The growing trend in Australian tile specification is to spec P5 for everything. Certifiers love this but it is often a terrible idea.
Surfaces that will give a P5 test are great out of the crate but can rapidly degrade in slip resistance over time due to cleaning and chemical buildup, wear, and weathering.
The below table is a brilliant guide to specifying slip resistant requirements by application.
So how can specifying materials with a higher slip resistance work against us? Slip resistance comes from three main properties: porosity, surface area in contact, and texture. P4 and P5 surfaces will generally have a higher porosity like that found in basalt, or alternatively have a sandblasted or sandblast imitation surface.
When we work with these materials of high slip resistance in areas of high use like shopping centres, shared walk ways, public building entrances, etc. The use and maintenance work against the slip rating.
Constant cleaning with residual chemicals and common cleaning practices builds up within the porosity and amongst the texture. This reduces the slip resistant nature of the surface leaving it unpredictable and slippery especially when wet.
Foot traffic, walk behind brush sweepers and ride on cleaners using brush systems can also have an adverse effect on high slip resistant materials. The constant wear on the stone can smooth the aggressive surface reducing the surface area and dramatically increasing the slip. They will also smooth the porosity of stone making the surface more unified. This greatly reduces the slip resistance over time.
Lithic Australia has the knowledge and skill to help you find the right material for your project. Utilising the correct material initially will allow your stone to be maintained and cleaned with predictable and standardised practices. This in turn, ensures the slip resistance will be maintained over time.