Ceramic Tile
The word ceramic can be traced back to the Greek term keramos, meaning "a potter" or "pottery." Keramos in turn is related to an older Sanskrit root meaning "to burn." Thus the early Greeks used the term to mean "burned stuff" or "burned earth" when referring to products.
Porcelain and ceramic tile are essentially the same product, the difference being the end result out of the kilns. The overwhelming popularity of ceramic and porcelain tile stems from the fact that the material is available in a wide range of shapes, colors and texture and generally requires lower maintenance and is infinitely easier to clean than natural stone, granite and marble.
Ceramic tiles cover a wide range of properties - typically they are glazed (although there are some exceptions) and the glaze layer can be extremely durable. Oftentimes, ceramic tiles can be used in freeze thaw environments in the cases where they are manufactured with properties similar to porcelain tiles. Check with the supplier or manufacturer for more specific details on your chosen product.
The making of ceramic tile is a process unique because of the special qualities of the materials inputs. The manufacturing process of making ceramic tile begins with the mining of feldspar and clay minerals from the earth. The raw clay materials are pulverized and crushed in a multi step process that can involve up to three separate crushing mechanisms depending on the size of the particles.
The small particles are then separated by size using screens. Tiles come in different grades and can have different colored bodies, both factors at least partly determined by the proportion of different clay materials combined in the tile mixture. The combination of the type and amount of specific clays is measured out carefully and mixed together, a process during which they are further ground up. The ceramic tiles are then formed using this mixture either by the dry pressing method or wet milling.
There are different machines and methods of pressing the mixture into the correctly shaped tiles and similarly there are different methods of applying the glaze. The glaze can change the texture of the tile as well as the color, pattern and feel of it. The dry milled ceramic tiles are bisque fired at relatively low temperatures before they are glazed, then they are glazed and re-fired for up to 2-3 days at temperatures of approximately 2,300°F. The wet milled tiles take less time to fire, sometimes as little as 60 minutes, at temperatures of approximately 2,100°F.
This single firing process is called monocottura and makes harder, stronger tiles. Technology in the ceramic tiles business is perpetually changing and there are now processes that form the tiles and glaze them simultaneously.
Once in the customers home, installation isn’t terribly difficult and can often be done by a do it yourselfer with moderate fix and repair skills.
The nice thing about Ceramic tiles is that they are easier to bond to the floor and usually easier to cut than Porcelain tiles. Porcelain tiles are harder to bond and harder to cut because of the dense properties of the material. While this can be relevant to the tile installer, it generally makes little difference to the end-user, so long as the installer uses the right installation materials.
Porcelain Tile
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.
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.
