A Lally column is a round, steel support column filled with concrete, designed to provide vertical load-bearing support for beams and joists in building structures. Introduced as a fire-resistant support in 1898 and named after its inventor, John Lally, this column combines the compressive strength of steel with the mass of concrete to carry substantial weight, making it a reliable choice for both temporary shoring and permanent installations in residential and commercial construction.
In practical terms, Lally columns are typically installed beneath floor beams in basements, crawl spaces, or garages to prevent sagging and maintain structural integrity. In residential settings, they often support the main floor framing above basements, while in commercial projects, they can shore up mezzanines or lightweight roof assemblies. Unlike adjustable steel post jacks, Lally columns come in fixed lengths and rely on precise sizing during the installation process. Their concrete core also resists buckling more effectively than hollow steel posts, although they must be cut to exact height and set on a firm footing to perform as intended.