When selecting ceramic or porcelain tiles, it is crucial to think about slip resistance in addition to water absorption rate and hardness, particularly for flooring in wet locations like bathrooms, outdoor car porches, and others. The primary concern in areas where tiles will be exposed to water is the tile’s anti-slip rating.
How is Slip Resistance of Tiles Measured?
The slip resistance of tiles is typically assessed using three main methods: the Oil Wet Ramp Test, the Dry Friction Test (Tortus), or the Wet Pendulum Test, which assign surfaces ratings like ‘R’, ‘COF’, or ‘P’ respectively.
- Oil Wet Ramp Test
The Oil Wet Ramp Test requires one or more individuals to walk back and forth on a platform with tiled surfaces. The ramp’s incline is gradually increased until slipping happens. The angle at which slippage occurs is measured to establish the tile’s slip resistance rating, known as the R-rating. The R value varies from R9 (6 to 9 degrees incline) to R13 (35 degrees and above), with R9 indicating the lowest slip resistance level and R13 indicating the highest slip resistance level. - Dry Friction Test (Tortus)
During the Dry Friction Test, the slip resistance of a tile is evaluated by measuring the friction generated by a rubber slider as it moves across a tile sample. This assessment is conducted with a specific tool known as the Tortus, hence the test is also referred to as the Tortus Test. The outcome is presented as a coefficient of friction (COF) ranging from 0 to 1, with higher values indicating better slip resistance of the tile. Tiles must have a minimum COF of 0.4 to be deemed suitable for floor installation.
