All About Ceramic Tiles

Many homeowners and do it yourselfers have heard the term porcelain tile. This refers to tiles which are made from special “porcelain” clays and have been fired at very high temperatures. This process vitrifies the tile which makes it very hard, like glass. This also makes the tile dense, forms a strong solid structure and a hard surface which doesn’t absorb water (classified as impervious), doesn’t stain, and isn’t affected by wear and tear over time.

There are two main types of porcelain tile. Glazed porcelain and through-bodied porcelain. Glazed porcelain has a body made of the porcelain material and then a glaze is applied over the surface much like a regular ceramic tile. It is fired in a kiln and the result is a very strong bodied tile. Many tile manufacturers are switching their production to porcelain bodied tile because for a slightly higher cost, they can produce a superior grade tile - glazed porcelain tiles.

Through-bodied porcelain does not have a glaze. The clay is pressed and then fired. It may have texture and color applied to the surface before firing but it is still the porcelain material from top to bottom. The result is a strong tile that can withstand extreme surface traffic. There is no glaze that can wear off. If the tile chips, the same or similar color is underneath.

Because of the high cost of manufacturing this type of tile, only a very small percentage of the tiles you might see in a tile store are true through bodied porcelain tiles.

Most often this type of porcelain tile is installed by commercial users who have a need for the strength and durability of through bodied material.

Porcelain tiles typically have water absorption of 0.5% or less. Ceramic tiles have water absorption greater than 0.5%. Because porcelain tiles have a low water absorption, they are usually frost resistant – although, not always. To know if a tile is frost resistant, you should check the manufacturer’s literature and product specs. Porcelain tiles tend to cost more but are well worth the extra cost.

Understanding the terms shade and caliber
Ceramic Tile is a natural material with a natural composition which becomes resistant when fired at very high temperatures. This process, however, can cause slight differences in the shades of color of a tile between one batch and the next. Therefore, tiles are grouped before packaging according to their “dye lots” or shade and their caliber. The “dye lot” (or shade of that batch of material) is then indicated on the label of every box.

This is why when placing your order for tile, it is very important to order enough tile to not only complete the jo ut also to have extra for any repairs that may need to occur sometime down the line. Five to ten percent extra tile on most orders should be sufficient.

Grading of Tile
PEI ratings PEI rates are more applicable for floor tiles and are ratings that measure the abrasive resistance of the tile’s glaze on a scale of 0-5. This test is only for glazed tiles and does not apply to unglazed porcelain tile or other unglazed types of tile.

Class 1 (PEI 1): Recommended for wall use
May be used both on interior walls or bath floors without direct access to outdoor elements. 

Recommended for tiles that are suitable for residential bathrooms with light barefoot foot traffic. Some wall tiles may be used on the floor.

Class 2 (PEI 2): Light Residential Use
May be used where abrasive foot traffic is minimal – such as bathrooms, bedrooms, dining rooms, living rooms, and sunrooms. Tiles can be used in residential areas, but not areas with high foot traffic such as kitchens, hallways etc.

Class 3 (PEI 3): All Residential floors
For floors subject to normal foot traffic and usage (including kitchens, outdoor entryways and hallways). These tiles can be recommended for all residential installations with normal foot traffic.

Class 4 (PEI 4): All Residential floors and light-medium Commercial floors with moderate traffic Suitable for light to medium commercial applications. Will withstand light to moderate foot traffic in many commercial areas (commercial kitchens, hotel rooms, small offices, etc).

Class 5 (PEI 5): All Residential and busy Commercial
Ideally suited for all residential and heavy traffic commercial areas under normal foot traffic conditions (shopping centers, hotel lobbies, hospitals, and industrial applications). For very high traffic areas, consider an unglazed through-body color porcelain.

Ceramic tiles are made from a mixture of clays that are pressed into shape and fired at high temperatures to give the tile its hardness.

Ceramic tiles are then either glazed or not. Glazed tiles are the most common style today in floor and wall tiles as well as for residential and commercial applications. Glazing is done by applying liquid glass to the body of the tile, and firing it at high temperatures so the glazing becomes hard and non-porous. Shiny glazes are softer, can be scratched easier, and can be more slippery than satin or rustic finishes.

Unglazed tiles, on the other hand, are very durable and don’t show the effects of heavy traffic. The most common unglazed tiles are red quarry tiles or the granite-looking porcelain ceramic tiles that are used in heavy commercial areas.

The color of the body of the tile (as opposed to the surface) is determined by the color of the clay available in the manufacturer’s area.

Ceramic tiles can be manufactured in one of two ways, called: - Bicottura (’double fired’) - the clay body is fired on the first pass through the kiln, and then the glaze is applied and fired on the second pass through. - Monocottura (’single fired’) - the tile passes through the firing process one time at a temperature of 2200 degrees. Monocottura tiles have denser bodies and harder glazes than Bicottura tiles.

