Slip resistance is a very complex area of specification and a poor selection is a difficult problem to rectify. This is generally expensive and intrusive to the operating business of a premises. Insurers are taking tough stances where problems exist, which can have far reaching consequences for the specifiers, owners and/or operators. Getting it right the first time is therefore a very worthwhile investment of time and effort, and treating this area as a "tick the box" selection process is fraught with risk. Specifiers need to be aware that in the event of slip accident, an investigator will likely spend a great deal of time researching the suitability of a selection.

The main selection problem area comes from the lack of a standard that categorically states whether or not a product is suitable. The handbook provides some guidance, but it has not been amended in around 8 years despite its intent to be an “interim” guide. Common traps include:

• Not understanding that test results do vary according to colour, production batch and test accuracy
• Results are grouped into a category and that one R10 may be much better than another R10
• Ramp test angle results do not correspond to the floor slope on which the tile can be used

• Footwear has an enormous influence on practical slip resistance
• Test results are not interchangeable between different test methods
• V surface profile requirements are used together with Ramp scores, not in place of.

R10 tiles are those which score between 10 and 19 degrees on the oil-ramp test—clearly this is a big range of up to 90% variation. The handbook includes a general applications guide (table 3) that states that R10 ( the second lowest ramp category ) is suitable for 17 out of the 20 or so general applications. Given the broad range of what an R10 can be it is little wonder there is potential for slips on an R10 tile

Many people are surprised at the nature of the ramp test commenting that it doesn’t seem very scientific. AS4586 goes into great detail in describing test procedures however it is generally accepted that the test has an error of at least 10%. In fact variation between production batches and colours can each easily contribute further variation error. From this it is clear that a different colour tile from the same range, tested at a different time could produce a significantly different test score. Such a difference could easily change a tile’s category rating

We have seen on many situations where specifiers are under the misapprehension that the Ramp test result means that the tile would be suitable for a ramped or sloping floor of up to that test angle. Note that the ramp test is conducted in industrial rippled sole boots and measured at the point where the tester slips. In a real in use flooring situation, say an access ramp for a railway station, many users would be wearing smooth hard soled shoes and all types of other less slip resistant footwear. The ramp test like all other test only provides a relative measure of one tile verses another.

Footwear makes an enormous contribution to slip resistance. Unofficial ramp tests have demonstrated that certain common types of footwear do not allow any measurable slip resistance when used on the oiled ramp. On this basis the oil ramp test may not be the best method to use when evaluating a tile for a public area flooring selection. The difficulty is this test is the most used by the manufacturers who do not use the pendulum test and are therefore under no obligation to produce products that achieve any particular pendulum result.

Test results are not interchangeable between test methods. The only correlation between different tests is that generally products that perform better on one test will generally be better on all. R10 tiles have been measured with pendulum results ranging across three or four different pendulum classifications.

The requirement for a V profile is in addition to the slip resistance rating where recommended in Handbook HB 197. Metz have seen published literature recommending compliance with the Handbook and ignoring the requirement for V rated profiled surfaces—such is the level of confusion with this issue. Metz do believe that surface texture is a suitable way to achieve a slip resistant floor for many applications where the handbook currently requires a profiled finish. This is based on our long experience of using R13 rated tiles with textured finishes. Ultimately the final decision whether to use a profiled surface rests with the specifier.