Fire Test Standards - Doors

The current and most widely quoted testing standard to doors is still BS 476: Part 22.Their is also the more recently introduced European standard for fire door testing which is BSEN 1634-1. It may be expected that the EN test standard could eventually replace the BS test standard but at this time, they are both separate testing standards with many similarities and some significant differences between the two standards in testing criteria.

With both the BS and EN testing standards, thermocouples are used to record furnace temperatures on the exposed surface of the test specimen. In the BS test standard, these thermocouples are of mineral insulated materials, whereas the EN standard uses thermocouples which are both larger and made of metal plate. The effect that this has on the EN test is that more fuel is required in the initial stages of the test in order to get the metal plate thermocouples to react and therefore give the required temperature reading than is required by the fibrous thermocouples used in the BS test. This results in the doors being exposed to more severe environment at the initial test period.

Another significant difference is in pressures on the exposed surface of the test specimen. In the BS test there is a negative pressure zone on the lower section of the door below lock height whereas in the EN test standard the test specimen is under positive pressure over the entire product surface. The result is that although the threshold is still in negative pressure the airflow could be reduced. The test specimen is therefore put under greater positive pressure in the EN test than would be when tested to the BS standard. The extra pressure subjects the test specimen to more stress which can, among other points, cause more deflection and can be considered a more aggressive test This extra or increased pressure can also result in increase erosion of the test specimen, particularly at the junction between door leaf, intumescents and frame.