounted my 50" above the fireplace a week ago.

It took me a bit of work , but please get a stud finder and map out all the studs in the area you are trying to mount on, pre-drill and use large lag bolts.

I would not trust a multi K$ investment to dry wall. I live in earthquake country but even if you don't, just relying on drywall seems like a poor bet. Imagine a child pulling hard on the wires... disaster all the way around.
 

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dollar2donuts - i think your logic is flawed.


there is no way you could reliably mount a 42" PDP onto 3/4" drywall. it'd be a disaster waiting to happen.


find the studs. never mind the stud-finder IMO - rap with your knuckles and then drive finish nails so you're ONE HUNDRED PERCENT SURE where the stud center is 100% exactly.


be careful. as Abell2218 points out, the risk here isn't just the cost of the PDP - someone is liable to get hurt if something that big and heavy falls on top of them. yikes!


doody
 

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Discussion Starter · #7 ·
Thanks for the advice. Actually, I have a stud finder and there seem to be 2 studs. The problem is that the fireplace and wall above it were added by a prior owner and I don't know what is behind there. The studs are spaced 17-1/2" apart and seem to be only an inch wide, so I am not sure whether they are real studs that can hold any weight.


I agree that drywall would not hold if you pull outward, but anything wall mounted exerts downward pressure, not outward pressure. I would guess that four evenly spaced toggle bolts into drywall would hold at least a couple hundred pounds of downward pressure. Of course, I would not mount a $5K plasma screen based on a guess. I suppose a professional installer would have a sense of what it could hold. If anybody can recommend an installer in New York City, I would appreciate knowing. Thanks.
 

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D2D - Think of your plasma screen as a leaver. At the bottom you've got your axis point, but at the top it's pulling out from the wall. This is what will happen! Yes, you've got downard force, but you've got angular too.


Get a joiner in to have a look at the wall and build a frame where you can mount the plasma screen on to. He might need to have a look at the studs, so he'll cut a hole in to the drywall. The screen's manual should have information on how to mount the screen, so let the joiner have a look at that too.


All the best,


Dr John Sim.
 

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Originally posted by dollars2donuts

Thanks for the advice. Actually, I have a stud finder and there seem to be 2 studs. The problem is that the fireplace and wall above it were added by a prior owner and I don't know what is behind there. The studs are spaced 17-1/2" apart and seem to be only an inch wide, so I am not sure whether they are real studs that can hold any weight.


a 2x4 is not really 2x4, the edge of a 2x4 is more like 1 3/4 and that 1 inch that you are detecting is it. Now something has to be holding that drywall up. If you get a 1/4 screw 1 1/4 inches into that stud, remember to add length to the screw for the drywall and your mount, you will get about 200lbs of support from 1 screw.


Drywall will *not* support the weight. Drywall more or less only supports its own weight, not much more. Think of it like you would sandstone.


Like the post above me states, the angular force will cause it to fail eventually. I'll be impressed if it does not rip right out of the wall when you first mount it.


All that really holds drywall together is a thick piece of backing paper.


Drywall is not intended to carry any weight, it is just facade.
 

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Opps should be 1 3/4 inches of a 1/4 inch screw in the stud for 200 lbs.


Pays to have a dad for a structural engineer.
 

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Discussion Starter · #11 ·
Pays to have a member of this forum with a dad who is a structural engineer. That certainly makes me more comfortable mounting into those studs. Not to belabor the point, but drywall must be capable of holding some weight since people routinely hang framed pictures with picture hangers into drywall. My local hardware store sells picture hangers that are rated up to 100 pounds with three nails into drywall.
 

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I would not hang a 100 lb picture without finding a stud. How long are those nails? if they penetrate more than 1/2 inch that excess is meant for the stud.


At the hardware store or better yet, a construction site get ahold of a scrap piece of drywall. You can break it with your hands.
 

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Discussion Starter · #13 ·
OK, maybe not 100 lbs. The label on those picture hangers does not give me a lot of confidence either. It says "The sale of this product is without any express warranties. Liability, if any, is limited to refund of the purchase price only." So I guess I can get back my 65 cents.
 

