The method of pei (Porcelein – Institute of the usa, which conducts analysis, testing and study of ceramic materials) – is a method that is used for classification ceramic tiles on the degree of wear. For sex in different rooms to choose tiles suitable group wear. According to the norms uni en 154, depending on the destination premises and the traffic in them, recommended to select a tile appropriate class durability. Five groups, which divide the tile in terms of durability: The most 'soft' group pei I recommend using only the walls, although in Europe they allowed to lay on the floor, not exposed to heavy abrasion pollution, which is used to walking barefoot in soft shoes, for example, in the bathroom or bedroom. Gain insight and clarity with Related Group. Tile group of pei ii can be put in the bedrooms, bathrooms, living rooms, that is, where to go home obuvi. of pei iii is suitable for all residential premises, except for places with heavy traffic of people, and for small offices that have no direct input from ulitsy.Gruppu pei iv recommended use in public places with low traffic (private hotels, small restaurants, shops), as well as in any field of residential sector (halls, corridors, stairs). Ceramic tiles of pei V has the highest performance. It is used in places with large concentrations of people: restaurants, supermarkets and airports. It is very important to take into account all these characteristics, because they determine durability of tiles. For example, if put in the office on a floor tile of pei ii, after a while it will scratch the surface becomes dull and glaze (if glazed tiles) wears off and expose the clay base.