What is the PEI rating?
The PEI rating is the abrasion class of a glazed ceramic tile. It runs from PEI 1 to PEI 5 and indicates how much foot traffic the glaze will take before visible wear appears. The abbreviation comes from the Porcelain Enamel Institute; the test method is set out in EN ISO 10545-7.
In the test, an abrasive mix of steel balls and grinding medium is rotated over the glaze for an increasing number of revolutions. The revolution count at which wear becomes visible determines the class.
The five classes
- PEI 1 — only rooms walked on barefoot or in soft slippers, with no grit brought in: bathroom, bedroom.
- PEI 2 — light traffic with soft footwear and little abrasive dirt.
- PEI 3 — normal domestic use with outdoor shoes: kitchen, hallway in an average household, balcony.
- PEI 4 — heavy traffic and abrasive dirt: busy entrances, shops, offices, hospitality.
- PEI 5 — very intensive use and public areas.
What the PEI rating does not tell you
This is where people go wrong most often. The PEI rating covers only the wear resistance of the glaze. It says nothing about:
- Frost resistance. That is a separate property, tied to the water absorption of the body. For outdoor use you need a frost-resistant tile, whatever the PEI class.
- Slip resistance. That is the R rating (R9 to R13), or the A/B/C classification for wet barefoot areas.
- Stain resistance and scratch resistance. A high-PEI tile can still hold stains.
- Unglazed tiles. Full-body porcelain and natural stone get no PEI rating, because there is no glaze layer to wear away.
Choosing in practice
For an average home, PEI 3 in the living room and kitchen and PEI 4 in the hall and entrance is enough. In a household with dogs, children and a garden door, go one class higher — the price difference between PEI 3 and PEI 4 is usually small compared with tile and laying costs combined. Dark, high-gloss tiles show scratches and traffic lanes sooner than pale matt tiles of the same PEI class.
Related terms
- Glaze
- Slip resistance
- Tile adhesive
- Screed
- Porcelain stoneware
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