I plan to mount our newly purchased TV on a wall bracket with an arm. The idea is that the arm should be fully extended when we watch TV and otherwise folded. Since we have lightweight concrete walls, I am a bit worried about how this will work.
The conditions are as follows: TV and soundbar weigh 25kg TV arm weighs 10kg
The arm length is 800mm and the wall plate is 480x288mm in size (see image).
Mounting will be done with three screws at the top (250mm to the bottom edge) and three at the bottom.
The pull load should, according to a hobby formula, be just under 100kg total or just over 30kg per mounting. The wall is made of lightweight concrete from 1950. Thickness is 250mm. The quality is supposed to be j=0.5 according to the building description. The drawing notes 0.6. I assume this is a measure of density.
So to my questions:
1. I am considering using lightweight concrete screws and not plugs. In that case, I would prefer to use Essve's lightweight concrete screws heavy loss 10.5x185 (should handle over 200kg), but they seem hard to find in a six-pack (30-pack costs over 500 SEK). It instead leans towards Byggmax 8x140 (should handle 150kg) or equivalent ordinary lightweight concrete screw in the largest possible dimension. Does this sound reasonable considering the loads and that the arm will be extended and retracted several times daily?
2. Is there any risk to the wall itself regarding the load and the coarse screws? The wall plate is not particularly large, and I'm worried about cracks (am I being overly paranoid?).
3. Should I just give in and put a 15mm plywood behind to spread the loads?
I have no experience with lättbetong, but I would try to attach something with a small screw and plug in a hidden spot.
Then break and bend a little to get a sense of what the wall can handle.
A thin metal sheet could be an alternative to plyfa. Maybe a bit easier to conceal if aesthetics are important.
I have set up some shelves and similar items. The material is porous, but not so sensitive that large chunks break off or that it creates cavities. What I'm mainly considering is how much I need to over-dimension because the arm will be folded in and out. It's hard to test that.
Good idea with the sheet metal. I'm also considering putting two flat irons vertically, about 800mm long, to distribute the loads. Just need to find someone who can weld and drill in metal.
I have mounted a row of overhead cabinets in the kitchen with Essve's lightweight concrete screws in a leca wall, and I think they hold really well as long as you don't let them "run empty" at all. That is, neither when inserting nor overtightening. Definitely superior to Bauhaus's own variant, where the thread has a much steeper pitch. Maybe Byggmax has one with a similar thread, then it might work just as well. I also used a board and plywood to distribute the load, mostly because it feels better and because I needed to build out a bit, though I really don't think it was necessary for the strength.
When I attach heavy machinery to aerated concrete, I use through-bolt and large washer on the backside.
Then we are up to about 100 kg in machine weight.
It would of course have been an idea. Unfortunately, it is an exterior wall on the second floor, so a bit impractical and not so aesthetically pleasing.
Have you ever experienced cracking when hanging up such heavy items?
Thanks! Then maybe I should just go with "regular" lightweight concrete screws. Hopefully, the screws will only loosen slightly before everything crashes to the ground if it turns out to be undersized.
So! Now the contraption is mounted on the wall. Amazon sent a 1200mm long arm instead of 800mm. However, it won't be extended all the way anyway, and I hope I have over-dimensioned.
I used three Sormat 8x130 lightweight concrete screws at the top and the same number at the bottom. Also placed two 8x65 at the top for some possibly unscientific reason. I compared Sormat with Essve in the store and couldn't see any difference. Sormat came in a 10-pack, so it was an easy choice.
I screwed slowly with firm pressure. Very little concrete dust came out, so it feels secure. Couldn't use the torque function on the screwdriver because it disengaged halfway, so I had to do it manually at the end.
Now there's only some cable work left.
Click here to reply
Vi vill skicka notiser för ämnen du bevakar och händelser som berör dig.
