Ceramic wall tiles are normally less durable than tile designed specifically for flooring. Most wall tile is glazed with a semi-gloss or matte surface. The glazed surface has a very low slip resistance and becomes slippery when wet. Therefore, glazed wall tile is much more suited for wall or countertop applications rather than floors. 

Glazed ceramic tile is comprised of two basic elements: clay and water. Various clays are mined, ground, and blended to a fine powder. Then, they are pressed together. The tile is then dried to reduce moisture content. Next, the surface of the tile is coated with a colored glaze (similar to glass). The glaze is then permanently fused to the surface of the tile by firing it in kilns at approximately 2,000 degrees fahrenheit. 

Porcelain tile is made from a blend of fine-grain clays and other minerals to produce a very dense product that is highly resistant to moisture, staining, and wear. Because of these features, porcelain tile will withstand years of heavy foot traffic in both interior and exterior applications while maintaining its color and beauty. 

The densest of all tile types, ColorBody™ porcelain tile has a through-color body and is defined by its <0.5% water absorption. These tiles can withstand heavy foot traffic and are suitable for both indoor or outdoor applications. 

Most tiles are rated for hardness or scratch resistance using the MOHS Test and rating system. The MOHS test rates tile from 1 (softest) to 10 (hardest). Ceramic tile with a value of 5 or more is suitable for most residential floor tile applications. Tile with a value of 7 or higher is normally acceptable for most commercial applications or heavy traffic areas. 

To help select suitable tiles for specific applications, tiles are rated with the P.E.I. (Porcelain Enamel Institute) scale. The tiles are evaluated for wear resistance on a scale from 1 (lowest) to 5 (highest). 

• PEI 1: Light Traffic – recommended for residential bathrooms or other areas with light traffic where shoes are not frequently used.
• PEI 2: Medium Traffic – recommended for residential interiors except entryways, kitchens, stairs, or any area where tiles may come into contact with gravel or sand.
• PEI 3: Medium-heavy Traffic – recommended for all residential interiors and light commercial applications. Not recommended for commercial entryways.
• PEI 4: Heavy Traffic – suitable for all residential interiors and most commercial applications, including shopping malls and public areas. 
• PEI 5: Heavy-plus Traffic – all residential and commercial areas where heavy-duty wearability is needed. 

Ceramic tiles are also classified by their water absorption rate, which reflects the density of the body of the tile. There is a direct relationship between the water absorption rate and the suitability of the various types of tile for interior or exterior applications. Tiles suitable for exterior applications must have a very low water absorption rate, especially in climates subject to freezing and thawing cycles. These are typically porcelain body tiles, which have a moisture absorption rating of less than .5 %. 

As with many natural products, tiles will vary in shading. This adds to the beauty and design of the products. When choosing a tile, it’s best to view a few of the same types of tile together to visually determine the overall appearance of the tile.