Glass can become slippery when wet and common sense should be applied when specifying this material for walk on applications such as walk on rooflights. This is of particular importance when the glass is being installed where the public can access it.
On a private dwelling it is less likely that the glass will be used if it is raining, but the same cannot be said for commercial and public applications.
Applying an anti-slip glass surface finish to glass that is designed for walk-on applications should always be considered; the same finish can also provide some obscurity to the glass if required.
A screen printed frit that includes particles within the ink to create a rough texture can be applied to the glass in a variety of patterns, which will significantly increase the slip resistance of the glass. Alternatively the surface of the glass can be sand blasted which will result in more diffused light and improved obscurity.
Slip resistance is measured using mean Pendulum Test Values (PTV); the higher the figure the better the slip resistance.
A PTV of 0-24 has a high slip risk, 25-35 has a moderate slip risk and 36+ has a low slip risk. The test is carried out in wet and dry conditions and the lowest figure is obtained when wet.
Generally sandblasted glass achieves a PTV of 50 and fritted glass achieves a PTV of 60, providing better slip resistance than the sandblasted. However both are well above the threshold of 36 to be categorised as having a low slip potential.