Tile

A tile is a manufactured piece of hard-wearing material such as ceramic, stone, metal, or even glass, generally used for covering roofs, floors, walls, showers, or other objects such as tabletops. Alternatively, tile can sometimes refer to similar units made from lightweight materials such as perlite, wood, and mineral wool, typically used for wall and ceiling applications. In another sense, a tile is a construction tile or similar object, such as rectangular counters used in playing games (see tile-based game). The word is derived from the French word tuile, which is, in turn, from the Latin word tegula, meaning a roof tile composed of fired clay.

Tiles are often used to form wall and floor coverings, and can range from simple square tiles to complex mosaics. Tiles are most often made of ceramic, typically glazed for internal uses and unglazed for roofing, but other materials are also commonly used, such as glass, cork, concrete and other composite materials, and stone. Tiling stone is typically marble, onyx, granite or slate. Thinner tiles can be used on walls than on floors, which require more durable surfaces that will resist impacts.

Ceramics for tiles

Ceramics for tiles include earthenware (terracotta), stoneware or porcelain. Stoneware is harder and more durable than earthenware, and so more suitable for floors, but there is a slight difference between porcelain and ceramic tiles. Terracotta is traditionally used for roof tiles, but other manufactured materials including types of concrete may now be used.

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 and plastic are also used and some clay tiles have a waterproof glaze. A large number of shapes (or "profiles") of roof tiles have evolved. These include:

• Flat tiles – the simplest type, which are laid in regular overlapping rows. An example of this is the clay-made "beaver-tail" tile (German Biberschwanz), common in Southern Germany. Flat roof tiles are usually made of clay but also may be made of stone, wood, plastic, concrete, or solar cells.
• Imbrex and tegula – an ancient Roman pattern of curved and flat tiles that make rain channels on a roof.
• Roman tiles – flat in the middle, with a concave curve at one end at a convex curve at the other, to allow interlocking.
• Pantiles – with an S-shaped profile, allowing adjacent tiles to interlock. These result in a ridged pattern resembling a ploughed field. An example of this is the "double Roman" tile, dating from the late 19th century in England and US.
• Mission or barrel tiles – semi-cylindrical tiles laid in alternating columns of convex and concave tiles. Originally they were made by forming clay around a curved surface, often a log or the maker's thigh. Today barrel tiles are mass-produced from clay, metal, concrete or plastic.
• Interlocking roof tiles – similar to pantiles with side and top locking to improve protection from water and wind.
• Antefixes – vertical blocks which terminate the covering tiles of a tiled roof.

Roof tiles are 'hung' from the framework of a roof by fixing them with nails. The tiles are usually hung in parallel rows, with each row overlapping the row below it to exclude rainwater and to cover the nails that hold the row below. There are also roof tiles for special positions, particularly where the planes of the several pitches meet. They include ridge, hip and valley tiles. These can either be bedded and pointed in cement mortar or mechanically fixed.

Similarly to roof tiling, tiling has been used to provide a protective weather envelope to the sides of timber frame buildings. These are hung on laths nailed to wall timbers, with tiles specially moulded to cover corners and jambs. Often these tiles are shaped at the exposed end to give a decorative effect. 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.^[1]

Slate roof tiles were traditional in some areas near sources of supply, and gave thin and light tiles when the slate was split into its natural layers. It is no longer a cheap material, however, and is now less common.

History

Fired roof tiles are found as early as the 3rd millennium BC in the Early Helladic House of the tiles in Lerna, Greece.^[2][3] Debris found at the site contained thousands of terracotta tiles having fallen from the roof.^[4] In the Mycenaean period, roofs tiles are documented for Gla and Midea.^[5]

The earliest finds of roof tiles in archaic 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.^[6] Spreading rapidly, roof tiles were within fifty years in evidence for a large number of sites around the Eastern Mediterranean, including Mainland Greece, Western Asia Minor, and Southern and Central Italy.^[7] Early roof tiles showed an S-shape, with the pan and cover tile forming one piece. They were rather bulky affairs, weighing around 30 kg (66 lb) apiece.^[8] Being 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.^[9]

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.^[10] 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.^[11]

Production of dutch roof tiles started in the 14th century when city rulers 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 quickly spread. To satisfy demand, many small roof tile makers began to produce roof tiles by hand. Many of these small factories were built near rivers where there was a ready source of clay and cheap transport.

