The imbrex and tegula (plural imbrices and tegulae) were overlapping
roof tiles
Roof tiles are designed mainly to keep out rain, and are traditionally made from locally available materials such as terracotta or slate. Modern materials such as concrete, metal and plastic are also used and some clay tiles have a waterproof g ...
used in
ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
and
Roman architecture
Ancient Roman architecture adopted the external language of classical Greek architecture for the purposes of the ancient Romans, but was different from Greek buildings, becoming a new architectural style. The two styles are often considered o ...
as a waterproof and durable
roof covering
A roof ( : roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of te ...
. They were made predominantly of
fired clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay part ...
, but also sometimes of
marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorpho ...
,
bronze or
gilt. In Rome, they replaced
wooden shingles, and were used on almost every type of structure, from humble outbuildings to grand temples and public facilities.
The tegula (
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
solenes) was a plain flat tile, or a flat tile with raised edges, which was laid flat upon the roof, while the imbrex (Greek kalupter) was a semi-cylindrical roofing tile, like a half-pipe, laid over the joints between the tegulae. When well-made and properly imbricated (overlapped), there was little need for further waterproofing or
sealant
Sealant is a substance used to block the passage of fluids through openings in materials, a type of mechanical seal. In building construction ''sealant'' is sometimes synonymous with ''caulking'' and also serve the purposes of blocking dust, sou ...
.
The roofing area was generally surrounded by
antefix
An antefix (from Latin ', to fasten before) is a vertical block which terminates and conceals the covering tiles of a tiled roof (see imbrex and tegula, monk and nun). It also serves to protect the join from the elements. In grand buildings, t ...
ae, which were often decorated and had several decorative
anthemia to cover each end row imbrex.
The concept of imbrex and tegula roofing in
pitched roof
Roof pitch is the steepness of a roof expressed as a ratio of inch(es) rise per horizontal foot (or their metric equivalent), or as the angle in degrees its surface deviates from the horizontal. A flat roof has a pitch of zero in either insta ...
construction is still in use today as an international feature of style and design, and is the origin of the term
imbrication for the condition of things arranged in overlapping layers.
History and development

Imbrices and tegulae were first made by the
Greeks
The Greeks or Hellenes (; el, Έλληνες, ''Éllines'' ) are an ethnic group and nation indigenous to the Eastern Mediterranean and the Black Sea regions, namely Greece, Greek Cypriots, Cyprus, Greeks in Albania, Albania, Greeks in Italy, ...
. Like
bricks, they were formed of wet
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay part ...
in a four-sided
mould
A mold () or mould () is one of the structures certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. No ...
, often shaped with a piece of wire, and then baked in an oven or
kiln
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...
. More sophisticated moulds were developed over time.
Tegulae were originally made perfectly flat, or with nothing more than a ridge underneath the upper border, which allowed the tile to be "hung" upon a sloping roof so that it would not slide to the ground. Later, tegulae were formed with a raised border on the two vertical sides, which would channel rainwater to the bottom of the tile, rather than allowing it to seep between tiles to dampen the roofing materials. Another improvement occurred when these two raised borders were made to converge, forming a broad v-shaped
trapezoid
A quadrilateral with at least one pair of parallel sides is called a trapezoid () in American and Canadian English. In British and other forms of English, it is called a trapezium ().
A trapezoid is necessarily a convex quadrilateral in Eucli ...
with the narrowest edge downwards, nestling into the widest part of the tile below it to form a continuous channel.
The imbrices completed the
waterproofing
Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environme ...
of the roof by arching over the joints between the vertical edges of the tegulae, dividing the roof into channels. Rain water flowed off the curved imbrices into the channels and down over the surfaces of the tegulae, and descended into the
gutter (''canalis''). In formal architecture the ''canalis'' had a plain or ornamented frontal piece set atop the
entablature
An entablature (; nativization of Italian , from "in" and "table") is the superstructure of moldings and bands which lies horizontally above columns, resting on their capitals. Entablatures are major elements of classical architecture, and ...
, immediately above the
cornice
In architecture, a cornice (from the Italian ''cornice'' meaning "ledge") is generally any horizontal decorative moulding that crowns a building or furniture element—for example, the cornice over a door or window, around the top edge of a ...
