Irrespective of the way beams are arranged, they create the coffered ceiling effect. But the waffle pattern is subject to the way beams crisscross..A coffer or coffering in architecture is a series of sunken panels in the shape of a square, rectangle, or octagon in a ceiling, soffit or vault. A series of these sunken panels was often used as decoration for a ceiling or a vault, also called caissons ‘boxes” , or lacunaria “spaces, openings” , so that a coffered ceiling can be called a .Want to live like a king? You sure can! The beauty of a room is the beauty of the coffered ceiling. Not only does it add warmth and comfort to a room, but it also makes a room look extravagant..What matters when you’re laying out a coffered ceiling is the size of the finished beam, not the size of the crown molding. And you have to use the Outside Dimension of the full finished beamthe O.D.not the backing or substrate you might be installing first. I make my coffered ceilings using .