Anchor into wood

Accomodation, House and Garden
1
I need to mount something heavy to the ceiling and unfortunately discovered that the ceiling is a false ceiling with the only suitable mounting point being a sturdy chunk of wood about 50cm higher up.

My idea was to screw in some kind of anchor into the wood that a long threaded rod could be screwed into and then the object attached to the rod with a bolt.

Is this a sound idea and if so, any idea where to buy the anchor/rod and what it is called in German?

2
Not a straightforward task, normally you would use distance screws (schrauben) with a 8mm or 10mm thread on the part away from the wood but 500mm long is a bit too far.

https://www.opo.ch/de/distanz-und-ra...-05?position=7

What I would do in this situation is weld a 6 or 8mm woodscrew (or coach bolt) to a piece of 6 or 8mm threaded rod, so basically make your own. Alternatively, if you can predrill a hole about 1.5mm smaller than the threaded rod then use an angle grinder with a cutting wheel to shape the end of the rod similar to a "tap" used for making threads in metal. As long as you can get it started you should be able to thread it in 100mm or so and it will hold.

3
I found threaded rods for sale, but didn't yet find an appropriate anchor for it to be screwed into: https://www.jumbo.ch/de/gewindestang...37?sku=1062904

4
I guess you want something like this. There are few variations of these available.

https://www.galaxus.ch/de/s4/product...duebel-8400496

https://www.galaxus.ch/de/s4/product...uebel-13362447

https://www.galaxus.ch/de/s4/product...duebel-7327918

5
unfortunately, i have no equipment to do welding and not sure my first welding job should be for a bodge job to safely hold 35kg of lights 2m above my head!

6
Do you have any top or side access on the piece of wood you want to anchor to?

7
In a house we owned sone years ago we wanted to install ceiling fans on the ceiling of the top floors. The ceiling was sloped with wood beams.

We called a local carpenter as there was no way we wanted to attempt this ourselves and risk something falling on our heads! I think that is your safest bet here.

8
I installed a ceiling fan in the ceiling of my bedroom a few years ago. It was attached to one of the roof beams, and anchored using chain wrapped around the beam. No way could it fall.

9

1. Do you plan to open the ceiling to get the access to that 50cm higher positioned chunk of wood?

2. Or do you plan to to just make a small hole and than screw in the rod?

In first case you can use any kind of profile / flat iron / chain / wood that can carry the necessary weight.

In second case: thread rods normally have metal thread not one for wood, you would need to get some special piece somewhere

10
This kind of setup?

[](https://ibb.co/MNVbkBq)

11
Get a standing ceiling fan. Then attach a single wax candle on top of the fan. Turn the fan on and the wind will scatter the light rays all over the room to make it a super bright room

[](https://imgbb.com/)

12
What size of access hole do you have? is it small for just the wires or something like a screwed rod?

If it was a little bigger a crazy idea could be to glue a 50cm long piece of wood to become flush with the ceiling and fix to that... If there was a decent surface area for the glue.

It's a purely tensile load, a piece of 4x4 cm would probably hold a couple of hundred kilos..

Would you trust it though..

13
What sort of ceiling lamp weighs 32Kg?

What exactly are you planning to do in your house? Is this some kind of hobby or something more sinister?

14
Could potentially access the side, but not the top.

15
open the ceiling as I'm not sure doing it blind would be a good idea.

i decided in the end to get a flat piece of metal which i will drill a hole in and attach the threaded rod through the hole with a nut. i can then route out a space in the wood so that the metal sits flush and can be secured into the wood with screws.

16
Sounds like a plan, but consider coachbolts, then you can use a socket and ratchet.

If you have side access, you could alternatively drill a whole sideways through the beam, then another vertically to intersect, push the long threaded bar up through the vertical hole and thread it into a washer/nut pushed in from the side. A more complicated solution than what you propose though.

17
something like this:

18
Ach, so much bad advice. The standard solution to fasten threaded rod into wood is either a threaded insert (sometimes called threaded insert nut, or threaded wood insert nut), which you often find in flat-packed furniture (Einschraubmutter in German), or a dowel screw (Stockschraube in German). They look like this:

Threaded inserts:

Dowel screw:

In order to connect a threded rod to the fastener you use a regular long nut/extension nut (Verlängerungsmutter in German).

32kg may sound like a lot to us, but the design pull-out capacity of a screw into good wood is significantly higher. Plus a lamp is a static load. You can calculate a screw into wood withdrawal force here: https://www.engineeringtoolbox.com/w...ad-d_1815.html

19
Thanks. The insert/dowel screw was precisely what I was after (both were available at the local jumbo - unfortunately, I couldn't find the extension nut there.

20
i actually did lookup the holding force for screws and was surprised by the large static loads they could handle. i still added a safety cable just in case...