A method and apparatus to impart a coating layer on the surface of decorative mouldings that are widely used in the externally insulated finishing systems (EIFS) in the construction industry. The method is a sequence of mechanically advancing a core, constructed from pre-formed expanded polystyrene (EPS, in a straight horizontal plane through a coating chamber/hopper with templates conforming to the desired decorative profile. The apparatus is a rectangular box with a funneled opening at the top with adjustable internal plates to direct the material from the sides of the box toward the pre-formed core that is being coated. Two plates on the bottom of the box support the pre-formed core and are adjustable to leave an opening in the center so that excess material can fall through the bottom after coating the last core. The templates are designed to be interchangeable with other coating apparatus designed by the inventor to produce start strips, decorative mouldings, wall panel sections and columns commonly used in the construction industry.