Fire ratings
All of our sloping patent glazing systems have a designation AA as defined in BS 476: Part 3 when they are installed with an infill such as 6mm wired cast glass or other glasses of at least 4mm thick.
If elements of the structure have need for a level of fire resistance when tested in accordance with BS 476: Parts 20 and 22, certain types of patent glazing will be suitable. These may either be tested or approved as ‘deemed to satisfy’ by fire authorities or local authority building inspectors.
A joint venture by the Patent Glazing Contractors Association and Pilkington Glass Ltd was organised to test the heat resistance of patent glazing when subjected to smoke temperatures. This test was carried out at Warrington Fire Research Centre and produced the following results.
The test sequence attempted the following furnace temperatures:
- 300°C for 30 minutes
- 400°C for 15 minutes
- 500°C for 15 minutes
- 600°C for 30 minutes
The results demonstrated that all aluminium and lead covered steel (Heritage) glazing bars should perform adequately at smoke temperatures up to 600°C. Laminated glass of nominal 6.4mm thickness remained intact up to 400°C, and toughened glass of nominal 6mm thickness remained intact at 600°C, highlighting the importance of selecting appropriate materials when considering fire ratings for patent glazing to ensure compliance with fire safety standards.