The floor plan of my new apartment shows that there is a "reinforced TV wall" in the living room. The previous owner had mounted his TV on the wall using molly bolts. I removed the protruding part of them and pushed the rest into the wall, but before I patched over the holes, I noticed that there was a wooden board behind. From what I've read, you don't need more than wood screws to attach the TV wall mount when you have some kind of wooden board – I don't know if it's OBS or plywood – behind single plasterboard.
I haven't patched the holes yet, but what struck me was that the wooden board is not attached to the plaster wall – it doesn't feel anchored in any way, as I can poke it with a screwdriver and make it wobble back and forth, so to speak. There is a total length of about 6 cm from the hole to the wooden board if I press on the wooden board with a screwdriver until it stops and the board is leaning against the far wall, so it shouldn't be more than just screwing the TV mount with a screw that is 7–8 cm to ensure that it reaches the wooden board?
I haven't patched the holes yet, but what struck me was that the wooden board is not attached to the plaster wall – it doesn't feel anchored in any way, as I can poke it with a screwdriver and make it wobble back and forth, so to speak. There is a total length of about 6 cm from the hole to the wooden board if I press on the wooden board with a screwdriver until it stops and the board is leaning against the far wall, so it shouldn't be more than just screwing the TV mount with a screw that is 7–8 cm to ensure that it reaches the wooden board?
Now that it is open, try to measure where you have the board and write it down properly. Then screw the board in place with drywall screws into the drywall and patch it up. After the surface layer, you can mount your TV calmly with screws that fit the thickness of the bracket plus 30 mm.
Does the board really need to be attached to the plaster? It should be attached to the studs and should prevent the screws from being pulled out of the plaster, a bit like a very large molly... Try scanning the wall with a stud finder and you should be able to find the board, or make test holes with a thin drill and see where it hits resistance. You'll be spackling and creating a new surface anyway, so a few extra 3mm holes won't make much difference.
As the TS writes in the first post, the wooden board is not fastened behind the plaster but can be pushed towards the corresponding board on the other side of the wall - this means that the wooden board "only" distributes the force from the screws over a larger part of the plaster and (if it rests at the bottom of the hole) absorbs some horizontal forces. It does not have to be attached to the plaster but it helps if it is not pushed aside by the screws for the TV mount so that these just sit in the plaster.T toolman77 said:
You mean for the purpose of attaching the wooden board to the drywall, getting it closer to the wall BEFORE I screw in the wall bracket for the TV?L largab said:
Hmm, I'm not quite sure what you mean. I tried to measure as best as I could and found that it starts to take hold at 3 cm in. Since the drywall is 1.3 cm, the gap to the wooden board is about 2.7 cm. If I push until it stops, that is, until the wooden board hits the backing drywall, the total distance is 5.5 cm (a "gap" or empty space of 4.2 cm between the wall and the wooden board). How do you mean I should screw in the board with drywall screws?TomasJor said:
Exactly so. Excuse the amateur here, but isn't the wooden board attached to anything at all between the walls? Is it just a custom-sized board that stands "loose" on the floor?T Testarn said:
Is the solution to use sufficiently long screws to ensure they reach the wooden board?
As I understand it, the board stands on the floor between the gypsum boards.O oliverc said:
To easily mount the TV in the future, make sure to grab the board and pull it towards the wall and screw it in. No more gap.
Final result. 13mm gypsum, 11mm OSB, 30mm screws are needed and everything is stable.
I'm pondering a bit about how that would work. Drill a hole in the wooden board and then grab it with a hook-like object, pull it towards the wall and screw it in place in 2–3 different spots near the hole?
It's probably fine to drill a hole as you mentioned, or you can just start with a longer screw that attaches to the wooden board and then continue with regular drywall screws around where the TV mount will be placed.
Those screws are just meant to hold the wooden board against the drywall, no load there.
Those screws are just meant to hold the wooden board against the drywall, no load there.