Product Code Database
Roof tiles are overlapping tiles designed mainly to keep out precipitation such as rain or snow, and are traditionally made from locally available materials such as clay or slate. Later tiles have been made from materials such as concrete, glass, and plastic.
Roof tiles can be affixed by screws or nails, but in some cases historic designs utilize interlocking systems that are self-supporting. Tiles typically cover an underlayment system, which seals the roof against water intrusion.
These tiles commonly feature a squared base, as is the case with English people clay tiles, but in some cases can have a pointed or rounded end, as seen with the beaver-tail tile common in Southern Germany.
In early designs tegula were perfectly flat, however over time they were designed to have ridges along their edges to channel water away from the gaps between tiles.
Early examples of this profile were created by bending a piece of clay over a worker's thigh, which resulted in the semi-circular curve. This could add a taper to one end of the tile.
These tiles are traditionally formed through an extruder. In addition to the S-shaped Spanish tiles, this category includes the Scandia tiles common to Scandinavia and Northern Europe.
Unlike other types of tiles, which can in some cases be produced through a variety of methods, interlocking tiles can only be manufactured on a large scale with a machine press.
In many cases interlocking tile is designed to imitate other patterns of tile, such as flat shingles or pantiles, which can make it difficult to identify from the ground without inspecting an individual tile for a ridge.
The earliest roof tiles from the Archaic period in Greece are documented from a very restricted area around Corinth, where fired tiles began to replace thatched roofs at two temples of Apollo and Poseidon between 700 and 650 BC.Örjan Wikander, p. 285 Spreading rapidly, roof tiles were found within fifty years at many sites around the Eastern Mediterranean, including Mainland Greece, Western Asia Minor, and Southern and Central Italy.Örjan Wikander, p. 286 Early Greek roof-tiles were of the imbrex and tegula style. While more expensive and labour-intensive to produce than thatch, their introduction has been explained by their greatly enhanced fire-resistance which gave desired protection to the costly temples.Örjan Wikander, p. 289
The spread of the roof-tile technique has to be viewed in connection with the simultaneous rise of monumental architecture in Ancient Greece. Only the newly appearing stone walls, which were replacing the earlier mudbrick and wood walls, were strong enough to support the weight of a tiled roof.Marilyn Y. Goldberg, p. 309 As a side-effect, it has been assumed that the new stone and tile construction also ushered in the end of 'Chinese roof' ( Knickdach) construction in Greek architecture, as they made the need for an extended roof as rain protection for the mudbrick walls obsolete.Marilyn Y. Goldberg, p. 305
A Greek roof tile was responsible for the death of Molossian Greeks king Pyrrhus of Epirus in 272 BC after a woman threw one at the king's head as he was attacking her son.
Roman imbrex and tebula roofs generally avoided the use of nails and were instead held in place through gravity, it is possible that this was one of the reasons their tile was found on roof pitch.
The Romans spread the use and production of roofing tile across their colonies in Europe, with kilns and tile-works constructed as far west and north as Spain and Britain. Early records suggest that brick and tile-works were considered under the control of the Roman state for a period of time.
For a while after the dissolution of the Roman Empire, the manufacture of tile for roofs and decoration diminished in Northern Europe. In the twelfth century clay, slate, and stone roofing tile began to see more use, initially on abbeys and royal palaces. Their use was later encouraged within Medieval towns as a means of preventing the spread of fire. Simple flat shingle tiles became common during this period due to their ease of manufacture.
Scandinavian roof tiles have been seen on structures dating to the 1500s when city rulers in Holland required the use of fireproof materials. At the time, most houses were made of wood and had thatch roofing, which would often cause fires to spread quickly. To satisfy demand, many small roof-tile makers began to produce roof tiles by hand. The Scandinavian style of roof tile is a variation on the pantile which features a subdued "S" shape reminiscent of an ocean wave.
In Britain, tiles were also used to provide weather protection to the sides of timber frame buildings, a practice known as tile hanging. Another form of this is the so-called mathematical tile, which was hung on laths, nailed and then grouted. This form of tiling gives an imitation of brickwork and was developed to give the appearance of brick, but avoided the brick taxes of the 18th century.RW Brunskill, Illustrated Handbook of Vernacular Architecture (1970:58-61)
Chinese architecture is notable for its advancement of colored gloss glazes for roof tiles. Marco Polo made note of these on his travels to China, writing:
The roof is all ablaze with scarlet and green and blue and yellow and all the colors that are, so brilliantly varnished that it glitters like crystal and the color of it can be seen from far away.
