Introduction to Ceramic Tile
Ceramic tile is often used as a "catch-all" term for a variety of wall and floor tiles. There are a number of materials used to make tile, each with their own unique characteristics and appeal.
What are ceramic tiles?
Ceramic tiles are tiles made from mixtures of clay, sand and other natural materials, which have been shaped and fired at a high temperature. This firing process hardens the clay to a durable surface.
Once fired, the hardened clay body, also called a bisque, may be left untreated or glazed to apply colors and designs and provide added wear and scratch resistance.
Unglazed tiles are preferred for commercial settings because the color runs throughout the body of the tile and therefore they do not show wear as readily as a glazed tile.
However, these tiles require sealing to prevent staining. Unglazed tiles are slip and wear resistant, possess a smooth, matte surface and tend to be thicker and denser than glazed tiles, and are therefore more suitable for high traffic and commercial applications.
Glazed tiles are made in the same way as unglazed tiles but have an additional glaze layer applied to the tile's surface that provides the tile with its color and level of shine or gloss, though the glaze can be transparent to allow the natural color of the clay to come through. The glaze is a hard, non-porous surface that improves the tile's resistance to water and staining.
Where Tile is Used
The most common residential uses for tiles are as interior floors, walls or countertops. Floor tiles may be glazed or unglazed and tend to be thicker and more durable than wall tile in order to withstand foot traffic. Floor tiles often have a more textured surface to improve slip resistance.
As a general rule, floor tile can be put on a wall or countertop, but wall tile should be used only on walls and countertops. Most wall tile is glazed with a high-gloss or semi-gloss surface. This glazed, glossy surface has a very low slip resistance, and is very slick when wet, adding to its lack of suitability as floor tile.
Porcelain and stone tile for outdoor walkways and patios is also a popular use of tile. Standard ceramic tile is not recommended for outdoor use because its water absorption rate is too high.
Features of Tile
The variety of tile colors, shapes, and sizes creates unlimited design possibilities and the versatility of tile allows it to be used on floors, walls, countertops, fireplaces—even outdoor applications. Tile is water and heat resistant making it great for kitchens and other wet areas of the home.
Tile is durable, fade and stain resistant (glazed tile or unglazed when properly sealed), and easy to maintain. Tile is considered a permanent floor because properly installed tile should last for the life of your customer's home.
What are porcelain tiles?
All porcelain tiles are ceramic tile, however not all ceramic tiles are porcelain. Specifically, porcelain tiles are ceramic tiles with a water absorption rating of less than 0.5%. This is why porcelain tiles can be used outdoors in exterior settings, as well as indoors; their low water absorption rating keeps them stable during freeze-thaw cycles.
Porcelain tiles are made from fine clays, quartz, and feldspar and fired at a higher temperature, resulting in a denser and more water resistant tile than standard ceramic tile. It is important to note that some manufacturer's now produce some high-density ceramic tiles that can be higher in density and strength than some porcelain tile.
While porcelain's construction has a durability benefit, it can make the tile more difficult to cut and adhere to vertical surfaces.
Types of Porcelain Tile
Glazed porcelain tiles are similar to glazed ceramic tiles, in that they have a layer of liquid glass-like finish, which is then baked into the surface of the clay.
The glaze may be clear or a different color than the tile and provides it with improved moisture and stain resistance. If the glaze is a different color than the bisque, chipping will be more noticeable than with unglazed tiles.
Natural or Unglazed Porcelain
Natural porcelain tiles, also called through-body porcelain tiles, have not been glazed nor polished and are the same color on the top and all the way through the tile. Unglazed through-body porcelain tiles do offer advantages over glazed tiles, including improved performance and wear resistance.
The low absorption rating of porcelain tile has nothing to do with the facial surface being stain resistant. Unless the tile manufacturer has treated the porcelain to close up the surface (micro) pores, a sealer will need to be applied to keep these tiles from staining.
Polished porcelains are natural porcelains with a polished surface. The polished surface isn't a glaze, but actually comes from within the stone, similar to the process used to polish granite or marble.
The polishing process on a porcelain tile actually opens up the pores of the tile and requires the tile to be sealed before grouting in order to increase resistance to stains and make the tiles easier to maintain
Ceramic vs. Porcelain Tile
Respond to the customer's concern in the text box below.
"I am not sure what kind of tile I need for my kitchen. What is the difference between ceramic and porcelain tile?"
At one time, the difference between ceramic and porcelain tile was more pronounced. Today, with the popularity of glazed porcelain and new high-density ceramic tiles with durability and strength ratings equal to most porcelain tiles, there is little difference for most residential application between these two types of tile.
