expanding foam to plug a large hole?

sallyrsm

I've got a hole in the wall at the side of my chimney breast where the old back boiler was removed and up to now it's got a piece of hardboard over it and wallpapered over. Obviously you can see the outline of the hardboard..
Until now it's been fine but I've treated myself to some new Harlequin paper and I'd like the wall to be flush again.
Would expanding foam in the hole, sawed flush and then skimmed over work? I can do a little plastering myself if it's being papered over. I am guessing the void is about half a cubic metre..
Can anyone with a little knowledge let me know if that sounds feasible please? Other than that I'm going to have to put plasterboard over the void going right up to the ceiling which would mean redoing the coving a bit etc...
any ideas would be gratefully received... the void isn't in plasterboard, it's in a cinderblock wall.

diable

Brick it up and then skim it.

27col

I did actually do this to block up a hole in my bathroom where a toilet soil pipe had been moved. It seemed to work OK, but I did not bother to skim it, as the new position of the bath covered it.

tony6403

I imagine that the hole is something like 900mm x 600mm or similar.
If it is fairly straight along all of its sides , you could attach 50mm x 25mm wooden battens to the inside of the hole set back to allow for the thickness of your chosen plasterboard + 2/3mm skim.
Fix the battens by drilling and plugging and then nail or screw the plasterboard to the battens. Then plaster.

27col

I didn't notice that the hole was so large. Obviously I would not use the foam for a hole that size.