. The semicircular opening at the front of the lowermost imbrex was often capped with an ornamental ''fronton'', and the spouts which drained the gutters were frequently decorated with
lion
The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'' native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphi ...
s' heads (''capita leonina'') or other fantastic or grotesque faces.
By Roman times many tiles were being made under the auspices of various
Roman legion
The Roman legion ( la, legiō, ) was the largest military unit of the Roman army, composed of 5,200 infantry and 300 equites (cavalry) in the period of the Roman Republic (509 BC–27 BC) and of 5,600 infantry and 200 auxilia in the period of t ...
s, and were imprinted with a stamp of the legion's insignia. Imbrices and tegulae are common finds in
archaeological site
An archaeological site is a place (or group of physical sites) in which evidence of past activity is preserved (either prehistoric or historic or contemporary), and which has been, or may be, investigated using the discipline of archaeology an ...
s, and their design and markings can be of use in dating the sites and identifying the inhabitants.
For instance, a 1993 archaeological dig in
Merseyside
Merseyside ( ) is a metropolitan and ceremonial county in North West England, with a population of 1.38 million. It encompasses both banks of the Mersey Estuary and comprises five metropolitan boroughs: Knowsley, St Helens, Sefton, Wirral ...
in England uncovered over of tile and
kiln
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...
remains. Some of the tegulae were stamped with the "LXXVV" insigniae of the
Legio XX Valeria Victrix
Legio XX Valeria Victrix, in English Twentieth Victorious Valeria Legion was a legion of the Imperial Roman army.
The origin of the Legion's name is unclear and there are various theories, but the legion may have gained its title ''Valeria ...
. Romans also often recycled broken tiles by incorporating them into
mortar.
Tiles of
marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorpho ...
were first used around the year
620 BC.
[ Pausanias, ''Description of Greece'']
v.10 §2
Besides the superior beauty and durability of the material, these tiles could be made of a much larger size than those of clay. Consequently, they were used in the construction of the greatest temples, such as the
Temple of Zeus at
Olympia,
the
Parthenon
The Parthenon (; grc, Παρθενών, , ; ell, Παρθενώνας, , ) is a former temple on the Athenian Acropolis, Greece, that was dedicated to the goddess Athena during the fifth century BC. Its decorative sculptures are conside ...
at
Athens
Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital city, capital and List of cities and towns in Greece, largest city of Greece. With a population close to four million, it is also the seventh List ...
, and the
Serapeum
A serapeum is a temple or other religious institution dedicated to the syncretic Greco-Egyptian deity Serapis, who combined aspects of Osiris and Apis in a humanized form that was accepted by the Ptolemaic Greeks of Alexandria. There were se ...
at
Puteoli
Pozzuoli (; ; ) is a city and ''comune'' of the Metropolitan City of Naples, in the Italian region of Campania. It is the main city of the Phlegrean Peninsula.
History
Pozzuoli began as the Greek colony of ''Dicaearchia'' ( el, Δικα ...
(modern Pozzuoli). Still more expensive and magnificent tiles were made of
bronze and
gilt.
Pliny the Elder
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic ...
's '' Natural History''
Book 33.3 §18
Gallery
File:Antefix, Nordisk familjebok.png, Diagram of roofing with antefixae
File:Feurs Musée Tegulae Imbrices.JPG, Gallo-Roman tegulae and imbrices - Museum of Feurs
Feurs (; frp, Fuèrs) is a commune in the department of Loire, Auvergne-Rhône-Alpes, France.
History
Antiquity
The city was founded by the Romans. The name Feurs is a contraction of ''Segusiavorum Forum''. With a forum the Gallo-Roman era, ...
(France)
File:Tiled imbrex and tegula roof in Hainan- 02.jpg, Imbrex and tegula style roof tiles are also used in other parts of the world. This is a roof in Hainan
Hainan (, ; ) is the smallest and southernmost province of the People's Republic of China (PRC), consisting of various islands in the South China Sea. , the largest and most populous island in China,The island of Taiwan, which is slight ...
, China, with concave tegula.
File:Parthenon from south.jpg, The Parthenon from the south. In the foreground of the image, a reconstruction of the marble imbrices and tegulae forming the roof is visible, resting on wooden supports.
See also
*
*
Notes
References
* (public domain text)
External links
* {{Commons category-inline, Imbrices and tegulae
Ancient Roman architectural elements
Ancient Greek architecture
Roof tiles
Archaeological artefact types
Ancient Roman pottery
Roofing materials