Ceramics have been made for centuries both for utilitarian needs and as expressive art forms. Tiles made from ceramics have been used as floor, wall, and roofing materials. Today ceramics are also used to make bricks, drain lines, and chimney flues.
Ceramics are made of clay that is shaped and fused or vitrified by firing in kilns. Ceramics can be unfinished, carved, painted, or glazed. Different clays, additives, and glazes are combined to produce many variations in color, finish, and strength in ceramics.
Types of clay:
- Primary Clays –
- Produced within the vicinity of the parent rock. Ex. Kaolin
- Pure materials and are less plastic.
- Secondary Clays –
- Clays are transported by water.
- Have a higher degree of plasticity
They are classified into four general types based on their firing temperatures:
Earthenware and Stoneware
Earthenware is made of coarse-textured clay fired at relatively low temperatures and can be glazed if needed. It is usually porous, fragile, and opaque in its finished state. Colors of earthenware, sometimes referred to as terra-cotta (meaning cooked earth), tend toward red or brown.
Objects such as bricks, flooring tiles, flower pots, tiles, and folk pottery are commonly made from earthenware.
- They are manufactured from a wide range of clays.
- Glazed bricks are manufactured in wide varieties of high gloss, uniform, or mottled colors.
- For roofing tiles, raw materials are screened to a finer grade than the brick.
- Clay is more finely divided to produce intricate details for building components.
- Terracotta blocks can be readily molded, are durable, and are cheaper than stone.
- Modern blocks are also used as outer walls for cavity construction.
- The glazed terracotta is resistant to weathering, frost, or ultraviolet light.
- It is manufactured from secondary plastic clays with added feldspar. Stoneware is made of finer clays than earthenware and is fired at medium temperatures,
- It is waterproof, has high chemical resistance, is strong, less porous than earthenware, and is durable.
- Colors are usually gray or light brown, and glazes can be given a matte finish, showing flecks in the glaze or clay.
- Most of the unglazed vitrified clay pipes are stoneware.
- Stoneware ceramic panels are used for flooring tiles and cladding panels for facades. Also as casual dinnerware, cookware, and sculpture.
Porcelain and China
Porcelain is the highest grade of ceramics and is made of feldspar (crystals) and white clay (kaolin). It is fired at high temperatures, causing it to vitrify and become waterproof even if chipped. It is a very hard, white, translucent, and high-quality material that resists chipping.
It is often used for fine dinnerware, artwork, and finishes on sinks and bathtubs.
A hard, translucent porcelain (made from a high proportion of animal bone ash) is called bone china or English china. China is fired at a much lower temperature than porcelain, but it is more durable than earthenware or stoneware. Vitreous china is used for the manufacture of sanitary ware.
One of the most popular uses for ceramic as a building material is tile for floors, walls, cabinetry, tubs, showers, and even ceilings. Tiles are made in numerous materials, sizes, shapes, thicknesses, and surface textures. In addition to ceramics, tiles can be made with glass, stone, and even metal additives. They are classified as having impervious, vitreous, semi-vitreous, and non-vitreous qualities.
Tiles are installed in Portland cementitious setting beds (thickset) or with special epoxy adhesives (thin-set). As in bricklaying, patterns, and joints can vary a great deal. Grout, in many colors and finishes, is added between the tiles in various widths, depending on how the tile is used.
Ceramic tiles are made from different clays and shale mixtures. They are fired at different temperatures to produce specific glazes, surface finishes, and hardness. Ceramic tile is produced in three basic types-glazed, mosaic, and quarry-as well as other miscellaneous types.
Glazed and Mosaic Tiles
Glazed ceramic tiles are used in many ways, both in building exteriors and interiors. They are produced in modular sizes and often have matching trim pieces for corners, wall bases, and nosings. Mosaics are an assembly made of small pieces of glass, stone, tiles, and other materials. Mosaic ceramic tile is made in small sizes for composing intricate patterns for use in murals on floors and walls.
Mosaic tiles are made with clays, porcelain, or glass, and sometimes are produced in units with a back-mounted fiber mesh to facilitate their handling and installation. These are generally smoother, brighter, and more impervious than other glazed tiles.
Quarry and other Tiles
Quarry tiles, made of graded shales and fine clays, are among the thickest and strongest of the tiles. Their color is usually a result of the type of clay used. Quarry tiles generally are left unglazed in their terra-cotta state. Traditional quarry tiles are long-lasting and excellent for floors that receive a lot of abrasions. Quarry tiles are also produced in a variety of colors, tints, and finishes.
Ceramic tile is also manufactured into durable roofing tiles, which can be flat pieces or rolled into interlocking sections that resemble Mediterranean roofing.
Digital tiles are made as custom tile printing utilizing inkjet printers and ceramic inks with digital images of photography and art, to produce photographic images/patterns in restaurants, kitchens, showers, and many other locations.