Ceramic Tile wear and tear 101

The Porcelain Enamel Institute (PEI) has a scale that was created to determine the resistance of an enameled surface in relation to the traffic and wear the surface will endure. Once assigned a rating, tiles can be evaluated to better determine which tile to use for a given application. The PEI Rating of ceramic tile is one factor to help determine it's appropriateness in a project.

The Porcelain Enamel Institute was founded in 1930 and has three primary objectives aimed at advancing porcelain enameling manufacturers and suppliers thereof:

1. To promote manufacturer's new products and their process improvements to manufacturing operations.


2. To provide general promotion of porcelain products.


3. To advance and protect the porcelain industry.

PEI achieves these objectives through representation from all segments of the porcelain industry, who work together to offer various programs and services to industry executives.
The PEI Scale, or PEI Rating, is a vital tool when deciding which tile is best for you because it classifies the ceramic surface in terms of how much wear the tile can bear without damaging its appearance.

CLASS 0 - Tiles technically unsuitable for floors.
CLASS 1 - Residential and commercial wall and bare foot traffic.
CLASS 2 - Wall and residential bath floor, and soft soled traffic.
CLASS 3 - All residential floors and light commercial floors.
CLASS 4 - Medium commercial, light industrial and institutional, moderate soiling.
CLASS 5 - Extra heavy traffic, abrasive dirt, chemically more resistant.


While it is true that the higher the PEI rating, the greater the resistance of the enamel, the PEI floor rating is not the only factor that should be evaluated when choosing a tile.
  Other factors to consider when choosing porcelain tile include:

• shape and dimension


• visual inspection


• coefficient of friction (how easily an object moves across the surface of the tile); water absorption


• bond strength


• breaking strength


• abrasive hardness, chemical resistance


• crazing (resistance to cracking)


• freeze/thaw resistance


• impact resistance


• MOHS scale scratch test (how easily the tile scratches)


• acid resistance


• water penetration through glaze


• cleanability


• marking resistance to metals

Of these factors, the three considered the most important are the PEI rating, the water absorption, and the glaze hardness (MOHS scratch test).

In addition to these structural characteristics, the tile's aesthetic qualities are very important to consider. Ask yourself if the edges are square or warped, is the surface texture consistent, are the tiles are the same size and is the coloring consistent. High quality tiling translates to a high quality floor. The grout lines will be uniform, the colors will be consistent, the floor will have a consistent height, your project will go much faster, and you'll be more satisfied with your new floor.
Largely due to the Porcelain Enamel Institute, ceramic floors are becoming more popular with consumers today. The PEI has helped to improve the strength and durability of tile, as well as the design, color, and other visual aspects of tile. With the assistance of the Institute and the PEI scale, look for continued improvements by the tile manufacturers and continued expansion in tile selection for consumers.