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Drywall can, in fact, hold a fair amount of weight with proper mounting. In fact, it might even be able to hold the 100ish pounds of the plasma. The problem is that the weight will wear on any sort of anchoring system you can use. Even the best drywall anchors are going to rely on screws going through the drywall. Even if the screws are "collared" using mollies (sp?) or some other plastic thing the pull of the display will -- over time -- make the holes larger. This will then allow the top to tip foward and rip the display off the wall.


You need to mount the display on studs and -- if the studs are in the wrong place -- pay someone to build new cross members across the studs behind the drywall. You can then patch the drywall -- no paint needed it's behind the plasma.


This is really not an option and $200-400 worth of carpentry is a small price to pay for proper installation of a $5000 television. In fact, you will have a very tough time getting any home insurer to pay a claim if you just mount the thing to the drywall. With a proper install, if it falls (and you've made sure it's covered under your homeowner's/renter's policy) you might well be covered.


This doesn't even account for the fact that if it's done wrong and it decides to "leap" off the wall one day, you could seriously injure or kill someone.


Mark
 

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While I agree that dollars2donuts should not mount the plasma on drywall, lets not assume that there are evenly spaced studs behind the drywall. If the previous owner built the fireplace and wall, who knows what's there. I ran into a similar situation in my new house. I would get a hole saw or a drywall knife and cut a hole and be sure what's there. If you mount the plamsa over it you can leave the hole, maybe even run cables down it. If you want, drywall is easy to patch.
 

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Discussion Starter · #16 ·
Since this is a 2 year rental, I would rather not tear up the walls. I am leaning toward another solution. There is a 4 inch ledge above the fireplace that can clearly support plenty of weight. I plan to have a custom made table stand (my dad is in metal fabrication) that will be only that deep. Then I will anchor the plasma to the wall (probably at the handles) so that it does not tip over. This will not require the wall to bear any weight, but only enough to prevent tipping. I suspect that a toggle bolt or molly screw into the drywall can handle that (although I will try to hit the studs if they aren't too far out of the way).
 

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Dollars: That plan is a good one. Wasn't it Brucer who whipped up a temporary stand at one point? I do agree that toggle bolts/butterfly bolts through the drywall will serve as "tipping anchors". You probably want to see if you can also anchor two points on the bottom of your stand (4 total). If you only anchor the top and someone dancing nearby causes the plasma to "shimmy around", the bottom might try to "walk off" the ledge. With a four-point solution, you'd have the ledge bearing all the weight, but the anchors holding the whole thing against the drywall to prevent tipping -- or slipping.


Mark
 

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Quote:
Originally posted by dollars2donuts
Since this is a 2 year rental, I would rather not tear up the walls. I am leaning toward another solution. There is a 4 inch ledge above the fireplace that can clearly support plenty of weight. I plan to have a custom made table stand (my dad is in metal fabrication) that will be only that deep. Then I will anchor the plasma to the wall (probably at the handles) so that it does not tip over. This will not require the wall to bear any weight, but only enough to prevent tipping. I suspect that a toggle bolt or molly screw into the drywall can handle that (although I will try to hit the studs if they aren't too far out of the way).
Oh Yeah! I can get you the measurements for the taper post's if you are getting a panny. Two of those turned on a lathe with bolt down feet to the mantle would work great - Assuming the mantle is sound. If you have him make it as two parts it will be easier to center.


Bruce
 

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Discussion Starter · #19 ·
Thanks, but I already have the table stand and have measured the size and distance between the posts. I am not sure what you mean by two parts. If it turns out right, it will look a lot like the table stand, but with a base that is only 4 inches deep. I asked him to drill four holes in the base so that I can screw it directly into the mantle to prevent the dreaded slide.
 

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Oh! Ok- that's cool-


Making a new stand with a single base means you have to have the two posts spaced exactly apart (metric, BTW), to match up to the holes in the plasma. If it were made as two feet (bases or have some lateral adjustment) - then the centering on hole spacing is a moot point. That's all I meant. (Less chance for error).


If you already have the post's why not just re-use them, instead of making new ones? Or is that already the plan?


Bruce
 
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