Tile

Mission, or barrel, roof tiles

A tile is a manufactured piece of hard-wearing material such as ceramic, clay, stone, porcelain or even glass. Tiles are generally used for covering roofs, floors, and walls, or other objects such as tabletops. The word is derived from the French word tuile, which is, in turn, from the Latin word tegula, meaning a roof tile composed of baked clay. Less precisely, the modern term can refer to any sort of construction tile or similar object, such as rectangular counters used in playing games (see tile-based game).

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 from ceramic, with a hard glaze finish, but other materials are also commonly used, such as glass, slate, and reformed ceramic slurry, which is cast in a mould and fired.


Roof tiles

Fancy Japanese roof tiles The largest (6000 m²)
wooden shingle roof
in Europe: Zakopane, Poland

Roof tiles are designed mainly to keep out rain, and are traditionally made from locally available materials such as clay, slate, or wood (wooden tiles are called shingles). Modern materials such as concrete and plastic are also used. Some clay tiles have a waterproof glaze.

Because of their long history, 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. This profile is suitable for stone and wooden tiles, and most recently, solar cells.
  • 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.
  • Mission or barrel tiles are semi-cylindrical tiles made by forming clay around a log and laid in alternating columns of convex and concave tiles.

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.

Floor tiles

6"x6" porcelain floor tiles

These are commonly made of ceramic, clay, porcelain or stone. Clay 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 oftentimes a latex additive for extra strength. The spaces between the tiles are nowadays filled with sanded or unsanded floor grout, but traditionally mortar was used.

See Laying tile

Wall tiles

Tilework on the wall of the Bond Street tube station

While ancient Roman building bricks were broader and thinner than modern ones and are therefore usually called tiles, the term wall tile is normally applied to finishing tiles. These are usually ceramic, but other materials such as mirrored glass or polished metal can be used. Wall tiles are usually glazed, and are often patterned by painting or embossing. Pictorial tiles, consisting of many tiles that the installer assembles like a jigsaw puzzle to form a single large picture, are available.

Modern wall tiles are fixed to a wall using a synthetic bonding agent tile adhesive for dry areas, or a cement-based mortar for areas prone to moisture, such as bath or shower walls. The spaces between the tiles are filled with a fine cement called unsanded grout. The excess grout is scraped off with a hard rubber block called a float immediately after applying; further, the grout is wiped again with a moist sponge before it completely hardens. The sponging provides added moisture to strengthen the grout as it cures. Finally, a cloth is rubbed over the wall tile to remove any haze which may remain from residual grout.

Decorative tilework

Ancient mosaic in the British Museum. Typical tilework on buildings in Santarém, Portugal.

Decorative tilework typically takes the form of mosaic upon the walls, floor, or ceiling of a building. Although decorative tilework was known and extensively practiced in the ancient world (as evidenced in the magnificent mosaics of Pompeii and Herculaneum), it perhaps reached its greatest expression during the Islamic period.

Some places, notably Portugal, have a tradition of tilework on buildings that continues today.

In the United States, decorative tiles were in vogue, especially in southern California, in the 1920s and 1930s. Prominent among art tile makers during this period was Ernest A. Batchelder.

Islamic tilework

Tilework of Hazrat Masoumeh shrine, Qom. First constructed in the late 8th century.

Perhaps because of the tenets of Moslem law (sharia) which disavow religious icons and images in favor of more abstract and universal representations of the divine, many consider decorative tilework to have reached a pinnacle of expression and detail during the Islamic period. Palaces, public buildings, and mosques were heavily decorated with dense, often massive mosaics and friezes of astonishing complexity. As both the influence and the extent of Islam spread during the Middle Ages this artistic tradition was carried along, finding expression from the gardens and courtyards of Málaga in Moorish Spain to the mosaics of the Hagia Sophia in Constantinople.

The 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 tessera, 'tile'). For detailed information on tilings see the tessellation page.

History of tiles

Tiles were developed as a product of earthenware pottery, either as an alternative use for fragments of broken pottery (called potsherds) or as an independent invention. Tiles have been used in construction for at least 4000 years, by the Romans, Greeks, Babylonians, Phoenicians and many other cultures.


