A Lally column is a round or square thin-walled

structural steel Structural steel is a category of steel used for making construction materials in a variety of shapes. Many structural steel shapes take the form of an elongated beam having a profile of a specific cross section. Structural steel shapes, siz ...

column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member ...

filled with concrete and oriented vertically to provide support to beams or timbers stretching over long spans.Lally columns are an engineered Component and as such must be installed exactly as the design engineer specified.

Fabrication

The steel shell of a Lally column is filled with

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most ...

, which carries a share of the compression load, and helps prevent local buckling of the shell. The advantage of a Lally column over conventional structural steel is the ability to cut it to length on a construction site with simple hand tools such as a plumber's

pipe cutter A pipecutter is a type of tool used by plumbers to cut pipe. Besides producing a clean cut, the tool is often a faster, cleaner, and more convenient way of cutting pipe than using a hacksaw, although this depends on the metal of the pipe. There ...

or a

reciprocating saw A reciprocating saw is a type of machine-powered saw in which the cutting action is achieved through a push-and-pull ("reciprocating") motion of the blade. The original trade name Sawzall is often used in the United States, where Milwaukee Elec ...

. Lally columns are generally not as strong or durable as conventional structural steel columns. The term "lally column" is sometimes incorrectly used in reference to other types of

prefabricated Prefabrication is the practice of assembling components of a structure in a factory or other manufacturing site, and transporting complete assemblies or sub-assemblies to the construction site where the structure is to be located. The term is u ...

steel columns.

Invention

The Lally column is named after a U.S. inventor, John Lally, who owned a construction company that started production of these columns in the late 19th century. He resided in

Waltham, Massachusetts Waltham ( ) is a city in Middlesex County, Massachusetts, United States, and was an early center for the labor movement as well as a major contributor to the American Industrial Revolution. The original home of the Boston Manufacturing Company, ...

and

Boston Boston (), officially the City of Boston, is the capital city, state capital and List of municipalities in Massachusetts, most populous city of the Commonwealth (U.S. state), Commonwealth of Massachusetts, as well as the cultural and financ ...

during the period 1898–1907. He was issued four U.S.

Patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling disclo ...

s on composite columns: #614729, #869869, #901453, and #905888. Pat. #869869 was assigned to the U.S. Column Company of

Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. As part of the Greater Boston, Boston metropolitan area, the cities population of the 2020 United States Census, 2020 U.S. census was 118,403, making it the fourth most ...

Design development

Early Lally columns were made with structural steel, "standard" pipes, with wall thicknesses slightly less than 1/4". Modern Lally columns are typically made with 16 ga. (approx. 0.06") shells. Modern Lallies are therefore much lower in strength than the older ones (typically less than half the strength), and are also much more subject to damage by corrosion in moist environments. Modern Lally columns are primarily intended as somewhat stronger and more durable substitutes for wood posts in light-frame wood construction, although they are sometimes also used with steel beams.

References

1 Adjustable Steel Columns, October home inspections

External links

Examples of Uses

History of inventor John Lally

Home Inspection maintenance
Structural engineering Structural steel {{architecture-stub