How thick does fire door glass have to be?

[Guest Natpal]

We would like to know how thick glass fire rated doors must be (1 hour). Many thanks

[Tom Sutton]

The thickness of the glass is incidental the whole doorsets has to be tested to BS 476 or BS EN 1634 and have achieved integrity of the required fire resisting standard. The test certificate is the proof of the fire resisting rating and the accompanying literature how the door should be installed with other relevant information.