Abstract: A method of forming a composite panel with a facade comprising a planar arrangement of thin discrete facers on a body of structural backing material. The method comprises the steps of providing a horizontal casting bed, providing a plurality of facers each with chamfers at corners between side-rear and end-rear walls, arranging the facers in abutting relationship atop the casting bed and in a selected pattern in a face down planar configuration so that the chamfers on the facers open upwardly and define narrow elongated sealant channels at joints between contiguous facers. Depositing a sealant in the channels and pouring concrete as a structural backing material atop the facers, the rear surfaces of the facers and the concrete adhering to form a composite panel.