Which plugs and screws should I use for this?

[Jupiter01]

I have a wall with 25mm cellotex backed plasterboards dot and dabbed on to a wall constructed from concrete blocks. I want to hang a mirror on this. The mirror weighs 10kg.

I have seen the corefix screws but assume they are not necessary in my scenario. They also seem very pricey.

Thanks in advance.

 

[23vc]

Brown plugs into the block and decent length screws

 

[Jupiter01]

Out of interest, would the same advice apply to curtain poles being hung on the same surface?
Also, I assume the plugs can be slotted into a screw and hammered home from the hole in the plasterboard?

 

[phatboy]

Out of interest, would the same advice apply to curtain poles being hung on the same surface?
Also, I assume the plugs can be slotted into a screw and hammered home from the hole in the plasterboard?

Yes and yes.

Push plug flush with plasterboard, push screw in, hammer until fully into block, then remove screw, add rail or whatever, and screw back in but not too tight that the plasterboard is crushed

 

[^woody^]

Out of interest, would the same advice apply to curtain poles being hung on the same surface?
Also, I assume the plugs can be slotted into a screw and hammered home from the hole in the plasterboard?

No.

There will be some flex on the fitting as you pull the curtains, so what needs to happen is that there be something solid directly behind the board and not a void, otherwise the screw will move slightly over time and loosen at the plasterboard.

 

[Jupiter01]

Which method do you recommend @^woody^ ?

 

[23vc]

You’ve got 3 options-
1. Hack the plasterboard away and put something behind it
2. Fix a batten which will be visible
3. Get a decent fixing with a decent size screw and brown plug, and don’t swing off your curtain poles

 

[^woody^]

Ideally you may be able to fix through and existing dab of adhesive.

If its too much trouble to try and insert some adhesive or suchlike to fill the void and make the area solid, then a bigger fixing with a metal sleeve will work (but may be impractical for the pole bracket), or if you cut a bit of 15mm copper pipe, you can make a sleeve to go through the plasterboard and up to the wall, and when the screw is then tightened into the wall it will take a lot of the wobble out of the screw. Make sure the hole in the plasterboard is nice and tight though and the sleeve is exactly the depth between the plasterboard surface and the surface of the wall behind.

 

[Jupiter01]

Aren’t the Corefix screws designed for these situations?

Thanks for your suggestions

 

[noseall]

If its too much trouble to try and insert some adhesive or suchlike to fill the void and make the area solid,

Out of interest, would the same advice apply to curtain poles being hung on the same surface?
Also, I assume the plugs can be slotted into a screw and hammered home from the hole in the plasterboard?

Applying a decent quality adhesive to the contact surfaces is better. For example we add a few lines of adhesive to the backs of rad brackets, curtain battens etc, before screwing against the wall.

 

[Jupiter01]

UPDATE: I tried the method of drilling a hole through the insulated boards and then the concrete block. I then hammered a rawlplug home before screwing a 70mm screw into this. I found that the screw had some flex on the plaster end. Probably because I hammered a rawl plug through and the outer flange of his may have widened the hole.

I initially resorted to packing this by squeezing some bits of a cut rawlplug in this void:

I then cut the bottom of a second rawlplug and pushed this into the plasterboard. The screw went through this and then the rawlplug that was hammered home into the block. This provided a nice snug fit for the screw:

and my finished project:

Thanks for all the advice.