This page about Tile includes information from a Wikipedia article.
Additional articles about Tile
News stories about Tile
External links for Tile
Videos for Tile
Wikis about Tile
Discussion Groups about Tile
Blogs about Tile
Images of Tile

Tiles have been used in construction for at least 4000 years, by the Romans, Greeks, Babylonians, Phoenicians and many other cultures. The incidence of twinning among cattle is about 1-4%, and research is underway to improve the odds of twinning, which can be more profitable for the breeder if complications can be sidestepped or managed. Tiles were developed as a product of earthenware pottery, either as an alternative use for fragments of broken pottery (called potsherds) or as an independent invention. Multiple births are common in many animal species, such as cats, sheep, and ferrets. For detailed information on tilings see the tessellation page. In this case, although the twins did come from the same egg, it is incorrect to refer to them as genetically identical, since they have different karyotypes. These shapes are said to tessellate (from the Latin tessera, 'tile'). When monozygotic twins are born with different genders it is because of chromosomal birth defects.

Certain shapes of tiles, most obviously rectangles, can be replicated to cover a surface with no gaps. The probability of this is so vanishingly small (only 3 documented cases) that multiples having different genders is universally accepted as a sound basis for a clinical determination that in utero multiples are not monozygotic. As both the influence and the extent of Islam spread during the Middle Ages this artistic tradition was carried along, finding expression from the gardens and courtyards of Málaga in Moorish Spain to the mosaics of the Hagia Sophia in Constantinople. Among monozygotic twins, in extremely rare cases, twins have been born with opposite sexes (one male, one female). Palaces, public buildings, and mosques were heavily decorated with dense, often massive mosaics and friezes of astonishing complexity. One 1992 study estimates that the frequency of heteropaternal superfecundation among dizygotic twins whose parents were involved in paternity suits was approximately 2.4%; see the references section, below, for more details. Perhaps because of the tenets of Moslem law (sharia) which disavow religious icons and images in favor of more abstract and universal representations of the divine, many consider decorative tilework to have reached a pinnacle of expression and detail during the Islamic period. This can lead to the possibility of a woman carrying fraternal twins with different fathers (that is, half-siblings).

Batchelder. Among fraternal twins, in rare cases, the eggs are fertilised at different times with two or more acts of sexual intercourse, either within one menstrual cycle (superfecundation) or, even more rarely, later on in the pregnancy (superfetation). Prominent among art tile makers during this period was Ernest A. There are some patterns of twinning that are exceedingly rare: while they have been reported to happen, they are so unusual that most obstetricians or midwives may go their entire careers without encountering a single case. In the United States, decorative tiles were in vogue, especially in southern California, in the 1920s and 1930s. Twins that have been separated early in life and raised in separate households are especially sought-after for these studies, which have been invaluable in the exploration of human nature. Some places, notably Portugal, have a tradition of tilework on buildings that continues today. Twin studies are studies that assess identical (monozygotic) twins for medical, genetic, or psychological characteristics to try to isolate genetic influence from environmental influence.

Although decorative tilework was known and extensively practiced in the ancient world (as evidenced in the magnificent mosaics of Pompeii and Herculaneum), it perhaps reached its greatest expression during the Islamic period. Many fertility treatments have no effect on the likelihood of multiple births. Decorative tilework typically takes the form of mosaic upon the walls, floor, or ceiling of a building. Some other treatments such as the drug Clomid can stimulate a woman to release multiple eggs, allowing the possibility of multiples. Finally, a cloth is rubbed over the wall tile to remove any haze which may remain from residual grout. With in vitro fertilisation (IVF), this is primarily due to the insertion of multiple embryos into the uterus. The sponging provides added moisture to strengthen the grout as it cures. This can vary depending on what types of fertility treatments are used.

The excess grout is scraped off with a hard rubber block called a float immediately after applying; further, the grout is wiped again with a moist sponge before it completely hardens. Women undergoing certain fertility treatments may have a greater chance of multiple births. The spaces between the tiles are filled with a fine cement called unsanded grout. Dizygotic twin pregnancies are slightly more likely when the following factors are present in the woman:. Modern wall tiles are fixed to a wall using a synthetic bonding agent tile adhesive for dry areas, or a cement-based mortar for areas prone to moisture, such as bath or shower walls. Some evidence suggests that the environment of the womb causes the zygote to split in most cases. Pictorial tiles, consisting of many tiles that the installer assembles like a jigsaw puzzle to form a single large picture, are available. Fewer than 20 families have been described with an inherited tendency towards monozygotic twinning (people in these families have nearly a 50% chance of delivering monozygotic twins).

Wall tiles are usually glazed, and are often patterned by painting or embossing. The cause of monozygotic twinning is unknown. These are usually ceramic, but other materials such as mirrored glass or polished metal can be used. Multiple pregnancies are usually delivered before the full term of 40 weeks gestation: the average length of pregnancy is around 36 weeks for twins, 34 weeks for triplets and 32 weeks for quadruplets. While ancient Roman building bricks were broader and thinner than modern ones and are therefore usually called tiles, the term wall tile is normally applied to finishing tiles. Before the advent of ovulation-stimulating drugs, triplets were quite rare (approximately 1 in 8000 births) and higher order births so rare as to be almost unheard of. See Laying tile
. If there are three, they are called triplets; four, quadruplets; five, quintuplets; six, sextuplets, seven, septuplets, and so on.

