What does the PEI rating mean?

Answer: The Porcelain Enamel Institute developed a wear abrasion testing procedure in the 1940's that is still used today. This test is used to classify tile according to it's field of use and the expected type of traffic and abuse the tile is likely to experience. It is a wear rating specifically for glazed ceramic tile surfaces. PEI 0 is specifically designed to identify those tiles that have a wear rating unsuitable for use on floors. PEI 1 and 2 are for use in areas with softer, abrasive dirt-free footwear (bathrooms, bedrooms). Many times these are high gloss or intensive coloured tiles. PEI 3 is for areas in contact with normal footwear including heavier residential traffic, but without dirt and grit action (hallways, kitchens). PEI 4 is for most all residential floor areas and tiles suited to public areas where moderate to heavier traffic occurs (hotel lobbies, restaurants, supermarkets, and even banks) PEI 5 is for where there is probable concern over the wear required for the busiest commercial traffic floors. PEI 5 is chemically more resistant as well and is categorized as a hyper-resistant glaze

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What’s the difference between the Mohs rating and the PEI rating?

Answer: Minerals with predetermined hardness ratings are pulled across the tile. The mineral that succeeds in scratching the tile determines it's rating. This test is commonly performed on glazed tiles, but can also be used to determine how easily polished porcelains or other specially finished tiles will scratch. The most commonly used original MOHs scale has ratings ranging 1-10, with 10 being diamond, the highest rating. The higher the rating, the more scratch-resistant the tile. A rating of 7 or better is preferable - 7 being quartz, which is a primary raw material in ceramic tiles. Materials, Mohs hardness, and the (( Revised)) Mohs scale. Talc 1 ((1)) Gypsum 2 ((2)) Calcite 3 ((3)) Fluorite 4 ((4)) Apatite 5 ((5)) Orthoclase 6 ((6)) Vitreous pure silica ((7)) Quartz 7 ((8)) Topaz 8 ((9)) Corundum 9 Garnet ((10)) Fused zirconium oxide ((11)) Fused alumina ((12)) Silicon carbide ((13)) Boron carbide ((14)) Diamond 10 ((15)) Bright glossy glazes do not usually offer particularly good surface hardness (5 - 5.5); while those matt products, or products with surface crystallization, may reach and exceed a Mohs value of 7. Some specialty glazes have a Mohs 9 corundum glaze. Unglazed vitrified (low water absorption) tiles usually are 7 on the Mohs hardness scale.

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How do you measure slip resistance?

In North America we use the ASTM 1028 scale where anything over .6 is considered to have excellent Slip Resistance or friction. The United States ANSI method gives, through the use of a force gauge (horizontal dynamometer) pull meter method, the static friction coefficient of the surface. Equal to or greater than .60 - excellent friction, Equal to or greater than .50 - adequate, Equal to or less than .40 - caution necessary.

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