Today a majority of floor tiles are given an anti-slip rating. This rating comes in the form of an “R” value, which stands for “Ramp Test”.
R9: Minimal Friction
When wet, tiles will receive this low rating and are typically smooth glazed matte finish. Used in domestic bathrooms, it is recommended to use a bath mat or towel to prevent fall.
R10: Normal Friction
Mostly consisting of glazed tiles, flooring with this rating may be used in other domestic areas besides the bathroom, such as the kitchen, living areas, and hallways.
R11: Normal Friction
R12: High Friction
Including both glazed and unglazed tiles that have these ratings may be regarded as safe for installations of wet rooms, bath, kitchen, porches, and living areas. Examples of public areas that can use this rating of floor are communal showers, swimming pool surrounds, shopping centers, and hotel foyers. If the flooring is porcelain it is suitable for external situations.
R13: Very High Friction
Tiles of this grade will be both glazed and unglazed and are acceptable flooring for all commercial and residential projects both internally and externally. These are the most common used for pool surrounds, public showers, or changing rooms.
The Coefficient of Friction (COF) of a tile is a measure of the “slip resistance” of a tile.
STATIC COF - This is the force required to START something moving. Imagine you are standing still…it is the force between your shoe and the floor to get you from stopped to moving. If you apply a LOT of force, you slip. This test shows the amount of force needed JUST BEFORE you slip.
DYNAMIC COF - This is the force required when something is in motion. Imagine you are walking, the more pressure you apply, the faster you will go. This test shows the amount of force needed just before you slip WHILE you are already in motion.