Does self cleaning glass work in balustrades?
Self-cleaning glass is a specific type of glass with a surface that keeps itself free of dirt and grime. Self cleaning glass has a protective coating on the outside of the glass that acts as the ‘self-cleaner’. It uses an organic process whereby dirt is broken down by daylight and is then washed away by rain.
Self-cleaning glass is not a magic solution, but a welcome advance in technology. And like a lot of new technology, it is amazing, but its not cheap and does have some limitations. Self cleaning glass in the UK came about thanks to an intensive research and development programme by the glass manufacturer, Pilkington.
How does self cleaning glass work?
The first stage of the cleaning process is “photocatalytic“. In this stage the coating reacts with daylight to break down organic dirt.
The second stage is “hydrophilic“. Here, instead of forming droplets, rainwater hits the glass and spreads evenly, running off in a “sheet” and taking the loosened dirt with it, also drying quickly without leaving streaks.
Will self cleaning glass work in a balustrade?
Self cleaning glass is designed to be installed at an angle. Specifically it was designed to be used in skylight windows, or for the sides of highrise buildings. The coating needs enough exposure to direct sunlight in order to breakdown dirt. When installed vertically in a balustrade, the glass doesn’t get as much exposure, making its self cleaning properties less effective. The minimum recommended angle is 10° from horizontal so that rain water can flush away loosened deposits.
As the ‘self cleaning’ element of the glass is a coating, it is not advised to be used in areas where there will be traffic. The coating has the potential to scratch and scuff very easily. Once the coating has been scratched/scuffed, it always shows up on the glass. Even the usage of glass suckers when installing would leave visible marks! One glass processor advises wearing cotton gloves when installing the glass to protect the coating.
Pros and Cons
There are several pros to using self cleaning glass, particularly if you dislike the idea of spending a lot of time keeping your glass looking perfect.
There are some things that it will not self clean, like paint or builders dust etc. To remove brick, cement or plaster dust for example will probably need persistence with a water hosepipe. That said, it does what it says on the tin and does over time self clean off the vast majority of organic dirt.
The UV rays in the sun reacts with the dirt to break it down, and then relies on the rain to wash the dirt off. In areas where there is little rain this might not be a good choice of glass.
However, as the ‘self cleaning’ is a coating on the outside, it does have the potential to scratch and scuff easily. Once the outer layer has been scratched/scuffed, it always shows up on the glass.
Self-cleaning glass will prove ineffective if installed under an overhang or in a position where daylight and/or rain cannot reach it, as it has been designed for exterior use only.