Abstract: A folding joint mechanism for stackably collapsing elongated structural sections includes a plurality of substantially identical brackets pivotably interconnected and rotatable between an extended and a stowed configuration. In the extended configuration, the brackets abut each other against stop protrusions on the top outside surface of each bracket forming foldable extensions that are able to support significant weight by distributing the top-side force. In the stowed configuration, the brackets are compacted to a substantially stacked disposition whereby the brackets are aligned and directly adjacent to one another. The joint and bracket assemblies may be employed in elongated sections of various structures in which compactability may be advantageous for shipping, storage, and user transportation.