The spaces between the tiles are nowadays filled with sanded or unsanded floor grout, but traditionally mortar was used. Sometimes multiple births may involve more than two fetuses. Floor tiles are typically set into mortar consisting of sand, cement and oftentimes a latex additive for extra strength. Nevertheless, the rate of identical twins remains at about 1 in 250 across the globe, further suggesting that pregnancies resulting in identical twins occur randomly. Small mosaic tiles may be laid in various patterns. Thus, approximately 6% of children born in the US in 2001 were twins. Clay tiles may be painted and glazed. In 2001, for the first time ever in the US, the twinning rate exceeded 3% of all births.

These are commonly made of ceramic, clay, porcelain or stone. The widespread use of fertility drugs causing hyperovulation (stimulated release of multiple eggs by the mother) has caused what some call an "epidemic of multiple births". They include ridge, hip and valley tiles. The rate of twinning varies greatly among ethnic groups, ranging as high as about 6% for the Yoruba or 10% for a tiny Brazilian village (see [1]). There are also roof tiles for special positions, particularly where the planes of the several pitches meet. Historically, about 1 in 80 human births (1.2%) has been the result of a twin pregnancy. 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. Similar to vanishing twin.

Roof tiles are 'hung' from the framework of a roof by fixing them with nails. Occasionally, a woman will suffer a miscarriage early in pregnancy, yet the pregnancy will continue; one twin was miscarried but the other was able to be carried to term. These include:. A chimera may arise either from identical twin fetuses (where it would be impossible to detect), or from dizygotic fetuses, which could be identified by chromosomal comparisons from various parts of the body. Because of their long history, a large number of shapes (or "profiles") of roof tiles have evolved. A chimera is a person who is a completely normal human with no extra parts, but some of the parts actually came from his or her twin. Some clay tiles have a waterproof glaze. Sometimes the parasitic twin just becomes an almost indistinguishable part of the other.

Modern materials such as concrete and plastic are also used. One fetus acts as a parasite towards the other. Roof tiles are designed mainly to keep out rain, and are traditionally made from locally available materials such as clay, slate, or wood (wooden tiles are called shingles). Sometimes one twin fetus will fail to develop completely and continue to cause problems for its surviving twin. . This condition occurs in about 1 in 100,000 pregnancies.
. This occurs where the single zygote of identical twins fails to separate completely.

Tiles are most often made from ceramic, with a hard glaze finish, but other materials are also commonly used, such as glass, slate, and reformed ceramic slurry, which is cast in a mould and fired. Conjoined twins are monozygotic twins, whose bodies are joined together at birth. Tiles are often used to form wall and floor coverings, and can range from simple square tiles to complex mosaics. Early obstetric ultrasonography exams sometimes reveal an "extra" fetus, which fails to develop and instead disintegrates and vanishes. Less precisely, the modern term can refer to any sort of construction tile or similar object, such as rectangular counters used in playing games (see tile-based game). Researchers suspect that more pregnancies start out as multiples than come to term that way. The word is derived from the French word tuile, which is, in turn, from the Latin word tegula, meaning a roof tile composed of baked clay. Such conditions are usually associated with a higher incidence of other birth defects.

Tiles are generally used for covering roofs, floors, and walls, or other objects such as tabletops. This is where some or all of the organs will be on the opposite side of the body, such as the heart being on the right(Dextrocardia). A tile is a manufactured piece of hard-wearing material such as ceramic, clay, stone, porcelain or even glass. One mirror may or may not have situs inversus. Mission or barrel tiles are semi-cylindrical tiles made by forming clay around a log and laid in alternating columns of convex and concave tiles. They result from a late split of the fertilized egg at around 9-12 days. These result in a ridged pattern resembling a ploughed field. The incidence of mirror twinning is comparatively rare.

Pantiles - with an S-shaped profile, allowing adjacent tiles to interlock. These are identical twins with opposite features, that is one may be right handed and the other may be left handed; hair will whorl in the opposite direction, and so on. Roman tiles - flat in the middle, with a concave curve at one end at a convex curve at the other, to allow interlocking. Some percentage of monozygotic twins are called "mirror twins" or mirror image twins. This profile is suitable for stone and wooden tiles, and most recently, solar cells. (Fraga, et al., 2005). Flat tiles - the simplest type, which are laid in regular overlapping rows. Twins who had spent their lives apart (such as those adopted by two different sets of parents at birth) had the greatest difference.

