QUESTIONSlip Resistant Tile Floor - What is the criteria for specifying "slip resistant" ceramic floor tile?
ANSWERANSWER - Slip resistance is measured in different ways, and there is some controversy in terms of what is a true indication of a safe surface.
Testing Background: The ASTM C1028 Static Coefficient of Friction test has been the norm for testing slip resistance in the Canadian and USA ceramic tile and stone industry for many years. Most agencies call out codes and recommendations based on this test. Manufacturers use this test to imply the slip resistance of their tiles. The test had been withdrawn from ASTM testing standards, although it was eventually renewed. It has been reported by various testing laboratories and the Ceramic Tile Institute of America (CTIOA) that the C 1028 testing is unreliable in determining if a ceramic tile or stone surface will have a tendency to be slippery or not. The CTIOA is now recommending the allegedly more reliable Tortus Dynamic Test or the British Pendulum Test for the field testing of tile to determine if they have a tendency to be slippery or not. The Tile Council of America of North America (TCNA) recommends the use of the ASTM C1028 test to determine the coefficient of friction and has verbally stated that the ASTM C1028 test is only a measure of the texture of the tile, and does not suggest whether it will be slippery or not. For these reasons we recommend testing the flooring with both test methods.
ASTM C1028 Testing Summary: Test method ASTM C1028 “Standard Test Method for Determine the Static Coefficient of Friction. Generally speaking minimum value is 0.60 for wet surfaces and 0.80 on ramp surfaces.
Surtronic Testing Summary: Test method using the Surtronic 10 digital profilometer used to measure the potential for hydroplaning. A reading below 10 microns is interpreted as likely having an unacceptable potential for hydroplaning.
Tortus Tribometer Testing Summary: Test method using the Tortus Tribometer to measure the dynamic coefficient of friction replicating someone in motion at walking speed, which is a better indicator of the slip potential of a floor than is static friction. The minimum safety standard for this test is 0.50 average whether wet or dry. Reading was based on both a hard rubber material that is close to the rubber on the bottom of typical dress shoes, and based on a soft rubber that simulates a much softer shoe sole typical of athletic shoes.
ANSI A1371. DCOF AcuTest : Latest test method using the BOT 3000 portable tester. A minimum wet value is a DCOF of 0.42.
Keep in mind that slip resistancy on a floor is substantially affected by how clean it is kept. Dirty floors will cause a slip resistant surface to be more slipperly. Generally speaking the more textured the surface the more slip resistant it will be, but also the more textured the surface the more difficult it will be to clean and to keep clean. It is recommended that entrances of buildings have at least 15 foot mat walk-off areas in all directions inside the building from the door entrance to allow shoe bottoms to adequately dry before contacting a dry surface.
CTaSC does provide Services for installation specification, quality control services during the installation, and inspection and testing services for projects.