Porcelain Paving Slab Finishes

Porcelain pavers intended for outdoor use are specifically designed to walk on and minimise the slip risk using grippy surfaces. By using imperfections and ridge marks to increase the friction between a tile and your shoe, you create a surface fit to walk on in differing conditions. We can calculate this using a test designed to calculate the pendulum test values (PTV) and assign a numerical value to the performance of a surface. Look out for the appropriate feature when you browse our porcelain pavers.

A rig is set up above a test surface that holds the pendulum arm parallel to the test surface. This arm is at a length so that it comes into contact with the surface when it is perpendicular.

When the pendulum comes into contact with the surface (for example, a test tile), it loses some of its kinetic energy to friction. This loss will mean the swing will not finish at 90 degrees to the surface, and we can measure the change in final height. This is the coefficient of friction (CoF) and it gives us our PTV value.

There are several testing conditions; slider 96 and Slider 55, and wet and dry:

– Slider 96/55 – You place rubber sliders on the end of the pendulum.
– Slider 96 is a harder rubber, so you use it to emulate the effect of pedestrians wearing shoes.
– Slider 55 is a softer rubber, often used to mimic walking with bare feet.

When these tests are conducted, the tests are often done in wet and dry conditions to fully understand the range of slippiness.

The results that come from the PTV test only give an indicator of how slippery the finish is, or the slip potential. Many other factors will influence how they behave underfoot, but this gives us an accurate idea.

The results you get go from 0 upwards, where:
– 0 – 24 is a high slip potential.
– 25 – 35 is a moderate slip potential.
– 36+ is a low slip potential.

When temperatures drop to the freezing point, ice can begin to form on the paving, making it very slippery.

“Where weather or low-temperature results in surfaces being covered in snow or ice, the slip resistance of a surface ceases to be effective.” – BS8 300

It is, therefore, important that external ramp surfaces are kept free of snow or ice as part of the management regime of the space.

Typically, porcelain tiles for outdoor applications sit in the £30-£70 per square metre price bracket, but in some cases can cost less for very basic finishes. Though it may be tempting to opt for the budget option, consider and calculate the long-term costs first. What you save in the short term, you might pay twice over in the long term. Particularly if you choose tiles that are more prone to cracking or damage.