A method and apparatus to produce starter strips and decorative mouldings that are widely used in the construction industry. The method is a sequence of advancing a core, constructed from pre-formed expanded polystyrene (EPS), in a straight horizontal plane through a coating chamber with constraining devices preventing lateral and vertical movement. The coating chamber is filled with a thick liquid stucco or plaster or cement-like mixture and imparts a layer of the liquid onto the preformed core. The thickness of the coating is controlled with templates having an opening correspondingly larger than the core size and with the desired profile. The apparatus can be configured to coat a portion of an elongate surface in the case of producing a starter strip. In the case of a decorative moulding, the coating application can be limited to the exposed decorative surfaces only. The templates are designed to be interchangeable with other coating apparatus to produce starter strips, decorative mouldings, wall panel sections and columns commonly used in the construction industry.