Can old wallpaper jobs just be pasted over?
No, you can never just paste, or paint for that matter, over anything. The removal of old wallcoverings is necessary before any new application. So get into it, remove the old wallcovering, clean the walls with a mild detergent solution or adhesive remover, rinse with clear water and allow the surface to dry then apply a wallpaper sizing. However, if it is not possible to remove the old wallpaper, you still have to make sure the old wallpaper is secure and stable, sand the seams, then prime with an oil-base primer to completely seal the surface and then apply sizing to the walls before applying your new wallcovering.
