Filling space UNDER plasterboard

[Day]

I want to attach a pull up bar to a wall. It's a brick wall that had plasterboard attached to it rather than rendered. When I drill into the wall there is approximately 10mm gap of empty space between the plasterboard and the wall. I suspect that the plasterboard will crumble if the pull up bar places pressure on it. I was hoping that there might be a way of flowing something into the gap between the wall and plasterboard using some thin flexibile tube to give the plasterboard some support. Something similar to expanding foam but it would have to be hard and solid when set. Is there any products you can suggest? I think that filling thw space within a radius of 100mm from the drill hole should be sufficient. I do not need to fill the space over the whole wall.

 

[RandomGrinch]

Hi,

I'm sure you will get a range on answers here!
I'm just a DIY'er, so feel free to ignore! Personally, I would get a pull up bar, with a decent triangular frame, something like:

And then use a metal standoff collar (the depth of the plasterboard and any void), to transfer the compressive force (from the bottom fixings) to the bricks.

...as well as using some decent anchor bolts, or chemical fixings!

 

[Day]

My bar has approx 25cmx10cm metal plates that sit on the wall. Due to limited space the design you have shown will not fit. Even this one might break the plasterboard at the bottom fixing.

 

[RandomGrinch]

Sorry, I accidently posted, before I had finished editing - try a refresh!
I would use some standoff collars, something like:

There are 'Corefix' fasteners available, but I don't know how well they would take a compressive/bending force.

 

[Day]

I was considering something similar but actually cutting out the plasterboard same size as the metal plates of the pull up bar and puting in spacers made out of wood to sit flush with the plasterboard.

 

[Deleted member 292770]

I was considering something similar but actually cutting out the plasterboard same size as the metal plates of the pull up bar and puting in spacers made out of wood to sit flush with the plasterboard.

You said it.