Fastening in "flat wall"

[bjorsi]

Hello.
I live in a BRF built between 1959-1960. I have checked the drawings and there are different wall materials here and there.
I plan to hang the TV on the wall (19kg), and according to the drawings, the wall I plan to hang it on is a "flat wall".
From what I've read on the forum, it's some type of light concrete foundation. I've also tested drilling with a drill-screwdriver, which went without any problems.
Now to the question: which plug should I use?
I have looked at Essve's universal plug or their light concrete plug.
I was thinking of using their universal plug 8x50, 4 or 6 pieces. These are supposed to have a tensile load of 20kg per plug with screws in single drywall, which should be comparable to a light concrete foundation?

https://www.essve.se/wcsstore/CAS/PIM/ESSVE/docs/875669.pdf

 

[justusandersson]

Plattvägg usually means aerated concrete element. I think you should use an aerated concrete anchor and regular wood screws. The most important load will be shear stress on the screw, but in this case, it is negligible. If you buy screws that are strong enough to fit the TV mount, you don't need to think any more about it. The anchors are probably not available with less depth than 50 mm.

 

[justusandersson]

Plank wall usually means lightweight concrete elements. Use lightweight concrete plugs and wood screws of sufficient size to fit the TV bracket. The load is negligible compared to the screws and plugs available.

 

[bjorsi]

Thanks for the tip.
Chose to go with Essves universal plug 8x50 with accompanying screw. I'm thinking that 6 or 8 attachment points will be good, then you have plenty of margin.

https://www.essve.se/essvese/sv/pro...gg/universalplugg/skruv-med-universalplugg-46

 

[richardtenggren]

You're guaranteed to manage with one screw, but go for four

 

[bjorsi]

You will definitely manage with one screw, but go for four

4 might be enough? I've never attached such heavy objects to this material before.

 

[bjorsi]

Nice that when unpacking the wall mount, Samsung included fixings for different materials. Among others, Hilti's universal anchor with screw. Worth the trip to the hardware store to buy Essve's plug and screw. It should also work in lightweight concrete. https://www.hilti.se/c/CLS_FASTENER...00c3&salespackquantity=200 st&itemCode=315939

 

[richardtenggren]

As justus writes, the load in your case is negligible. If you simplify the screw to a rod (disregarding the threads) of 4 mm, it can handle approximately 200 kg before it shears off.

 

[bjorsi]

As justus writes, the load in your case is negligible; if you simplify the screw to a rod (ignoring the threads) of 4 mm, it can withstand approximately 200 kg before it shears off.

So in plain English: "4 attachment points are enough, if you want to be extra sure, go with 6"

 

[richardtenggren]

Yes, exactly like that, but essentially an anchor point, although it's always good to have at least two to prevent rotation.

 

[StrigErik]

The possibility that, for example, a 4mm screw under high load would shear off is unlikely. Instead, the plastic plug or both the plastic plug and the hole in the aerated concrete would deform, causing the screw and plug to be pulled out at a downward angle. However, more shear force than that from a 19kg load is likely needed.

 

[richardtenggren]

Absolutely, the hole is likely what limits in this particular case, as deformation of the plug would hardly affect it. But I don't have any material data on his wall.

 

[bjorsi]

The wall wasn't that terribly porous after all. Had to hammer in the plug even though I drilled with the correct drill diameter. Now the bracket is up.