1. ABRASION (resistance to)

    Abrasion resistance is the resistance of a surface to wear and tear (for unglazed tiles) or to change its appearance (for glazed tiles).


    According to UNI EN norms, abrasion resistance is classified with PEI grades, where PEI 1 corresponds to the lowest resistance and PEI 5 corresponds to the most resistant tiles.

    For unglazed tiles, abrasion resistance increases with the decrease of water absorption therefore it is high in the case of porcelain stoneware.


    The abrasion resistance value can also change depending on the treatments carried out on the tile surface:

    in the case of terracotta tiles, for instance, the impregnation using natural or synthetic substances and for porcelain stoneware any polishing treatment.

    For glazed tiles, abrasion resistance exclusively depends on the glaze: light colour glazes tend to show the effects of use more, also due to their more complex cleaning.

    See also: Surface mechanical features.


    The key safety feature for a tiled surface is its slip resistance, particularly for tiles destined for outdoor, public and industrial destinations. A slippery surface creates an architectonic barrier making walking on the surface difficult and treacherous, particularly for those suffering from either a permanent or temporary physical disability. The slip resistant value of tiles should be known and checked before proceeding with installation.


    Currently, there are no internationally recognised standard methods to test slip resistance, almost every country has its method derived from local laws and regulations. Many of these test methods are different and they cannot be correlated either on a theoretic or experimental basis. This situation often leads to confusion for customers and planners who must guarantee the compliance with regulations and creates problems to tile manufacturers when they need to classify tiles according to slip resistance.

  3. ASTM C1028 METHOD

    See Safety features >>


    Stage of the productive process that has the function of drying the ceramic mix (slip) following the wet milling of raw materials, in order to obtain atomized powders that will undergo a semi-dry pressing.

    The slip is sprayed in a hot air current, therefore the drops dry quickly and become spherical grains that are internally hollow and that contain a moisture residue (ranging from 4 to 8%) as this is useful as a lubricating agent during the following pressing procedure.