Mounting ceiling lamp gypsum.

[Crayo]

Hello
I am going to install a ceiling light. I think it weighs around 3-4kg. Gypsum ceiling, it's going to be over a table, so unfortunately, it will miss the joist between the short planks.
I'm thinking of using Molly, but is there any difference between the ones from Byggmax at 5 SEK each and the Essve ones at 30-50 SEK each?
There are 4 screw holes on the bracket. 20cm apart lengthwise and 4-5cm in width. I guess that placing 2 so close together would weaken the gypsum more than they would support?

 

[Johan Gunverth]

Molly that is properly mounted is always good. What does the ceiling mount of the fixture look like? What does the ceiling outlet look like?

 

[Crayo]

Molly that is properly mounted is always good. What does the fixture's ceiling mount look like? What does the ceiling outlet look like?

That's what the mount looks like, the outlet is a bit away so unfortunately there will be a cable running.

 

[Johan Gunverth]

6 mm short Molly will be perfect. I assume it's single plasterboard in the ceiling?

 

[Crayo]

6 mm short Molly will be just fine. I assume it's single plaster in the ceiling?

I don't know if it's single plaster, how common is double plaster in ceilings from the early 90s? 2 or 4 Molly?

 

[Johan Gunverth]

I don't know if it's single gypsum, how common is double gypsum in ceilings from the early 90s? 2 or 4 Molly?

Four Molly considering the holes are located in the corners.
You'll likely see when you have drilled the holes (since you already know where the mount should be) whether it's single or double. I believe it's primarily in newer multi-family houses where they want to reduce footstep noise better than with single gypsum, that they install double. In a private villa, it's probably not relevant.