Mounting a heavy light

[SecretPrawn]

Hi,

I'm looking to install a heavy (about 4kg) light to replace some old ones in our living room. The original one was just mounted on the plasterboard.

I'm not confident that this will support the light, so want to mount it into the beam above the plasterboard ceiling.

This is however 85mm above the plasterboard ceiling.

Does anyone have any advice on what my best option for doing this would be? A straightforward long screw, or is there a better solution for securing it?

Thanks for any thoughts and advice.

Tom

 

[foxhole]

So what's holding the plasterboard up?

 

[SecretPrawn]

So what's holding the plasterboard up?

the only joist I can see through the 5cm hole around the light cable is 9 cm high. Without ripping any holes in the ceiling, I can’t get at any others - so I’m a bit fixed by where the cable is.

 

[foxhole]

Original fitting would normally be adjacent the nearest timber. Stick you finger in and you should be able to touch one.?
What fixing does the new light use?