Floor tiles

These are commonly made of ceramic or stone, although recent technological advances have resulted in rubber or glass tiles for floors as well. Ceramic tiles may be painted and glazed. Small mosaic tiles may be laid in various patterns. Floor tiles are typically set into mortar consisting of sand, cement and often a latex additive for extra adhesion. The spaces between the tiles are nowadays filled with sanded or unsanded floor grout, but traditionally mortar was used.

Natural stone tiles can be beautiful but as a natural product they are less uniform in color and pattern, and require more planning for use and installation. Mass-produced stone tiles are uniform in width and length. Granite or marble tiles are sawn on both sides and then polished or finished on the top surface so that they have a uniform thickness. Other natural stone tiles such as slate are typically "riven" (split) on the top surface so that the thickness of the tile varies slightly from one spot on the tile to another and from one tile to another. Variations in tile thickness can be handled by adjusting the amount of mortar under each part of the tile, by using wide grout lines that "ramp" between different thicknesses, or by using a cold chisel to knock off high spots.

Some stone tiles such as polished granite, marble, and travertine are very slippery when wet. Stone tiles with a riven (split) surface such as slate or with a sawn and then sandblasted or honed surface will be more slip-resistant. Ceramic tiles for use in wet areas can be made more slip-resistant either by using very small tiles so that the grout lines acts as grooves or by imprinting a contour pattern onto the face of the tile.

The hardness of natural stone tiles varies such that some of the softer stone (e.g. limestone) tiles are not suitable for very heavy-traffic floor areas. On the other hand, ceramic tiles typically have a glazed upper surface and when that becomes scratched or pitted the floor looks worn, whereas the same amount of wear on natural stone tiles will not show, or will be less noticeable.

Natural stone tiles can be stained by spilled liquids; they must be sealed and periodically resealed with a sealant in contrast to ceramic tiles which only need their grout lines sealed. However, because of the complex, nonrepeating patterns in natural stone, small amounts of dirt on many natural stone floor tiles do not show.

The tendency of floor tiles to stain depends not only on a sealant being applied, and periodically reapplied, but also on their porosity or how porous the stone is. Slate is an example of a less porous stone while limestone is an example of a more porous stone. Different granites and marbles have different porosities with the less porous ones being more valued and more expensive.

Most vendors of stone tiles emphasize that there will be variation in color and pattern from one batch of tiles to another of the same description and variation within the same batch. Stone floor tiles tend to be heavier than ceramic tiles and somewhat more prone to breakage during shipment.

Rubber floor tiles have a variety of uses, both in residential and commercial settings. They are especially useful in situations where it is desired to have high-traction floors or protection for an easily breakable floor. Some common uses include flooring of garage, workshops, patios, swimming pool decks, sport courts, gyms, and dance floors.

Plastic floor tiles including interlocking floor tiles that can be installed without adhesive or glue are a recent innovation and are suitable for areas subject to heavy traffic, wet areas and floors that are subject to movement, damp or contamination from oil, grease or other substances that may prevent adhesion to the substrate. Common uses include old factory floors, garages, gyms and sports complexes, schools and shops.

Decorative tilework and colored brick

Decorative tilework should be distinguished from mosaic, where forms are made of great numbers of tiny irregularly positioned tesserae in a single color, usually of glass or sometimes ceramic.

The earliest evidence of glazed brick is the discovery of glazed bricks in the Elamite Temple at Chogha Zanbil, dated to the 13th century BC. Glazed and colored bricks were used to make low reliefs in Ancient Mesopotamia, most famously the Ishtar Gate of Babylon (ca. 575 BC), now partly reconstructed in Berlin, with sections elsewhere. Mesopotamian craftsmen were imported for the palaces of the Persian Empire such as Persepolis.

Tiling was widespread in the time of the Sinhalese kings of ancient Sri Lanka, using smoothed and polished stone laid on floors and in swimming pools. Historians consider the techniques and tools for tiling as well advanced, evidenced by the fine workmanship and close fit of the tiles. Tiling from this period can be seen Ruwanwelisaya and Kuttam Pokuna in the city of Anuradhapura.

Islamic tiles

Early Islamic mosaics in Persia consist mainly of geometric decorations in mosques and mausoleums, made of glazed brick. Typical turquoise tiling becomes popular in 10th-11th century and is used mostly for Kufic inscriptions on mosque walls. Seyed Mosque in Isfahan (1122 AD), Dome of Maraqeh (1147 AD) and the Jame Mosque of Gonabad (1212 AD) are among the finest examples.^[12] The dome of Jame' Atiq Mosque of Qazvin is also dated to this period.

