Spiral fire door
They have been tested in accordance with BS476. The fire rating was rated by BRE at the Technical Center (Test Report No TE85423) at 4 hours ½ hour to a maximum size of 4000mm wide and 4000mm high.
The special door, which is wrapped in a spiral, closes automatically in cases where the room temperature exceeds 65` at the time of fire, making the fire area isolated.