How to Find Out the PEI on a Tile

PEI Rating Overview

• The Porcelain Enamel Institute developed tests to help manufacturers and consumers identify the surface abrasion resistance of a tile. While many buyers mistake PEI rating as a measure of hardness or durability, this rating only measures how well the glazed surface of the tile can withstand wear and abrasion.

PEI Scale

• PEI ratings range from 1 to 5, and the higher the rating, the better the tile is able to resist abrasion. Tiles with a PEI rating of 1 are not designed to withstand foot traffic, and should only be used on walls. A PEI rating of 2 means the tile can be used on the wall, or on floors exposed to light foot traffic, such as the bathroom. Tiles rated as PEI 3 can withstand normal foot traffic, making them appropriate for most residential applications. A PEI of 4 means the tile can withstand moderate to heavy traffic, and can be used in any residential and most light commercial or industrial applications. Tiles rated at PEI 5 can withstand heavy to extra-heavy traffic, and can be used in any application.

Where to Find It

• Manufacturers typically don't include PEI ratings on the tile itself. Instead, this information can be found on the box, or on product sales and data sheets available from the manufacturer. Manufacturer websites and product websites for home improvement stores and tile distributors often include PEI ratings for tiles. While there is no industry standard symbol associated with a PEI rating, a tile rated at PEI 3 may be shown as "Class 3" or as "PEI 3." One major home improvement warehouse uses a symbol of a drill bit drilling through a tile with a number below to indicate the PEI rating.

Other Ratings

• In 2008, the American National Standards Institute modified its publication A137.1, which provides ratings on visible abrasion for glazed tiles. This standard is based on test method C102.7, developed by ASTM International. This rating system, which shares many properties with the PEI scale, ranges from 0 to 5, and the ratings fall roughly in line with PEI ratings regarding where the tiles should be used. Tile Magazine suggests this standard, which often is referred to as A137.1 or C102.7, provides more accurate information about real-life wear and abrasion than other systems, particularly for darker tiles. Some manufacturers use this rating system rather than the PEI scale to provide information about tile wear resistance.

Grade vs. Rating

• As you review PEI ratings listed on a tile box or manufacturer website, be careful not to confuse information on the grade of the tile with the class or rating. "Class" and "rating" generally refer to abrasion and PEI, while "grade" refers to the quality of the tile. A grade 1 tile features the highest quality, with few imperfections, while grade 2 offers a slightly lower quality and more imperfections per box. Grade 3 tiles are of the lowest quality, and are meant for use on walls but not floors.