A thermal insulating structural assembly and a method for forming a thermal insulating structural assembly includes longitudinally separating an elongated metallic support beam into a first portion and a second portion, mechanically coupling the first beam portion to the second beam portion with a plurality of clamp assemblies so that the first beam portion is spaced a predetermined non-zero distance from the second beam portion and is mechanically coupled to the second beam portion only by the clamp assemblies, and introducing between the beam portions, a low thermal-conductive material at least partially thermally insulating the first beam portion from the second beam portion.