Safe Environments Assess Slip Resistance of Slippery Carpark
Safe Environments was commissioned to assess slip resistance compliance of a newly constructed concrete carpark . The multi storey carpark was constructed from concrete that was a steel trowel helicopter finish that was sealed. At the time of site inspection, the applicable standard for auditing the slip resistance of the carpark was AS/NZS 4586, Slip resistance classification of new pedestrian surface materials and AS/NZS 4663 Slip resistance measurement of pedestrian surface materials.
The slip resistance of the concrete carpark surface achieved the lowest pendulum slip resistance classification according to AS/NZS 4586. In reference to AS/NZS 4663 the slip test results indicate that the concrete floor affords a very high notional contribution to the risk of slipping when wet. In terms of compliance, Standards Australia & CSIRO Handbook HB 197 An Introductory Guide to the Slip Resistance of Pedestrian Surface Materials is regarded as best practice to document that a carpark surface is non slip or non skid.
In general a roof top carpark should achieve a minimum pendulum slip resistance classification of W; however HB 197 does not specify the minimum slip resistance for the intermediate carpark levels. A slip assessment indicates that the intermediate carpark levels affords a comparable level of risk of slipping to that of an external pedestrian walkway, due to pedestrian interaction with vehicles & expected water tracked in from vehicular flow in wet conditions.
Further slip resistance testing was conducted on concrete surfaces that were both sealed and unsealed. The unsealed concrete was found to achieve a pendulum slip resistance classification of W. The architect had specified that the concrete surface achieve Pendulum Class V, the highest slip resistance classification, when slip tested to AS/NZS 4586. However the builder had not verified that the concrete sealer used, met the Australian slip resistance standards.
Thus the concrete sealer had a dramatic effect on the slip resistance of the concrete surface. The application of a concrete sealer should have been tested on a sample to assess the slip resistance and avoid the potential of a slip and fall accident.