50-year-old twins had over 3 times the epigenetic difference that the 3-year-old twins had. The number of differences between identical twins increases with age. A study of 80 pairs of twins ranging in age from 3 to 74 showed that the youngest twins have relatively few epigenetic differences. This is called epigenetic modification.

Identical twins have identical DNA but differing environmental influences throughout their lives affect which genes are switched on or off. There are usually obvious signs of differences when the identical twins are observed separately or together. Twins are unique individuals that establish their own individual likes and dislikes. Many identical twins spend most of their time together (especially as children), so people often assume that they will behave alike just as they look alike; however, this is not the case.

They develop their own individual personalities to enable themselves to be identified as individual persons. Identical twins can behave as differently as any other siblings (a matter of much interest to psychologists). The exact cause for the splitting of a zygote or embryo is unknown. While it was originally thought that identical twins do not run in families, but occur more or less randomly, some recent research has suggested that a genetic predisposition may exist.

As they mature, identical twins often become less alike because of lifestyle choices or external influences such as scars. Examination of details such as fingerprints can tell them apart. (On extremely rare occasions, an original XXY zygote may form monozygotic boy/girl twins by dropping the Y chromosome for one twin and the extra X chromosome for the other.) Monozygotic twins generally look alike, although sometimes they appear as mirror images of each other. Monozygotic twins are genetically identical unless there has been a mutation in development, and they are almost always the same gender.

About 50% of mono-mono twins die from umbilical cord entanglement. These twins may develop such that blood passes disproportionately from one twin to the other through connecting blood vessels within their shared placenta, leading to twin-to-twin transfusion syndrome. Monochorionic twins, sharing one placenta, usually also share the placental blood supply. For example, the umbilical cords of monoamniotic twins can become entangled, reducing or interrupting the blood supply to the developing fetus.

Sharing the same amnion (or the same amnion and placenta) can cause complications in pregnancy. Twinning after 12 days post-fertilization will typically result in conjoined twins. Twinning between 8 to 12 days after fertilization will usually result in monochorionic-monoamniotic ("mono-mono") twins. Twinning between 4 to 8 days after fertilization typically results in monochorionic-diamniotic ("mono-di") twins.

Zygotes that twin at the earliest stages will be diamniotic and dichorionic ("di-di"). The later in pregnancy that twinning occurs, the more structures will be shared. This condition does not occur for fraternal twins. Also note that any monochorionic or monoamniotic twins are identical twins.

All monoamniotic twins are monochorionic. Diamniotic identical twins may share the same placenta (known as monochorionic) or not (dichorionic). Depending on the stage at which the zygote divides, identical twins may share the same amnion (in which case they are known as monoamniotic) or not (diamniotic). The two embryos develop into fetuses sharing the same womb.

Identical twins occur when a single egg is fertilized to form one zygote (monozygotic) but the zygote then divides into two separate embryos. However, it is only the female that has any influence on the chances of having fraternal twins as the male cannot make her release more than one ovum. Studies show that there is a genetic basis for fraternal twinning—that is, non-identical twins do run in families. Dizygotic twins may be a different sex or the same sex, just as with any other siblings.

Dizygotic twins, like any siblings, have a very small chance of having the exact same chromosome profile, but most likely have a number of different chromosomes that distinguish them. The two eggs form two zygotes, and these twins are therefore also known as dizygotic as well as "biovular" twins. Fraternal twins (commonly known as "non-identical twins") usually occur when two fertilized eggs are implanted in the uterine wall at the same time. .

Since some premature births often have health consequence to the babies, twins birth are often handled with special procedures. Due to the limited size of the mother's womb, multiple pregnancy is much less likely to carry to full term than singleton birth (twins usually around 34 to 36 weeks). A fetus alone in the womb is called a singleton. The term twin most notably refers to two individuals (or one of two individuals) who have shared the same uterus (womb) and are usually, but not necessarily, born on the same day.

Several previous pregnancies. Greater than average height and weight. Between the age of 30 and 40 years. She is of African descent.

04-15-14 FTPPro Support FTPPro looks and feels just like Windows Explorer Contact FTPPro FTPPro Help Topics FTPPro Terms Of Use ftppro.com/1stzip.php ftppro.com/zip ftppro.com/browse2000.php PAD File Directory Business Search Directory Real Estate Database FunWebsites.org PressArchive.net WebExposure.us Display all your websites in one place HereIam.tv Celebrity Homepages Charity Directory Google+ Directory