I want to glue some foiled polystyrene insulation panels behind the radiators. The instructions recommend a "non solvent-based adhesive suitable for polystyrene". Would PVA do the trick? If so, I can avoid buying other glues. It looks like the wall is just painted, with no wallpaper (in some places, it was wallpapered first for some reason). I wont be able to clean the surface that well but I can fit a feather duster back there to clear the majority of the dust.