In the case in water -based paint, you will have to spend more efforts to remove the old layer. To facilitate the process, experts advise to remove only peeling places with a spatula, expand cracks by any sharp object. You can also use the folk method, stick the old newspapers on the ceiling, and when the glue dries, when removing newspapers, the old paint will come with them. Either another option, moisten the old coating with a damp roller, and then repeat the action after 15 — 20 minutes, after all this you need to create an air flow directed to the ceiling, this can be done using a fan, the old paint is weathered and swollen, after which it is ease. can be removed with a spatula.