Concerning the safety of the final user, the slipperiness of a floor, directly linked to the coefficient of friction, is particularly important. The En ISO 10545-17 standard describes various possible methods for measuring the coefficient of friction, each one of which is specific for a different country.
The BCRA method
For Italy, the Ministerial Decree N° 236 of 1989 requires, for some types of constructions, that floors are anti-slip, that is that they have a coefficient of friction measured by the BCRA method (British Ceramic Research Association) of over 0.40. Tests are carried out by simulating both rubber soled shoes on a wet floor and leather soles on a dry floor.
The "R" coefficient (Germany)
The DIN 51130 standard is applied in Germany (but is well-known in other countries as well) for the classification of tiles on the basis of their slipperiness.
The first safety level is called R9, the second R10 and so on up to R13. Materials that do not come up to the first level R9 are not considered suitable and safe, while on the other hand the use of a R13 product, particularly rough, means care in cleaning.
The choice of a R9, R10 etc. product is not made at random but established by the standard on the basis of the final use.
The "ASTM" coefficient (U.S.A.)
The ASTM C 1028 standard (Measurement of the static friction coefficient) is used in the U.S.A. for classifying tiles on the basis of their slipperiness.
The Ceramic Tile Institute classifies the tiles in three categories: anti-slip (>0,60), not anti-slip (0,50 – 0,60), and questionable friction (< 0,50). |
