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I'm struggling to mount my 31kg Panasonic TH-P60ST60A 60 inch TV to the wall in my apartment and was hoping someone here might be able to give me some advice.

The walls in my apartment seem to be a layer of drywall, about 20mm thick, followed by a 10mm gap, and then some type of brick. As far as I know, there are no studs in this wall (it's in Australia, and the walls here seem to be constructed quite differently from the walls I'm used to in Canada):

behind the wall

I used a hammer drill to put 8 holes in the wall, when I drilled through the drywall, it was pretty easy, but I had to switch to the hammer when I reached the brick (or whatever it is) behind the drywall, so it seemed somewhat solid, although definitely not as solid as the type of brick you'd find outside:

holes

I then used the following 8mm x 80mm plastic plugs

plugs

and tried to push them as far back as possible, to try to get them seated into the brick:

plugs in wall

Then I put the TV mount on the wall and tried fastening some large screws into the plastic plugs to secure it to the wall, although unfortunately what ended up happening is that the screw just twisted the plastic plug, and it eventually just broke off:

broken plug

Here's a picture of the wall with the mounting bracket waiting to be screwed in:

complete wall

You can see that there's a large gap in the wall, which the owners thought was a great idea, but I beg to differ. I was still able to drill 4 holes with 100mm spacing, which I figured should provide enough support (if I was able to get a solid bolt in the wall, that is)

So now I'm stuck. I have 8 ugly holes in my wall (actually, 9 because I drilled one too close to the corner and hit the metal bracket) and I haven't been able to attach a single screw.

I think there's two main issues so far:

  1. I used an 8mm drill bit for an 8mm plug, but the "brick/stone/whatever" behind the wall might have been too soft, in which case I may have made the hole too large, so the plugs are just rotating around not gripping
  2. Perhaps I didn't actually push the plug far enough into the wall so that it reached the brick, in which case when I twist the screw, it just shears off the top of the plug because it has nothing to grip on, however, I've pushed the plug pretty far into the wall, and it feels like it's seated in the brick, but I can't really tell for sure.

In any case I'm at a loss of what to do next. I'd like to avoid calling a professional, since they charge about $400 to mount a TV and was hoping I could do it myself, but now I'm stuck. If anyone has any suggestions of what to try next, please let me know! Thanks!

Edit: here are some additional pictures of the gap behind the wall:

wall1 wall2 wall3 wall4 wall5

And a close up of the screw inside the plastic plug:

bustedplug

And a google sketchup diagram of possibly using a wooden frame to support the TV:

woodenframe

Update May 25th 2017

Thanks to all those who answered, you gave me some great suggestions, and I'm happy to report that I've finally managed to mount the TV on the wall!

I took AndyT's advice and bought some larger 10mm plugs for my 8mm screws. While I was drilling the larger holes, it felt like I hit brick behind the wall, and the screws feel pretty sturdy, as does the bracket, so I think the TV should be secure.

Here's some pics of the bracket and TV now attached to the wall:

mounted1 mounted2 mounted3 mounted4

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If the top of the plug is shearing off when you put the bolt in, then this means the bottom of the plug isn't turning (so not a problem of the hole being too large), but the top of the plug is turning (which means the bolt is gripping it rather than turning within it).

Looking at the picture of your bolt in the partially failed plug, and given the above, I believe your plug diameter is too small for your bolt. Your options would therefore be to either get smaller bolts, or to get larger plugs (and drill a larger hole for them).


An alternative would be to get a different sort of plug. There is a product called "grip-it" designed to attach to plasterboard (=drywall) which has been installed dot-and-dab over masonry as per your situation. I've found it to work well, but the diameter of the fixing is very large, so is only suitable when the bolt won't be near to a visible edge. The business started in the UK, I have no idea whether it's available in Australia.

  • I think you're right about the plug being too small for the bolt. I've edited my post and attached a picture of the bolt in the plug. I know it's supposed to be a tight fit and should expand, but this looks to be too tight of a fit. The screw is an M8, which I'm assuming means 8mm, and the guy at the hardware store said that I should use 8mm plastic plugs, but I think he might have been mistaken. I think I'll see if I can find larger plugs and will drill a bigger hole. I've checked out "grip-it", it looks really interesting, the only downside being the size of the hole required. Thanks! – adamc Apr 27 '17 at 9:55
  • @adamc - An 8mm screw should go in a 10mm plug. See e.g. fischer spec. Your screw thread should not be up hard against the edge of the hole you drill - there should be plastic plug between the two. – AndyT Apr 27 '17 at 10:03
  • Thanks for the response Andy, I'll get some 10mm plugs and drill some bigger holes. If this doesn't work, then I may build a frame and place it in the gap behind the wall, as suggested by fixer1234 and shown in the diagram on my post. I'll update this post once I manage to get the TV on the wall. – adamc Apr 27 '17 at 10:14
  • I've now managed to attach the TV to the wall and have updated my original post with new pics. Thanks for your suggestions, it's now been 12 hours and the TV has stayed on the wall, so far so good! – adamc May 25 '17 at 21:03
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This is a challenging situation to support an expensive TV. I simply wouldn't trust anchors in brick of unknown quality and condition, especially with those working conditions and the leverage of a big gap between the anchor and the load.

