Glue The Polystyrene Plate on a Pre -degree and Cleaned Surface of the Surface. Any Nitro. The Coated Surface Must Fourst Be Covered with A Penetrating Primer, Otherwide the Polystyrene Will Not Grassp The Ceiling Poorly. An Ordinary Pva is Suitable as an adesesive. You Need to Start Gluing the Plates from the Middle of the Room.