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 fire would not probably affect the iron until the wooden beams were badly burned.” With the advent of high-strength engineered lumber, the advantages of flitch-beams disappeared. For example, comparing the capacity of 2 beams spanning 18 feet: Additionally, use of this type of beam has greatly declined due to the high cost of labor. Engineered lumber can be cut to length and installed much like sawn lumber; the flitch requires shop fabrication and/or field bolting. This, coupled with a much increased self-weight of the beam (11.4 pounds (5.2 kg) for engineered wood vs. 25.2 pounds (11.4 kg) for a flitch