Onigawara are most often found in Buddhist temples. In some cases the ogre's face may be missing." onigawara 鬼瓦." JAANUS. Retrieved on June 12, 2009.
The designs used on giwa can have symbolic meanings, with different figures representing concepts such as spirituality, longevity, happiness, and enlightenment. The five elements of fire, water, wood, metal and earth were common decorations during the Three Kingdoms period, and during the Goryeo dynasty Celadon glaze was invented and used for the roof tiles of the upper class.
Many post-war Korean roofs feature giwa and a common ornamental symbol is the Mugunghwa, South Korea's national flower.
Metal roof tiles made of gold, silver, bronze and copper are restricted to religious architecture in South Asia. A notable temple with golden roof tiles is the Nataraja temple of Chidambaram, where the roof of the main shrine in the inner courtyard has been laid with 21,600 golden tiles.
In Indonesia, approximately 90% of houses in Java island use clay roof tile. Traditionally, Javanese architecture use clay roof tiles. However, it was not until late 19th century that houses of commoners in Java and Bali started using roof tiles. The Dutch colonial administration encouraged the usage of roof tiles to increase hygiene. Before the mass usage of roof tiles in Java and Bali, commoners of both of islands used thatched or nipa roof like the inhabitants of other Indonesian islands.
In the Philippines, aside from various thatching methods, a native roof tiling technique is the kalaka which uses halved bamboo sections fitted together. During the Spanish colonial era of the Philippines, colonial-era bahay na bato architecture (which mixes native and Spanish architecture) also extensively used the Spanish-style Monk and Nun tiles, known natively as teja de curva.
Pieces of clay roof tile have been found in archeological excavations of the English settlement at Roanoke Colony dating to 1585, and in later English settlements in Jamestown, Virginia and St. Mary's, Maryland. Spanish and French colonists brought their designs and styles of roofing tile to areas they settled along what are now the southern United States and Mexico, with Spanish-influenced tile fragments found in Saint Augustine, Florida, and both Spanish and French styles used in New Orleans, Louisiana.
Dutch settlers first imported tile to their settlements in what are now the Northeastern United States, and had established full-scale production of roofing tiles in the upper Hudson River Valley by 1650 to supply New Amsterdam.
Clay roof tiles were first produced on the West Coast at the Mission San Antonio de Padua in 1780. This Spanish-influenced style of tile remains in common use in California.
One notable site of roof tile production was Zoar, Ohio, where a religious sect of German Zoarites formed a commune in 1817 and produced their own roofs in a handmade German beaver-tail style for several decades.
From the 1700s through early 1800s, clay roofing tile was a popular material in cities due to its fire-resistance, especially after the establishment of urban fire-codes.
In spite of improving manufacturing methods, clay tile fell out of favor within the United States around the 1820s, and cheaper alternatives such as wood shingle and slate tile became more common.
These conditions combined to bring a significant expansion in the use of roof tile, with a shift from regional and hand-produced tile to patented and machine-made tile sold by large-scale companies.
The Gilardonis' design marked a significant shift in the design of roofing tile. Prior to this tile most roofing tile profiles could be hand made without the need for large-scale machines, but the new interlocking tiles could only be produced with a tile press and were more cost effective than comparable vernacular styles. Through the rest of the 19th century many companies began refining and developing other versions of interlocking tiles.
The Gilardoni brothers began making their design in 1835 and took out a patent on their first design of interlocking clay tile in 1841, with a new design patented ten years later. The Gilardonis shared their patent with six other French tile manufacturers between 1845 and 1860, contributing greatly to the spread of interlocking tile usage throughout France and Europe. Their company built additional factories and continued to operate until 1974.
While the Martin Brothers invented the design, its widespread use was more due to the pattern's adoption and international production after its original patent expired. The Marseilles tile was widely exported, especially in European colonies in South America and Central America, Africa, and Australia.
French-manufactured Marseilles tiles were imported to Australia by 1886 and New Zealand by 1899. Many New Zealand railway stations were built with them, including Dunedin. Large scale production of Marseilles tiles by Wunderlich began in Australia during war-time import shortages in 1916. From 1920, factories at Pargny-sur-Saulx exported tiles to England. By 1929 Winstone were making them at Taumarunui, in a tile works established about 1910, which was replaced by Plimmerton in 1954.
Ludowici's design was mass produced in Germany and later the United States by the Ludowici Roof Tile company, who advertised the pattern as French tile.
