Ceramic and Porcelain - Glossary

 

For definitions of other terms not listed here, please go to these sections: How Ceramic Is Made, Ceramic Styles and Before You Buy Ceramic.

 

ASTM

 

The American Society for Testing & Materials. The ATSM provides a rating system for manufacturers to use as a guide. The system suggests ratings for ceramic tile abrasion resistance, the overall durability of the tile, scratch resistance, moisture absorption, chemical resistance and breaking strength. These ratings are often in product catalogs or on tile samples.

 

Biocuttura Tile

 

Biocuttura Tile is also referred to as Double Fired Tile. A Biocuttura Tile is fired in a kiln at 2000 degrees Fahrenheit, then refired after the glaze is applied.

 

Bisque

 

The largest layer of a glazed tile. Just the top layer is referred to as the glaze.

 

Bullnose

 

Bullnose trim is a finished edge with only one rounded edge. It is sometimes used in place of a cove base trim.

 

Ceramic

 

Ceramic is made by the the process of clay and/or other nonmetallic minerals being shaped and then fired at extremely high temperatures.

 

CBU

 

Cement Backer Unit. Tile is applied to a CBU using mortar. The CBU is attached to the substrate and protects against water while also providing support. A popular, efficient method.

 

Classes 1-5

 

Classes that determine the appropriate traffic level for tile types.

 

 

Class 1: Tiles made for interior wall applications, not for floors.

 

 

Class 2: Tiles for interior wall applications or residential bathroom flooring. Very light traffic only.

 

 

Class 3: Tiles made for residential floor and wall use. Sturdy enough for light to moderate traffic.

 

 

Class 4: Tiles can be used for residential, medium commercial or light industrial floor or wall applications. Often used in malls, offices, hallways and restaurants.

 

 

Class 5: Tiles that can handle the heaviest traffic. Used in airports, subways and supermarkets.

 

COF

 

Rating system that measures slip resistance - the “Coefficient of Friction.” A higher number indicates higher slip-resistant properties. Important when selecting tiles for pool areas, bathrooms and rooms subject to water.

 

Corner Bullnose

 

A type of trim for ceramic floors having two rounded finished edges. Used for corners.

 

Extrusion

 

A tile style used to create a shape by pushing clay outside of a mold, instead of pressing the clay into the mold.

 

Field Tile

 

The most prominent tile pattern used in a multi-patterned ceramic tiled area.

 

Firing

 

Putting the tiles in a kiln at extreme temperatures. The fifth step in the process of creating ceramic tile.

 

Frit

 

A glass derivative that is used to create a glaze liquid. Frit and Dyes are used to prepare the liquid glaze.

 

Glaze

 

A coating for ceramic tiles using glass-forming minerals and ceramic stains. Usually a hard matte, semi-gloss or high-gloss finish that is non-porous and impermeable after applied and offers a higher stain-resistance and waterproofing standard than unglazed tile. Glazed tile has two layers. The top layer is the glaze, and the larger, bottom layer is the bisque.

 

Glazing

 

Glazing is the fourth step in the process of creating ceramic tile. Frit and dye are used to create a liquid glaze. Then glaze is then poured on the tile or put on using a high-pressure spray.

 

Green Tiles

 

Pressed Tiles. The third step in the process of creating ceramic tile.

 

Grout

 

A compound used to support tile joints and fill in space between tiles. There is cement based and epoxy based, as well as sanded and unsanded. Sand added to grout provides strength, but also scratches. Unsanded grout does not scratch and is used for soft stone. Epoxy based is highly stain-resistant and is almost always recommended. When grout color is required, pigment is added when the grout is mixed.

 

Impervious Tiles

 

Frost-resistant tiles used in exterior applications that can withstand heavy winters. There is less than a .5% moisture absorption rate in impervious tiles.

 

Moisture Absorption

 

Tiles can absorb moisture. The denser the tile, the less moisture it will absorb. It is important to take moisture absorption into consideration when choosing a tile type.

 

Monocuttura Tile

 

A tile that is fired at 2000 Fahrenheit only one time after the glaze application. Also known as single fired.

 

Mosaics

 

Tiles 2” x 2” or smaller that create a pattern or colorful inset. They may come in different sizes and shapes, and are often used in borders and wall applications.

 

Nominal Size

 

Ceramic tile can shrink at the firing process, sometimes by 10%. After kilning a 12” x 12” tile may actually measure 11 7/8 inches. The nominal size is 12” x 12”.

 

Non-Vitreous Tiles

 

Tiles that absorb a lot of moisture and are not meant for exterior use. The moisture absorption rate for non-vitreous tiles is around 7%.

 

Porcelain

 

A dense tile consisting of 50% feldspar that is highly resistant to scratches, is non-porous, and can handle weather extremes. It has a less than 0.5% water absorption rate. When created, porcelain is fired at a temperature higher than ceramic. It is highly suited for interior, exterior, heavy use, and commercial applications.

 

Pressing

 

Clay is pressed into a tile shape. Pressing is the third step in the process of creating ceramic tile. Pressed tiles are called green tiles.

 

Sanded Grout

 

Grout with added sand. Cement based and epoxy based grout have sand added. The sand gives the grout extra strength. If tile joints are 1/8th of an inch or more, sanded grout is suggested.

 

Sanitary Cove Base

 

A ceramic floor tile trim that covers up the body of a tile and has a rounded finished top. Similar to a Bullnose.

 

Semi-Vitreous Tiles

 

Tiles that are not suitable for exterior use. They absorb 3% to 7% moisture, therefore are only recommended for indoor use.

 

Shade Variation

 

The variation of shade in a ceramic tile. Results from firing. Variations depend on the dye used. Samples have shade variation ratings of low, moderate, high or random. Low means there is consistent shading and texture within that lot. Moderate and High indicate moderate or high shade and texture variations. Random indicates there will be large variations between shade and texture.

 

Substrate

 

The substrate is the material the tile is placed on. It is often a subfloor of concrete or plywood, but drywall or other material can be laid down on a subfloor to create a substrate.

 

Thickset

 

A method of installing ceramic tile by applying thick layers of mortar to a substrate. Thickset is sometimes called mud set. The thickset method is a laborious process and is less common today.

 

Thinset

 

A method of installing ceramic or porcelain tile by adhering it to a backerboard using a thin layer of mortar, then attaching the backerboard to the substrate.

 

Through Body

 

Tiles with a solid color that are not glazed are known as “through body construction.”

 

Tile Density

 

The weight, thickness and properties of a tile determines its density. A denser tile is a stronger tile. A denser tile absorbs less moisture. Density must be considered when choosing a tile type for your floor or wall application.

 

Unglazed

 

Tiles that are a solid color and do not have any glaze. Also known as “through-body construction.” They can be denser and last longer than glazed tile and can be used for interior or exterior use. They are available with different surface treatments, textures and sealants. A sealant will prevent staining.

 

Unsanded Grout

 

Grout without sand, usually used if tile joints are less than 1/8th of an inch. Sand provides additional strength to both cement-based grout and epoxy-based grout.

 

Vitreous Tiles

 

Frost-resistant tiles with a 3% or less moisture absorption rate. Although exterior tiles, they cannot be used in outdoor areas where freezing and thawing conditions might cause the tile to crack.