It isn't clear if your last picture is of the same location. If it is, the opening behind the mount is almost certainly framed with lumber, and you could use lag bolts or heavy screws into those studs. I'll assume, though, that picture is just to illustrate the TV mount.

There are toggles of various designs for drywall that are rated for big loads. You can support almost anything with enough of them. But you have only a small gap behind the drywall, and I would be concerned about there being adequate space for the wings to properly deploy.

I would also be concerned about the structural strength of the drywall. It is normally fastened to periodic studs, even when the drywall is used like paneling, which serve to reinforce it. In this case, it looks like someone just wanted to hide the brick with a decorative sheet of drywall. A 10mm gap might just be something like a strip of plywood top and bottom to leave an air gap between the drywall and the brick.

If it were my TV, I would approach it a different way. I wouldn't rely on that wall to support the TV. I would mount it on something "structural" that is independent. Two approaches:

  • If that wall is fairly narrow, where the drywall is wrapping an old brick feature, there will likely be framing in the corners. If so, and assuming actual studs were used, you can fasten a horizontal board to those studs, running the whole width of the wall. Use one at the height of the top of the mount and one at the bottom. You can add a few drywall anchors to hold the boards tight against the wall in the middle and to counteract sagging. Paint the boards to match the wall and fasten the TV mount to the boards.
  • If that's not the case, fasten the TV mount to essentially freestanding poles. There are fancy poles designed for this purpose, but you can just use a couple of boards painted to blend in. The floor supports the weight. The boards are fastened to the wall or ceiling joists just to keep them upright and plumb.

    Instead of two independent boards, you can add top and bottom boards to create a rectangular box that fits tightly floor to ceiling. Then a few nails through the horizontal boards into the floor and ceiling will keep it from moving. When you leave, there will just be a few nail holes to fill.

  • The last picture is indeed the same location. I've edited my post and added more pictures to show the dimensions of the gap. So you're saying that there should definitely be wood on the edges? I drilled into the edge and there seemed to be just a thin sheet metal frame. Your suggestion of mounting it to something structural is good - I think I could buy some wood to build a rectangular frame and put it in the gap in the wall. I could nail it to the wood floor and screw it to the side of the wall in the gap. I've attached a mockup of how it would look, do you think this would support the tv? – adamc Apr 27 '17 at 10:10
  • That's a great idea, but I would tweak it a little. 1) If that opening is not framed with studs, I wouldn't trust the sides to hold anything. Make the box taller to reach the ceiling and then run a few nails into the ceiling to keep it upright. There wouldn't even be a need to nail it into the floor. That was mainly in case the frame got bumped sitting in the room. 2) As a free-standing unit, you could make the width correspond with mounting holes on the TV bracket, which might not be the case sizing it for the opening in the wall. (cont'd) – fixer1234 Apr 27 '17 at 17:13
  • Your sketch shows a horizontal piece, which I assume is the bracket. Put a plank there (if the bracket is too tall, use two boards). Secure the board(s) to your frame and then fasten the TV bracket to that. If you want something wider to fasten the horizontal board(s) to, you can screw a block of wood to each upright on the inside of the opening. Use pilot holes for all mounting screws (bracket to board(s) and board(s) to frame). (cont'd) – fixer1234 Apr 27 '17 at 17:20
  • It looks like there are convenient holes in the bracket that would correspond with the position of the uprights. You could use the bracket like a washer. Drill clearance holes in the horizontal board(s) and fasten those to the uprights through the bracket. Actually, if there are mounting holes in the bracket corresponding with the uprights, you don't really need the horizontal board. Just fasten into the uprights. – fixer1234 Apr 27 '17 at 17:20
  • I looked at your new pictures, and it looks like that opening doesn't go to the ceiling. If there is framing at the top of the opening, fasten your frame into that. If the top of the opening is just more "decorative" drywall, spread the stress around. Put a few nails into the top and two or three at intervals on each side towards the top. (cont'd) – fixer1234 Apr 27 '17 at 17:46

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