Natural stone is very durable even in heavy traffic conditions and most stone tile is suitable for both indoor and outdoor use. All natural stone is porous to some degree and may absorb stains. Therefore, it is important to recommend a sealant to prevent stains from seeping into the pores of the stone.
The authentic appeal of natural stone makes it more desirable to some customers, despite the fact that ceramic and porcelain tile can realistically replicate the look of many types of stone.
The most common natural stone tiles used in the home include: marble, granite, travertine and slate. Each type of stone has distinctive features that influence its usability, appearance, and performance.
Quarry tile typically refers to any unglazed, machine-made tile. As with all unglazed tiles, quarry tiles require the application of a sealer or coating to provide stain resistance.
These tiles are made from a mixture of clays, chipped stone, sand or concrete with added color and are thick, durable, slip resistant, and have a high resistance to moisture and staining—making them perfect for heavy traffic areas.
Click to view sub-categories of quarry tile.
The main difference between a paver and a quarry tile is that quarry tiles are "extruded" and cut to length at the end of the extruding process, whereas pavers are typically pressed to form the desired shape and size.
Terra Cotta Tiles
Terra-cotta tiles are hand-made and unglazed. Most people use "terra-cotta" to refer to the color of the tile—a warm, natural reddish-brown derived from the clay they are made from.
Machine made, terra-cotta tiles are a form of quarry tile that are durable and have a lower moisture absorption rate than hand-made terra-cotta tiles
Glass tile is available in a wide variety of colors, patterns, textures, and sizes. These tiles may be opaque, translucent, or iridescent. Glass tiles are commonly used for bath and kitchen walls, countertops and flooring inserts, as well as spa and pool areas.
Today, some glass tiles are made from recycled materials such as old bottles, broken windshields and industrial scrap glass, which gives these tiles further appeal as a "green" product.
A variety of metals can be used to create metal tiles, including aluminum, copper, stainless steel, brass, bronze, pewter and others. These tiles are most often used as wall tiles or backsplashes in kitchens or as accents on floors and walls to add a unique, custom look to any area of the home.
Metal tiles are available in a variety of colors, textures and finishes. Shapes range from decorative dots, slender listellos, and mosaic tiles, to wall and floor tiles in standard sizes.
Just as with glass tiles, recyclable metal tiles have gained popularity because of their "green" story and positive contribution to the environment
Tile Shapes & Sizes
Tile whether ceramic, porcelain, stone, glass or metal is available in a range of shapes and sizes. This module will present some of the most common shapes, sizes and the typical uses for various shaped tile.
Field tiles refer to the tile covering a wall, countertop or floor. Typically these tiles are flat, single color and require border or trim tile to finish the edges of the installation.
Field tiles are most commonly square shaped, but are also available in rectangle, octagonal, hexagonal as well as custom shapes. These tiles are available in a wide range of sizes from 1-inch mosaics to 24-inches and larger format tiles.
Mosaic tiles are small tile or bits of tile (generally less than 3"x 3") that are commonly made from porcelain, ceramic, colored glass, natural stone and even pebbles. They are available in a variety of shapes such as round (dots) and hexagon.
Mosaic tiles are most often mounted on paper, mesh, or adhesive dot-mounted sheets to facilitate easier handling and installation. Mosaic tile may be used in a straight layout or separated and combined with different colors to form a surface design, decorative inset or custom pattern.
Trim tiles are designed to finish off the raw or cut edges of field tiles particularly on walls or countertops. These tiles are a required transition piece that provides protection to the raw edge—without the trim the field tile could easily be damaged.
Trim tiles are available in various shapes and sizes in order to achieve the desired sanitary and architectural design for the installation. Many tile collections also produce various coordinating trim tiles to blend in with field tiles in order make selecting trim tiles and finalizing a tile installation easier for the consumer.
There are two broad categories of trim tile: Surface and Radius trim.
Surface trim is applied directly to the wall or countertop surface and is typically the same thickness as the tile.
Radius trim is curved trim tile designed to go over a deep setting bed or a piece of tile.
Common shapes of both surface and radius trim include: bullnose, cove, quarter-round, and V-cap.
Bullnose is the most widely used trim for wall installations. This tile resembles a regular field tile with one rounded edge to finish off the top of a wall or the edge of a countertop.
Bullnose tile is sometimes referred to as a surface cap and can be used as a substitute for cove base.
A single bullnose has one rounded edge and can be used horizontally or vertically to finish off an area or turn direction.
Corner bullnose (also known as double bullnose or down angle): A ceramic floor tile trim that has two rounded finished edges on the tile to be used to complete a corner.
