Flitch beam wooden beams, and have been largely supplanted by more recent technology. “Flitch” originally referred to a slab of bacon, which was cut into strips lengthwise. Similarly, a wooden beam was flitched by cutting it lengthwise; one half was then rotated 180 degrees both longitudinally and laterally to ensure that any defects were separated. In the 18 century, before the availability of steel beams, pine beams were flitched with hardwood such as oak. With the availability of affordable steel, flitch beams became a way to strengthen long-span wooden beams cost-effectively while taking up less space than solid wood. An 1883 article
Flitch beam from "The American Architect and Building News" compares three alternatives in a hypothetical railway station “in which the second story is devoted to offices, and where we must use girders to support the second floor of 25-foot span, and not less than 12 feet on centres if we can avoid it. This would give us to be supported by the girder a floor area of 12’ x 25’ = 300 square feet” and 31,500 pounds of load. After performing calculations the beams compare as follows: The article also cites the fire-retardant character of the flitch beam, “in case of a