There is much confusion and many rumors running around regarding the correct type of glass allowed on balconies and balustrades.
This stems from two reasons; the first being lack of understanding of the required standards and the second a vested interest in sending customers towards a specific product.
I have had customers calling regards a juliet balcony saying they have been told they need to use 15mm toughened glass, or someone who wanted to glaze a landing staircase was told he had to use 19mm toughened glass. Both of the above turned out to be unnecessary and they had their railing made with 10mm toughened.
Definition of toughened glass: Glass that has undergone treatment also called “tempering” where the glass is heated to close to seven hundred (700) degrees Celsius and using air cooled quickly creating a strong layer on both faces of the glass while locking inside the glass a lot of tension. This causes the glass to become more resistant to impact four times more than regular float glass. When toughened glass breaks it will shatter into thousands of small glass pieces and therefore, not dangerous little bits.
Definition of laminated glass: Safety glass that is made from two or more glass panels with a plastic or resin based interlayer that is allowed to break under impact but must not allow the impacting body to penetrate the panel.
Throughout Europe, excluding the UK, single pane toughened glass is not allowed. Only laminated glass is allowed. But in the United Kingdom the majority of glass used in balustrades is toughened. Laminated glass is slowly becoming more widely used. Due to the extra cost of laminated glass I believe that until legislation turns this into a requirement toughened glass will remain number one in balconies and balustrades.
Thickness and type of glass depends on:
1) The area it must protect
2) Impact class required
3) Size of each single pane used.
4) The distance or depth of the balcony or terrace and..
5) The type of railing, balustrade or balcony
There are three British standards that are relevant to glass classification and specification on Balconies, railings and balustrades: BS6180, BS6399:1 and BS6206.
Please feel free to ask any specific question.