Wall mount 75" / 43kg TV

[diywedders]

Hi all,

Just looking for advice on hanging a new TV.

External wall, 1950's UK council build.

I currently have a 65" / 24kg mounted on this wall with a slim/flush mount.

I'm going to 75" / 43kg and would also like to move to a full motion mount like this to make the odd cable switch easier.

Not entirely sure the wall material, but I think concrete/some sort of block. This photo is the only exposed bit of wall I could think of from a cupboard in the next room!

I've read a lot of threads here and elsewhere but few deal with a TV of this size/weight!

--

Really just asking about fixings.

I've seen a lot of praise for Rigifix?

I'm also being paranoid (I think?) and thinking about resin anchors, but what I've seen suggests that's a step further than needed?

One last question: assuming the hole spacing is different on the new mount, how is best to fill the holes from the old mount?

Thanks

 

[johnny2007]

Anchors.
With that weight on a swinging arm you want to make sure you have a good grip on the wall.

 

[rsgaz]

How big are the holes in the wall bracket?

 

[Lucid]

Thanks for posting the photo. It looks like it shows concrete for the wall construction. I take it it's bare concrete in the cupboard but plastered over elsewhere? With concrete it's hard and produces grey dust when drilled. There may be steel reinforcing bars in a certain points. If it was brick then you'd get a red dust when the wall is drilled.

Any fixing is only as good as the material it's anchored within. If you were drilling into a brick wall, and you were lucky enough to hit the centre 1/3rd of each brick, then quite honestly you could use some brown wall plugs and screws and hang the new bracket off 8 of those and it would still be marginally overkill. Life being what it is though, you're quite likely to hit the the edge or the mortar between on some holes, and then the brick splits or you're at the mercy of whether the mortar is hard or crumbly. More fixing points increases your chances of getting some solid anchor points even if others are a bit crap.

With concrete walls then many of these issues go away. There are no traditional mortar joints. There are no brick edges. All you need then is something to fill the hole which provides a grippy interface between the screw (a wedge effectively) and the inner surface of the hole. Rigifix will do that, but they're not right for solid walls (brick / block / concrete with an over-skim of base and topcoat plaster). Where Rigifix comes into its own is with walls that have a surface finish that forms a hollow chamber. This is Dot-n-Dab A.K.A. drylining. You see, Rigix does for drylined walls what concrete- or steel-piling does for building on soft land. It take the weight off the soft surface layer and transfers the load to the more sold level deeper down.

You can see the Rigifix idea here. Now, if your home has solid walls but then a surface layer that is hollow because it's battens and then plasterboard on top if that then Rigifix is your baby. But if it's solid walls with plaster on top then not only will Rigifix be the wrong solution but they'll also be hard work to use. That's because part of the design is to have the post of the main anchor sticking out proud from the underlying wall surface. More than that, it's designed to stick out a long way; long enough to bridge the gap between that underlying wall and the air gap that drylining leaves. That's a long way. Where you have a solid wall then then you're going to end up with the bracket wall plate floating off the wall surface when there's no need.

Have a proper look at your wall to see what you're dealing with. If it's concrete with a layer of plaster on top then standard wall plugs will do just fine. Use grey wall plugs if you want to go larger. In concrete, each one will hold 65kg. For brick it's 30kg. You're going to use several.

 

[denso13]

Most likely concrete blocks, but either way, screws and wall plugs will be fine.

 

[diywedders]

Sorry for the lack of response but the TV is delayed in back order hell so I have been waiting for news...

I did buy the mount - it weighs 6.6kg on its own and I have no doubts about it holding this TV.

The included fixings for concrete/block/brick are M8 x 65 lag bolts and plastic anchors.

There's plenty of holes along the mount for more than 4 fixings though, so I would like to add some centrally too (plus one of the anchors was broken in the box so I 100% need to buy something!)

The included bolts do look substantial and I believe they can hold the weight, I just worry about pulling the thing out the wall when pulling out the TV?

I've been looking at various anchors and would sleeve anchors be suitable? 10mm hole with an M8 bolt, pretty confident the mount wont pull out the wall without pulling the wall down.

Thanks for posting the photo. It looks like it shows concrete for the wall construction. I take it it's bare concrete in the cupboard but plastered over elsewhere? With concrete it's hard and produces grey dust when drilled. There may be steel reinforcing bars in a certain points. If it was brick then you'd get a red dust when the wall is drilled.

...

Have a proper look at your wall to see what you're dealing with. If it's concrete with a layer of plaster on top then standard wall plugs will do just fine. Use grey wall plugs if you want to go larger. In concrete, each one will hold 65kg. For brick it's 30kg. You're going to use several.

Thanks for the long and detailed response!

I can confirm the walls are just plaster on to the conrete/block surface. I decorated the lounge and installed the current wall mount a few years ago and the walls are definitely a grey material.

I guess I was worried about it being aerated block and whether that would need any different treatment?

Once I have a date for the new TV arriving I will remove my current TV and mount and can look at the existing holes and confirm the material.

How big are the holes in the wall bracket?

They're ~8mm to match the included M8 bolts - here's a photo of the wall plate.

 

[rsgaz]

plus one of the anchors was broken in the box s

In which case, bin the lot, and the screws.

would sleeve anchors be suitable?

Yeah, they'd be fine. Just get branded ones, not Chinesium ones.

They're ~8mm to match the included M8 bolts

I personally would use Fischer S10 plugs (which are 50mm long) with about 70mm M8 coach screws (depends on your plaster depth).
Four along the top and just regular red plugs, washers and 2 inch screws at the bottom. You'll be able to swing from it.
The beauty of the s10 plugs, even if you are unfortunate enough to hit a mortar line, you can just go for it anyway, just insert the plugs so that they expand up and down.

 

[Brigadier]

I fitted very similar bracket to external wall at my old house by drilling (slightly downwards, to stop moisture tracking in) all the way through to the outside, and securing the bracket on threaded rods. Hefty washers and lock nuts on both ends.

 

[blup]

Fischer nylon plugs and spax screws. Ignore the depth of plaster when calculating how deep to drill.

Blup