Many tiles found in the Mangalore region of India are derived from or made in this pattern. Clay roof tiles had been produced in the region since missionary Georg Plebst set up the first factory at Mangalore, Karnataka, India, in 1860 after finding large deposits of clay by the banks of the Gurupura River and Netravati River rivers. The initial tiles they produced were similar to the Gilardoni brothers' design, but later tiles adopted Ludowici's pattern. Over the years ten companies produced Mangalore tiles, which were exported around the Indian Ocean and subcontinent.
Conosera was initially manufactured and sold by the Celadon Terra Cotta Company of Alfred, New York. After a merger formed the Ludowici-Celadon Company in 1906 the group continued to produce Conosera tile for special orders.
In order to reduce the high shipping cost for his tile, Kroher adopted a 'do-it-yourself' method of tile manufacture for some time, where he sold a supply of cement and the necessary tools for a home-builder to create their own tiles. This had the disadvantage that cement was prepared by amateurs and did not always have consistent or correct mixing preparation.
Concrete tiles became more widespread in Germany over the next few decades after manufacturers such as Jörgen Peter Jörgensen and Hartwig Hüser began producing interlocking and overlapping designs.
The concrete tile industry grew and spread internationally through the early 20th century, driven by its cheapness to produce at scale. Researchers considered concrete tile inferior to clay tile, largely due to its fundamental weaknesses of porosity and color impermanence.
It is uncommon for a roof to be completely covered in glass tiles however there are a few exceptions, such as on the tower of Seattle's King Street Station.
Plastic tiles are generally designed to imitate slate or clay tiles, and achieve their color through synthetic dyes added to the plastic. They are produced through injection molding.
In 2016 a collaboration between the companies SolarCity and Tesla Motors produced a hydrographically printed tile which appears to be a regular tile from street level but is transparent to sunlight when viewed straight on. Tesla later acquired SolarCity and the solar shingle product was described as "a flop" in 2019. The company later dropped their claim that their tiles were three times as strong as standard tiles, without specifying why they backed away from the claim.
The tiles which cover this section of the roof have to direct water away from the top of the ridge and onto either side of the pitched roof below.
They are commonly a fixture of Greek and Roman tile roofs and can often be highly ornamental.
A common effect seen in cement roof tiles is efflorescence, which is caused by the presence of free lime within concrete. This lime reacts with water to form calcium hydroxide, which creates a chalky deposit on the outside of the tiles. While not detrimental to the strength or durability of the cement tiles, this effect is considered unappealing.
Clay tile porosity can range greatly depending on quality of production, but some manufacturers can achieve less than 2% moisture absorption. Concrete roof tiles tend to feature around 13% moisture absorption, which requires periodic resealing every 3–7 years to avoid critical failure. The inherent porosity of cement requires that cement tiles are made very heavy and thick, as a result they have continuously been one of the heaviest roofing materials in the market.
It is commonly believed that a porous clay tile can be waterproofed through the application of a glaze; however studies have shown that this is not the case. If a clay body contains significant pores, water will permeate them over time regardless of exterior coating.
The breaking strength of plastic roof tiles varies greatly depending on temperature. Unlike ceramics or metals, plastics have glass transition temperatures that fall within the range of winter temperatures, often resulting in them becoming extremely brittle during colder periods.
Originally, most color variation on matte clay tiles was caused by variation in kiln firing temperature, kiln atmospheric conditions, and in some cases reductive firing. Many producers have shifted away from this process since low firing temperatures typically result in a higher porosity and lower breaking strength.
Engobes are now commonly used to replicate the appearance of historic firing variation, using a thin colored ceramic coating which chemically bonds to the tile to provide any range of matte colors to the fired tiles while allowing consistent firing conditions. Glazes are used when a shinier gloss appearance is desired. Like their clay base, both engobes and glazes are fully impervious to color fading regardless of UV exposure, which makes them unique among artificial colorants.
The color of slate tiles is a result of the amount and type of iron and organic material that are present, and most often ranges from light to dark gray. Some shades of slate used for roofing can be shades of green, red, black, purple, and brown.
Cement tiles typically are colored either through the use of a pigment added to the cement body, or through a concentrated slurry coat of cement-infused pigment on the outside of the tiles. Due to the simple production process and comparatively low firing temperature, cement tiles fade over time and often require painting to restore a "new" appearance.
Plastic tiles are colored through the incorporation of synthetic dyes added to them during molding. As a result of their reactive chemical composition they can suffer degradation from UV rays and fade after a few years of use.
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