Lintel

A lintel or lintol is a type of beam (a horizontal structural element) that spans openings such as portals, doors, windows and fireplaces. It can be a decorative architectural element, or a combined ornamented/structural item. In the case of windows, the bottom span is referred to as a sill, but, unlike a lintel, does not serve to bear a load to ensure the integrity of the wall. Modern-day lintels may be made using prestressed concrete and are also referred to as beams in beam-and-block slabs or as ribs in rib-and-block slabs. These prestressed concrete lintels and blocks can serve as components that are packed together and propped to form a suspended-floor concrete slab.

An arch functions as a curved lintel.^[1]^[2]

^ Owen, Robert Dale (1849). "Concerning the two great divisions of manner in architecture". Hints on Public Architecture: Containing, Among Other Illustrations, Views and Plans of the Smithsonian Institution. Smithsonian Institution. Publication. New York: G.P. Putnam. p. 25. ISBN 9781404746824. Retrieved 4 March 2023. [...] at last [...] it occurred to some philosopher or mechanic [...] that by arranging small wedge-shaped stones or other materials in a semicircular form, a sort of curved lintel could be obtained, which, though composed of many distinct parts, could be stretched from pier to pier, or from pillar to pillar [...]. [...] There have been, in some stone constructions, what may be regarded as intermediate steps between the lintel and the arch.
^ Curley, Robert, ed. (1 October 2009). "Building Construction and Civil Engineering". The Britannica Guide to Inventions That Changed the Modern World. Turning Points in History. New York: Britannica Educational Publishing. p. 194. ISBN 9781615300648. Retrieved 4 March 2023. The arch can be called a curved lintel.

[1] Owen, Robert Dale (1849). "Concerning the two great divisions of manner in architecture". Hints on Public Architecture: Containing, Among Other Illustrations, Views and Plans of the Smithsonian Institution. Smithsonian Institution. Publication. New York: G.P. Putnam. p. 25. ISBN 9781404746824. Retrieved 4 March 2023. [...] at last [...] it occurred to some philosopher or mechanic [...] that by arranging small wedge-shaped stones or other materials in a semicircular form, a sort of curved lintel could be obtained, which, though composed of many distinct parts, could be stretched from pier to pier, or from pillar to pillar [...]. [...] There have been, in some stone constructions, what may be regarded as intermediate steps between the lintel and the arch.

[2] Curley, Robert, ed. (1 October 2009). "Building Construction and Civil Engineering". The Britannica Guide to Inventions That Changed the Modern World. Turning Points in History. New York: Britannica Educational Publishing. p. 194. ISBN 9781615300648. Retrieved 4 March 2023. The arch can be called a curved lintel.

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