Post and lintel (also calledprop and lintel, atrabeated system, or atrilithic system) is a building system where strong horizontal elements are held up by strong vertical elements with large spaces between them. This is usually used to hold up a roof, creating a largely open space beneath, for whatever use the building is designed. The horizontal elements are called by a variety of names includinglintel, header,architrave orbeam, and the supporting vertical elements may be calledposts,columns, orpillars. The use of wider elements at the top of the post, calledcapitals, to help spread the load, is common to manyarchitectural traditions.
In architecture, a post-and-lintel or trabeated system refers to the use of horizontal stone beams orlintels which are borne bycolumns or posts. The name is from theLatintrabs,beam; influenced bytrabeatus, clothed in thetrabea, a ritual garment.
Post-and-lintel construction is one of four ancient structural methods of building, the others being thecorbel,arch-and-vault, andtruss.[1]
A noteworthy example of a trabeated system is inVolubilis, from theRoman era, where one side of theDecumanus Maximus is lined with trabeated elements, while the opposite side of the roadway is designed in arched style.[2]
The trabeated system is a fundamental principle ofNeolithic architecture,ancient Indian architecture,ancient Greek architecture andancient Egyptian architecture. Other trabeated styles are thePersian, Lycian,Japanese, traditionalChinese, andancient Chinese architecture, especially in northern China,[3] and nearly all theIndian styles.[4] The traditions are represented in North and Central America byMayan architecture, and in South America byInca architecture. In all or most of these traditions, certainly in Greece and India, the earliest versions developed using wood, which were later translated into stone for larger and grander buildings.[5]Timber framing, also usingtrusses, remains common for smaller buildings such as houses to the modern day.
There are two main forces acting upon the post and lintel system: weight carryingcompression at the joint between lintel and post, andtension induced by deformation of self-weight and the load above between the posts. The two posts are under compression from the weight of the lintel (or beam) above. The lintel will deform by sagging in the middle because the underside is under tension and the upper is under compression.
The biggest disadvantage to lintel construction is the limited weight that can be held up, and the resulting small distances required between the posts.Ancient Roman architecture's development of thearch allowed for much larger structures to be constructed. Thearcuated system spreads larger loads more effectively, and replaced the post-and-lintel system in most larger buildings and structures, until the introduction of steelgirder beams andsteel-reinforced concrete in the industrial era.
As with theRoman templeportico front and its descendants in laterclassical architecture, trabeated features were often retained in parts of buildings as an aesthetic choice. Theclassical orders of Greek origin were in particular retained in buildings designed to impress, even though they usually had little or no structural role.[6]
The flexural strength of a stone lintel can be dramatically increased with the use ofPost-tensioned stone.