As the weight or density of the tile increases, the stronger it becomes, but the less moisture it can absorb. Which is something you should keep in mind, depending on where you plan to use them. They’re graded, from ‘Non-Vitreous Tiles,’ which can absorb the most moisture, through ‘Semi-Vitreous’ and ‘Vitreous,’ to ‘Impervious Tiles,’ which absorb less than .5% moisture.

Ceramic tiles are a popular tiling material that is widely used to design households and commercials. It’s highly popular due to its extraordinary physical and chemical properties. These tiles can be utilized to designs your floors, walls, counter tops, black splashes, fireplaces and walkways. Hence, they can be used to create an elegant and royal look for your homes.

Nowadays, you can find glazed and unglazed ceramic tiles. The glazed tiles have a thin coating on its surface while unglazed tiles are sold in their natural state. The liquid glass coating is responsible for the amazing texture, color and design of glazed tiles. Therefore, glazed tiles are available in different range of colors and designs.

However, glazed ceramic tiles have several properties like:

They are stain resistant and can be cleaned with help of chemicals like soda and acid. Hence, you can use them to design you kitchen shelves and floorings, since the area is highly prone to dirt and stains.

These tiles are less prone to scratches and stain due to falling or dragging of objects from one part of room to another.

Glazed tiles are fire resistant; hence they retain their shine and shimmer despite being exposed to fire or heat.

The color of glazed ceramic tiles doesn’t deteriorate on exposure with harsh sun rays.

Glazed tiles are slip resistant and ideal for designing bathroom and kitchen floors.

However, the glazed tiles don’t have any glass coating on their surface. Their colors fade after sometime and lose its shine. Moreover, the color is widely distributed throughout the surface; hence they lose their beauty once they get worn out. They are available in earthy colors like light brown, peach, gray etc.

Hence, you should be particular about your tiling needs, while you purchase ceramic tiles for your households and commercials.

Jason Colling is a renowned writer, who has written articles on various interior designing techniques related to floor decor. His articles focus on various uses of porcelain tiles, ceramic tiles , granite tiles,natural stones and adhesives.

Source: Superiority And Popularity Of Glazed Ceramic Tiles
Something About Ceramic Tiles | Ceramic Glazed Tiles

The earliest forms of ceramic tile date back to prehistoric times, when the use of clay as a building material was developed independently in several early cultures. The precursors of modern tile were roughly shaped and not nearly as strong as tiles today. The material was dug from river banks, roughly formed into building blocks, and baked dry in the sun. The first tiles were crude, but even 6,000 years ago people were decorating them by adding pigments for color and carving low-relief designs into their surfaces.

Firing Tile

The ancient Egyptians were the first to discover that firing clay tiles at high temperatures in a kiln made them stronger and more water-resistant. Many ancient cultures also used thin squares of fired clay as decorative elements in their architecture.

Buildings in ancient Mesopotamian cities were fronted with unglazed terra-cotta and colorful decorative tiles. Ancient Greeks and Romans used ceramics for the floors, roofs, and even the plumbing in their buildings. The Chinese used a white clay called kaolin to develop the white-colored and durable ceramic known as porcelain.

Tiles in medieval Europe were generally reserved for the floors of churches. Across the continent, the Byzantines excelled in using tile at a small scale; they created expressive mosaic patterns and murals using ceramic tile as well as pieces of glass and stone.

Glazing Tile

Persian ceramicists, inspired by imported Chinese porcelain, created a decorative tradition that spread across South Asia, North Africa, into Spain with the Moors, and eventually throughout Europe. Because their Islamic religion prohibited using human images in art, artisans turned to brightly colored tiles with ornate and intertwined patterns.

Solid-color glazed tiles were cut and assembled into large-scale mosaics with subtle color gradations. The Muslim artisans also developed metal oxide glazes using tin, copper, cobalt, manganese, and antimony, which made tile glazes more brilliant and durable.

By the fifteenth century, metal oxide-glazed tile had become popular in Italy, and their design influence moved northward with Italian craftsmen. Major European trading centers gave their names to local design motifs and types of tile that are still used, including delft tile (from Delft in Holland), and majolica tile (from Majorca in Spain).

Modern Tile

Today, most commercial tile manufacturers use the pressed-dust method of construction. First, a mixture of ingredients is pressed into the desired tile shape. Then the tile is glazed (or left unglazed) and baked in a kiln. Some tile makers may extrude tile shapes by squeezing them through a press into a die or by rolling them out flat and cutting the tile shapes with a form much like a cookie cutter.

Whatever the method, all ceramic tile must be fired to become durable. The purity of the clay, the number of firings, and the temperature of the kiln determine the quality and price. Kiln temperatures vary from about 900° F to 2500° F. Lower firing temperatures produce more porous tile and soft glazes; higher temperatures produce dense, nonporous tile and hard glazes.

Source: A Brief History of Ceramic Tiles