The PEI rating tells you how well the glaze on a tile resists surface wear from foot traffic. It runs from class 0 to class 5, and is tested to ISO 10545-7.
Most homes need class 3 or 4 on floors. Busy shops, offices and public areas usually need class 4 or 5. PEI applies only to glazed tiles, such as GVT, PGVT and ceramic floor tiles.
How the test works
The name comes from the Porcelain Enamel Institute, which developed the original method. Today the test is ISO 10545-7.
A machine places steel balls and an abrasive powder on the glazed surface and rotates them for set numbers of revolutions. After each stage, the tiles are compared with untested tiles under standard lighting. The class depends on the stage at which wear becomes visible. Class 5 also requires the tile to pass a stain test after the highest stage.
The classes and their typical uses
- Class 0: not recommended for floors.
- Class 1: walls, or floors walked only barefoot or in soft slippers, such as some bathrooms.
- Class 2: residential rooms with soft-soled shoes and little grit, such as bedrooms.
- Class 3: all residential floors, including kitchens and corridors, and light commercial rooms.
- Class 4: busy residential floors and most commercial areas, such as shops, offices and restaurants.
- Class 5: heavy commercial and public traffic, such as malls, stations and airports.
These uses are guides. Grit from outside wears tiles much faster, so a ground-floor entrance needs a higher class than an upstairs room in the same building. Entrance mats help a lot.
What PEI does not tell you
- It does not measure strength. That is breaking strength, covered in what breaking strength means.
- It does not measure slip resistance. See slip resistance and R ratings.
- It does not apply to unglazed tiles such as double charge and full body. Those use the deep abrasion test, ISO 10545-6.
- It does not rate scratch hardness from sharp objects, which is a separate property.
Why finish and colour affect the rating
Wear is easier to see on dark, glossy tiles than on light, matt ones. So the same body can earn a different class in different glazes. A black polished design may rate lower than a beige matt design from the same factory.
That means a PEI class belongs to one product and finish, not to a factory. Ask for the result for the exact design, or at least the same glaze and colour family.
What to ask the factory
Ask for an ISO 10545-7 report from an accredited lab for the design and finish you are buying. Check that the class printed on boxes and data sheets matches the report. For commercial projects, put the minimum class in your purchase order, so a lower-rated glaze cannot be substituted. Our founding guide on reading a lab certificate explains what to check.
Next step
Choosing the right PEI class avoids worn floors and unhappy customers. We match designs to the use you plan and have lots tested before loading. Book a free sourcing review to get started.