Cove Tiles (also called mud cap)
Cove tiles have one edge with a¬ curved in, concave radius and are used when installing wall tile to form a junction between the wall and floor, or to form an inside corner. These tiles are flared at the bottom to make a smooth transition from one surface to the next.
(1) Stack-on Cove Base – This wall tile trim flares at the bottom to segue smoothly to the floor. It has a flat edge on top and is used when tile will be installed above it on the wall.
(2) Sanitary Cove Base is a floor tile trim with a rounded finished top like a bullnose to cove up the body of the tile.
Quarter Round (also known as Bead) This is the trim piece used to finish the edges. If you look at it, it would look like a quarter of a round. Variations of these include a half round trim.
Beak is the outside corner trim that may be used with a Bead or quarter round.
V-CAP: (also called apron trim) V-shaped trim tile used on the front edge of a countertop. The tile's top surface is gently curved upward at the front edge to prevent water from running onto the floor.
Border tiles are primarily decorative field tiles that are used to define a transition. These tiles typically are differentiated from the field tiles by their shapes, size, design, color, or texture.
Some border tiles double as trim tiles, for example, v-cap on a counter can be a different color or contain a design or hand-painted detail that will act as a border. Many manufacturers also make ceramic versions of traditional wood moldings for use as borders, including profiles for base, crown, and chair rails to match the wall tile and provide a more decorative way to finish the installation.
Listellos are a decorative border tile, primarily used on walls that can provide a border for field tiles. These are often used to provide a visual break for a large field design or when the direction of the tile changes.
Decorative Tiles and Medallions
Decorative tiles are typically insets of a hand-painted or embossed design tile that that can be used to accent a field of tiles.
Medallions or inlays are typically pre-assembled designs created with stone or tile that are decorative focal points for a tiled area.
Tile is a fired product made from clay and other natural materials. Variation in color and shade from one tile to the next is an inherent characteristic of most tiles. With ceramic and porcelain tiles increasingly manufactured to look like natural stone, shade variation can sometimes be a welcome feature of a tile design, giving the installation a unique, natural and rustic appearance.
This module will present the types of shade variation and shade variation ratings.
Types of Shade Variation
Your showroom's lighting will most likely be quite different from the lighting in your customer's home. Even the increased presence of natural light in the room can make a big difference in the appearance of the color or shading of tile.
Offer to bring the samples she is considering to her home, when you perform the measure, in order to view the tile in the light of room and with other items from her décor.
Variation from Sample to Actual Tile
This type of shade variation is difficult to predict. If you are selling a product that has moderate to high shade variation, use a display vignette, or a display on the showroom floor of a similar type of tile, to ensure your customer is aware of the degree of variation.
Shade variation may also be created by they manufacturer to provide a random, unique looking installation. Be sure customers selecting products with a high degree of shade variation have seen photos of an installed layout and have looked at several tiles from the same production run to ensure the random and varied look is what they desire. If this is not possible, ask the customer to envision the various shades in a wall of bricks to create a mental image of shade variation.
Water absorption is an important characteristic of ceramic tiles. The amount of water the body of the tile will absorb reflects the tile's porosity, density, and strength.
This module will present a standard test method for determining the percentage of water absorbed by the body of a ceramic tile and explain why this rating is important for customer planning outdoor tile projects.
Water Absorption Testing
The water absorption test is used for both glazed and unglazed tiles. There are a number methods used to perform this test, the ASTM C-373 method (American Society for Testing and Materials) is one of the most common and is described in this module.
This testing method uses a number of individual tiles from the same lot, weighs them, soaks them with water, and then weighs the tile again. The percentage of weight difference between the two conditions is the water absorption rating.
The amount of water a tile will absorb is controlled by the raw material used in the body and the manufacturing process. It is the tile body that absorbs the water not the glazed surface.
Tile Absorption Rates
There are four categories for classifying tile absorption rates. Non-vitreous tile is the most porous and has a high water absorption rate, while Impervious tile has a very dense body structure and a significantly lower water absorption rate.
|Tile Category||Absorbs||Suitable Usage|
|Non-vitreous||More than 7%||Indoor only|
|Semi-vitreous||More than 3%||less than 7% Indoor only|
|Vitreous||More than 0.5%, less than 3.0%||Indoor. Can be installed outdoors in certain situations. Refer to manufacturer's guidelines.|
|Impervious||Less than 0..5%||Indoor & outdoor. The only frost proof tile.|
Typically, indoor areas, even those exposed to moisture, such as bathrooms and kitchens, will use glazed tile and the surface glaze is impenetrable to water. If unglazed tile were to be used in high-moisture, interior application, the water absorption rate would need to be considered.
The absorption rating is also a good indicator for the stain resistance for unglazed ceramic tile as the lower the water absorption rating, the greater the stain resistance.