The foundation consists of a concrete pad, for stability; a course of cinder block for elevation and heat buffer; and two courses of firebrick for further elevation and protection of the foundation.
The fireboxes are made up of a unique Detrick firebrick, designed for a hanging system. Cavities were filled with crushed IFB material.
The idea is two-fold, first to help protect the shelves from the dramatic temperature variation of the inner chamber and the fireboxes; and secondly, to help distribute weight evenly on these used and slightly damaged shelves.
Height of the fireboxes is at five courses to allow for a grate height of nine inches and plenty of room for a coal bed and adequate airflow.
The Interior, Showing one inlet and the Exit Flue
The flue is temporarily supported by two bricks while under construction.