“R” numbers explained
Briefly, R numbers indicate how slippery a tile is – the higher the number, the less slippery it is. For a more detailed explanation, read on.
Ramp test (R numbers) are the European standards for slip resistance in hard flooring, which includes ceramic & porcelain tiles.
The purpose of the test is to rate, on a scale, how resistant the surface is to slipping, in dry & wet conditions, inside & out. The rating will determine what areas the slip resistance of tiles is generally recommended for.
The test is usually performed by the manufacturer & stated in their technical sections of their range catalogues.
It is important to note that the tests are based on floors being correctly fitted, the surface area being properly maintained & cleaned of residual soaps & other contaminates. You should expect a decline in resistance over long periods of wear or excessive traffic.
The slip resistance of a floor in service is dependent upon the surface and its environment. It is important to recognise that this can change significantly with the introduction of a lubricant e.g. water and during the process of installation and finishing. For floors where its anticipated use is likely to involve wetting or other lubricant, contamination slip resistant surface tiles should be used. Generally, dry floors are not slippery but the combination of very smooth floors and hard smooth heel or sole material can be slippery even when dry. Similarly, dry contaminants such as dust, fibres and lint can make any dry, smooth surfaced hard flooring slippery.
R9 – Minor slip resistance, particularly in dry conditions. Suitable for domestic dining & lounge areas & dry bathroom floors
R10 – Minor to moderate slip resistance. Suitable also for hallways, kitchens, bathroom floors, & also commercial use where it is likely to be slightly wet from time to time.
R11 – Moderate slip resistance. Suitable also for potentially wet areas such as shower areas, wet rooms & mostly level outdoor areas. This rating is regarded as a minimum for outdoor use & is the most common for 20mm outdoor porcelain floor tiles.
R12 – High slip resistance. Suitable for all wet areas indoor & out even on moderate sloped floors. Take caution when using these on indoor dry areas, as these are so slip resistant that some may actually cause a trip hazard.
Another method of slip testing which is recommended by The UK Health & Safety Executive (HSE) is the Pendulum test (PTV) which is explained in another section.
