Wet pendulum Test

Wet pendulum slip resistance testing is recommended where there is a likelihood of the surface being contaminated with any liquid by rain, accidental spillage or ingress.

The wet pendulum test method may be performed either in a testing laboratory or on site.

Applicable Standards

  • AS 4586:2013 Slip resistance classification of new pedestrian surface materials
  • AS 4663:2013 Slip resistance measurement of existing pedestrian surfaces 

As the wet pendulum test can be utilised on existing surfaces it can provide measurements in the inevitable change in slip resistance, enabling the risk of slipping to be monitored. 

The Wet Pendulum Test is conducted using either a Munro Stanley or Wessex friction tester.

The contact surface of the slider material is prepared to a consistent level of smoothness prior to each group of tests.

In operation, a pendulum of a known mass rotates about a vertical spindle. The head of the pendulum is fitted with a Rubber Slider, which has a specific hardness and resilience. When released from a horizontal position, the pendulum head strikes the wetted surface of the test specimen.

The device gives a direct measure of the friction between test foot and floor surface:

A minimum of 5 Repeats of the test are performed for every area

A mean is calculated from the results and then the floor surface can be classified

Except in the case of internal textile floor coverings, AS 4586-2013 requires that the test be performed under wet conditions, and refers to it as the wet pendulum test method.

While either Slider 96 or Slider 55 rubbers may be used depending on the material and its intended application, the test report requires that the rubber that was used be specified.

For surfaces that are particularly slippery, it is appropriate to use slider 96 rubber.