Hanging 20kg projector in single drywall ceiling, with Molly

[Tekniker]

Is this a dumb idea?

The conditions are 13mm gypsum.
Projector 20kg
Ceiling mount 3kg

The projector mount is quite small but has holes for 4 screws in a round diameter of 130mm. See attached image.

If we consider using molly on these 4 holes, is it too tight for the gypsum to hold? Or what is the load capacity?

I can probably position the projector slightly to the side and get two of the holes in a beam. But I'm still curious about what to expect.

Plan C is to screw up a large plate (like MDF) that is screwed into the beams, and then mount the projector mount on this plate.

 

[Alikzus]

I wouldn't have dared. In general, I prefer duck feet (or variations of it) over molly plugs.

 

[datja]

But the ceiling plaster must be attached to something more solid inside that can be screwed into, right?

 

[Pjosk75]

Hello

Yes, I think it's a stupid idea.

You hardly want there to be even a small risk that things weighing 25 kg suddenly fall down.
Depending on what is above the drywall, I would make an opening in the drywall to attach more studs to the sides or even better a spacer upwards if there is more durable material in the ceiling.

 

[Tekniker]

I wouldn't have dared. Generally speaking, I prefer ankfötter (or variations of it) over molly plugs.

Don't know what ankfötter are. Can't find it on Google either 😅

 

[Tekniker]

Hi

Yes, I think it's a bad idea.

Items weighing 25 kg, you hardly want there to be even a small risk of them suddenly falling down.
Depending on what's above the plasterboard, I would make an opening in the plasterboard to be able to attach more studs to the sides or, even better, a spacer upwards if there's more durable material in the ceiling.

No, and here the question is how much plasterboard can withstand. I have no clue.

I'll take a closer look at the ceiling.

 

[datja]

To answer the question: do not hang heavy objects on drywall.

 

[Pjosk75]

What I find is that 1 square meter of plasterboard can withstand 15 kg. But this seems to apply to walls, so the tensile strength in a plaster ceiling is likely lower.

So you need to screw a board that's about 1.5 square meters if the mount is only attached to the single plasterboard.

 

[KalleKe]

15kg per m2 https://www.rapid.com//sv-se/guider...allexpander-fungerar-och-hur-du-anvander-dem/

 

[RiKr]

Attaching 25kg to the ceiling and getting some screws into the stud/support is completely fine.

 

[Tekniker]

What I find is that 1 square meter of plasterboard can hold 15 kg. But this seems to apply to walls, so the tensile strength in a plaster ceiling is probably lower.

So, you need to screw a board that is about 1.5 square meters if the mount is only attached to single plasterboard.

Have found a joist so two of the screws should be able to go into that, so two can be Molly.

 

[Alikzus]

Don't know what ankfötter are. Can't find it on Google either 😅

Essve Duckfoot

Fischer has something similar too, which I bought at Byggmax, but can't find it now.

Edit: https://www.byggmax.se/skivinfastning-fischer-duotec-246731

 

[Pjosk75]

Do you have any idea what kind of studs the plasterboard is attached to and how these are in turn attached upwards?

I might sound pessimistic, but I would never hang up 25 kg without knowing what the screws are anchored in. Partially because what you plan to hang is likely expensive, but mainly because a person or pet could be injured if the projector falls down.

 

[datja]

Found a beam, so two of the printers should be able to run on that, making two of them Molly.

I would never have done that. What is the cc for the beams in the ceiling?

Can't you open a small hatch and see what it looks like inside? Maybe you can put up a couple of short boards resting on the sparse paneling (if the ceiling is built like that)?

 

[Tekniker]

Essve Duckfoot

Fischer has something similar too, which I bought at Byggmax, but can't find it now.

Edit: [link]

Aha, I know those. Didn't know they were better than molly?