The back bedroom of my Victorian house has 2 cold exterior walls. They were plastered 20 years ago and the plaster is good. I want to insulate them by fixing polystyrene backed plasterboard to the walls, (40mm boards) then replaster.
I've read about glueing boards to the wall with plasterboard adhesive but can I use this method on the polystyrene backing? Is the plasterboard and polystyrene fixed firmly together or is there a danger that the plasterboard could come away? Would I need to use some sort of fixing screws as well?
If the plaster is good, you can dot'n'dab them. But i'd be concerned that you are avoiding the real issue, is the wall cold or damp or both? Because if there's damp there, you will only be covering it up and not resolving your problem and it will come back and haunt you! and your wall adhesive would not perform too well either!
But if it is just cold through lack of wall insulation it should remedy that, but you can get grants for having cavity wall insulation installed, just a thought!
Best of Luck
Thanks for the information. There is no damp on the walls at all and the plaster and paintwork is good. I could just repaint but to perform simple insulation may improve the warmth of my coldest room. A few years back I insulated the room above this one but screwed plasterboard to battens on brickwork. It worked very well. With this latest job I want a good finish but not create extra work for myself.
Just to be sure then, I dot'n'dab plasterboard adhesive directly on the polystyene/walls. No screws are needed. The plasterboard is firmly bonded to the polystyrene and is not likely to peel away.
Thanks for the advice. I'm more than able to do a good job, I just lack the technical knowledge. I think this website is excellent!!