Editing Ancient Roman architecture (section)

=== Roman roofs ===
{{further|List of ancient Greek and Roman roofs}}
[[File:Temple of echo Baiae.JPG|thumb|upright|Inside the "Temple of Mercury" at [[Baiae]], a [[Frigidarium|swimming pool]] for a [[Roman bath]], dating to the late [[Roman Republic]],<ref>"[https://www.britannica.com/topic/Temple-of-Mercury Baiae, historic site, Italy]". ''[[Encyclopedia Britannica]]''. Accessed 6 June 2021.</ref> and containing one of the [[List of Roman domes|largest domes]] in the world before the building of the [[Pantheon, Rome|Pantheon]]]]

In [[Magna Graecia]] truss roofs presumably appeared as early as 550 BC.{{sfn|Hodge|1960|pp=38–44}} Their potential was fully realized in the Roman period, which saw trussed roofs over 30 meters wide spanning the rectangular spaces of monumental public buildings such as [[Roman temple|temples]], [[basilica]]s, and later churches. Such spans were three times as wide as the widest prop-and-lintel roofs and only surpassed by the largest [[List of Roman domes|Roman domes]].{{sfn|Ulrich|2007|pp=148f.}}

The largest [[truss roof]] by span of ancient Rome covered the [[Flavian Palace|Aula Regia]] (throne room) built for emperor [[Domitian]] (81–96&nbsp;AD) on the [[Palatine Hill]], Rome. The timber truss roof had a width of 31.67&nbsp;m, slightly surpassing the postulated limit of 30&nbsp;m for Roman roof constructions. Tie-beam trusses allowed for much larger spans than the older prop-and-lintel system and even concrete vaulting. Nine out of the ten largest rectangular spaces in Roman architecture were bridged this way, the only exception being the groin vaulted [[Basilica of Maxentius]].{{sfn|Ulrich|2007|pp=148f.}}