The golden age of Persian tilework began during the reign the Timurid Empire. Single color tiles were cut into small pieces and assembled by pouring liquid plaster between them. After hardening, these panels were assembled on the walls of buildings. But the mosaic was not limited to flat areas. Jame Mosque in Yazd (1324-1365 AD) and Goharshad Mosque (1418 AD) are prominent examples of brick and tile mosaics of interiors and external surfaces of domes.^[12] Islamic buildings in Bukhara (16th-17th century) also exhibit very sophisticated floral ornaments.

Mihrabs, being focus points of mosques, were usually the places where most sophisticated tilework was placed. The 14th century mihrab at Madrasa Imami in Isfahan is an outstanding example of aesthetic union between the Islamic calligrapher's art and abstract ornament. The pointed arch, framing the mihrab's niche, bears an inscription in Kufic script used in 9th-century Qur'an.^[13]

One of the best known architectural masterpieces of Iran is the Shah Mosque in Isfahan, from the 17th century. Its dome is a prime example of tile mosaic and its winter praying hall houses one of the finest ensembles of cuerda seca tiles in the world. Wide variety of tiles had to be manufactured in order to cover complex forms of the hall with consistent mosaic patterns. The result was a technological triumph as well as a dazzling display of abstract ornament.^[13]

During the Safavid period mosaic ornaments were often replaced by a haft rang (seven colors) technique. Pictures were painted on plain rectangle tiles, glazed and fired afterwards. Besides economic reasons, the seven colors method gave more freedom to artists and was less time-consuming. It was popular until Qajar period when the palette of colors was extended by yellow and orange.^[12]

The Persianate tradition continued and spread to much of the Islamic world, notably the İznik pottery of Turkey under the Ottoman Empire in the 16th and 17th centuries. Palaces, public buildings, mosques and türbe mausoleums were heavily decorated with large brightly colored patterns, typically with floral motifs, and friezes of astonishing complexity, including floral motifs and calligraphy as well as geometric patterns.

The zellige tradition of Arabic North Africa uses small colored tiles of various shapes to make very complex geometric patterns. It is halfway to mosaic, but as the different shapes must be fitted precisely together, falls under tiling.

Western tilework

Medieval Europe made considerable use of painted tiles, sometimes producing very elaborate schemes, of which few have survived. Religious and secular stories were depicted. The imaginary tiles with Old testament scenes shown on the floor in Jan van Eyck's 1434 Annunciation in Washington are an example. The 14th century "Tring tiles" in the British Museum show childhood scenes from the Life of Christ, possibly for a wall rather than a floor,^[14] while their 13th century "Chertsey Tiles", though from an abbey, show scenes of Richard the Lionheart battling with Saladin in very high-quality work.^[15] Medieval letter tiles were used to create Christian inscriptions on church floors.

Transmitted via Islamic Spain, a new tradition of azulejos developed in Spain and especially Portugal, which by the Baroque period produced extremely large painted scenes on tiles, usually in blue and white, for walls rather than floors. Delftware wall tiles, typically with a painted design covering only one (rather small) blue and white tile, were ubiquitous in Holland and widely exported over Northern Europe from the 16th century on, replacing many local industries. Several 18th century royal palaces had porcelain rooms with the walls entirely covered in porcelain in tiles or panels. Surviving examples include ones at Capodimonte, Naples, the Royal Palace of Madrid and the nearby Royal Palace of Aranjuez.

There are several other types of traditional tiles that remain in manufacture, for example the small, almost mosaic, brightly colored zellige tiles of Morocco and the surrounding countries. With exceptions, notably the Porcelain Tower of Nanjing, decorated tiles or glazed bricks do not feature largely in East Asian ceramics.

The Victorian period saw a great revival in tilework, largely as part of the Gothic Revival, but also the Arts and Crafts Movement. Patterned tiles, or tiles making up patterns, were now mass-produced by machine and reliably level for floors and cheap to produce, especially for churches, schools and public buildings, but also for domestic hallways and bathrooms. For many uses the tougher encaustic tile was used. Wall tiles in various styles also revived; the rise of the bathroom contributing greatly to this, as well as greater appreciation of the benefit of hygiene in kitchens. William De Morgan was the leading English designer working in tiles, strongly influenced by Islamic designs.

