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Guide to PEI Tile Rating For Tile Durability

White ceramic tile installed on wall by hand

The Spruce / Margot Cavin

PEI tile rating is a system developed by the Porcelain Enamel Institute to quantify the hardness and durability of ceramic and porcelain tile.

The PEI rating process tests the surface wear layer of a tile's enamel glazing. PEI tile testing does not measure the fracture strength of the entire tile, nor does it offer any rating of the slip resistance of the tile.

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PEI tile ratings range from 0 (wall applications only) to 5 (heavy-duty floor traffic).

How PEI TIle Rating Helps

Ceramic and porcelain tiles are produced in different types for different uses. Some tiles are designed for use on walls only, others for floors, and some can be used for either floor or wall applications.

Tiles may also carry room recommendations for where they are best suited, based on finish, design, or surface texture.

PEI tile rating provides a shortcut to understanding if a certain tile will work in an application. A designer looking at a tile with a PEI rating of 0 will know that the tile is for light-duty use on walls only, not for floors.

Along the same lines, a designer building tile specifications for a restaurant will confine the tile choices to PEI 5-rated materials; or, those that are best suited for heavy commercial traffic.

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Always defer to the manufacturer's instructions for proper tile installation.

How PEI Tile Rating Is Determined

The PEI rating is a measurement of the surface enamel's resistance to abrasion. It is measured by the use of a machine known as a rotary abrasion resistance testing machine.

With this machine, steel ball bearings are pressed down and rolled over the surface of the tile while an observer watches the effect.

The ratings are issued based on the number of revolutions required before visible abrasions appear on the tile.

PEI Tile Rating System

A tile is given a PEI hardness rating on a 6-point scale: from 0 to 5. The assigned PEI class is based on how many revolutions of the testing machine are required before noticeable abrasions are seen.

PEI NR means that the tile is not rated. Usually, these are natural stone tiles. Stone tiles are never glazed, so they cannot be tested.

PEI Class Usage
0 Light-duty on walls only; never use underfoot.
1 Wall use only in residential and commercial applications. This type of tile should never be used underfoot. Shower surrounds are a typical PEI-1 tile.
2 Walls and light-duty floors. It's often used in residential bathrooms.
3 Countertops, walls, and floors that receive normal foot traffic. It's a good, general-purpose tile for all residential (but not commercial) uses
4 All residential applications (both walls and floors), as well as medium commercial and light institutional locations
5 All residential and heavy commercial and institutional foot traffic. Typically this is used only for flooring and is rarely attractive enough for interior residential applications.

How to Choose the Right Materials Based on PEI Ratings

Pay close attention to the PEI class when choosing a tile. A light-duty class 0 or 1 tile is likely to crack if used on floors, and a very thick class 5 tile may be so heavy that adhesives will have trouble holding it in place on a wall. The PEI class is not the only means of choosing a tile, however, and some tiles do not even carry a PEI class rating.

In addition to (or instead of) the PEI rating, tiles can be designated as floor or wall tiles based on other criteria. Tile designated for installation on a wall receives no foot traffic and, in fact, almost no wear of any kind. As such, this tile can be thinner and smoother, since safety is not a concern.

Wall tile can also have complicated designs, such as reliefs, that don't work well on floors. Tiles designated as floor tiles, on the other hand, often have a mat or textured finish to make them less slippery underfoot, especially in locations likely to experience moisture.

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Some companies omit PEI ratings entirely, giving only location/room recommendations.

Where to Find PEI Tile Ratings

The Porcelain Enamel Institute does not maintain a database of PEI ratings for tiles made by major manufacturers. Instead, you need to look at each tile's manufacturing details, often found in the fine print on the sales sheet or product specification sheet.

All companies provide some form of information on where the tile can be installed, either in the form of a PEI rating, a location specification (wall, floor, wall/floor), or both.

Beyond wall/floor distinctions, some companies go so far as to even list the rooms where the tile is recommended for installation—kitchens, bathrooms, hallways, etc.

Chosen tile pieces with white spacers in between

The Spruce / Margot Cavin