Since the Victorian period tiles have remained standard for kitchens and bathrooms, and many types of public area. Portugal and São Luís continue their tradition of azulejo tilework today. Notable among American tilemakers of the 1920s and 1930s were Ernest A. Batchelder and Pewabic Pottery.

Pebble tile

Similar to mosaics or other patterned tiles, pebble tiles are tiles made up of small pebbles attached to a backing. The tile is generally designed in an interlocking pattern so that final installations fit of multiple tiles fit together to have a seamless appearance. A relatively new tile design, pebble tiles were originally developed in Indonesia using pebbles found in various locations in the country. Today, pebble tiles feature all types of stones and pebbles from around the world.

Ceiling tiles

Ceiling tiles are lightweight tiles used inside buildings. They are placed in an aluminium grid; they provide little thermal insulation but are generally designed to improve the acoustics of a room. Mineral fiber tiles are fabricated from a range of products; wet felt tiles can be manufactured from perlite, mineral wool, and fibers from recycled paper; stonewool tiles are created by combining molten stone and binders which is then spun to create the tile; gypsum tiles are based on the soft mineral and then finished with vinyl, paper or a decorative face.

Ceiling tiles very often have patterns on the front face; these are there in most circumstances to aid with the tiles ability to improve acoustics.

Ceiling tiles also provide a barrier to the spread of smoke and fire. Breaking, displacing, or removing ceiling tiles enables hot gases and smoke from a fire to rise and accumulate above detectors and sprinklers. Doing so delays their activation, enabling fires to grow more rapidly.^[16]

Ceiling tiles, especially in old Mediterranean houses were made of terracotta and were placed on top of the wooden ceiling beams and upon those were placed the roof tiles. They were then plastered or painted, but nowadays are usually left bare for decorative purposes.

Modern-day tile ceilings may be flush mounted (nail up or glue up) or installed as dropped ceilings.

Digital printed tiles

Printing techniques and digital manipulation of art and photography are used in what is known as "custom tile printing". Dye sublimation printers, inkjet printers and ceramic inks and toners permit printing on a variety of tile types yielding photographic-quality reproduction.^[17] Using digital image capture via scanning or digital cameras, bitmap/raster images can be prepared in photo editing software programs. Specialized custom-tile printing techniques permit transfer under heat and pressure or the use of high temperature kilns to fuse the picture to the tile substrate. This has become a method of producing custom tile murals for kitchens, showers, and commercial decoration in restaurants, hotels, and corporate lobbies.

Diamond etched tiles

A method for custom tile printing involving a diamond-tipped drill controlled by a computer. Compared with the laser engravings, diamond etching is in almost every circumstance more permanent.

Mathematics of tiling

Certain shapes of tiles, most obviously rectangles, can be replicated to cover a surface with no gaps. These shapes are said to tessellate (from the Latin tessella, 'tile') and such a tiling is called a tessellation.

Further reading

• Carboni, S. & Masuya, T. (1993). Persian tiles. New York: The Metropolitan Museum of Art. 
• Marilyn Y. Goldberg, “Greek Temples and Chinese Roofs,” American Journal of Archaeology, Vol. 87, No. 3. (Jul., 1983), pp. 305–310
• Örjan Wikander, “Archaic Roof Tiles the First Generations,” Hesperia, Vol. 59, No. 1. (Jan.–Mar., 1990), pp. 285–290
• William Rostoker; Elizabeth Gebhard, “The Reproduction of Rooftiles for the Archaic Temple of Poseidon at Isthmia, Greece,” Journal of Field Archaeology, Vol. 8, No. 2. (Summer, 1981), pp. 211–227
• Michel Kornmann and CTTB, "Clay bricks and roof tiles, manufacturing and properties", Soc. Industrie Minerale, Paris (2007) ISBN 2-9517765-6-X
• E-book on the The Manufacture of Roofing Tiles in the United States from 1910.

See also

Wikimedia Commons has media related to Tiles.

• Building integrated photovoltaics
• Dimension stone
• Dropped Ceiling
• Glass tile
• Marble
• Porcelain tile
• Quarry tile
• Roof shingle
• Tile mural
• Vitrified tile
• Faux ceiling tiles

References

Look up tile in Wiktionary, the free dictionary.